Merge upstream/main into fix/text-mixed-fill-section

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

.github/workflows/release.yml

@@ -48,3 +48,4 @@ jobs:
       AZURE_SIGNING_ENDPOINT: ${{ secrets.AZURE_SIGNING_ENDPOINT }}
       AZURE_SIGNING_ACCOUNT: ${{ secrets.AZURE_SIGNING_ACCOUNT }}
       AZURE_CERT_PROFILE: ${{ secrets.AZURE_CERT_PROFILE }}
+      LINUX_SIGNING_KEY: ${{ secrets.LINUX_SIGNING_KEY }}

Cargo.lock

@@ -1157,6 +1157,15 @@ dependencies = [
  "zip 9.1.1",
 ]
 
+[[package]]
+name = "craft-web-host"
+version = "0.1.0"
+source = "git+https://github.com/storytold/craft-libs?rev=2e2312ddaf21bc3d85cd3395d0955c7d239306f6#2e2312ddaf21bc3d85cd3395d0955c7d239306f6"
+dependencies = [
+ "wasm-bindgen",
+ "web-sys",
+]
+
 [[package]]
 name = "craft-window"
 version = "0.1.0"
@@ -2121,6 +2130,7 @@ name = "figcraft-web"
 version = "0.15.0"
 dependencies = [
  "base64 0.22.1",
+ "craft-web-host",
  "eframe",
  "egui",
  "figcraft-collab-net",

ROADMAP.md

@@ -2,7 +2,7 @@
 
 **Stage: alpha** · next: beta, ~26 points and ~162–292 h away (one Opus 5.5 agent; ~33–67 h wall-clock with 5 agents)
 
-> **Last reviewed:** 2026-10-10 · **Last updated:** 2026-10-30 · **Change:** minor (a connector end moved with Cmd/Ctrl held goes on any part of an object, and stays there as the object moves or resizes; a tap on a plugin panel's button keeps what was typed in its fields; a Dash cap setting (none, round or square) on Dash and Custom strokes, drawn on both ends of every dash; library analytics list how many layers and files use each style and variable; the Controller menu names each button as PlayStation and Switch controllers do; widgets draw lines and SVG pictures (plugin API 6); a connector end dropped along a side of a shape attaches to that side (#1708); regression tests pin a rounded shape's one-sided stroke and SVG ids and font families without XML-forbidden characters (#1351, #1124); a damaged image is refused with a reason instead of showing as an empty box (#1474); an image copied in another app pastes again on the desktop, and in the browser for the first time (#492); SwiftUI and Compose code names a bound variable by its iOS or Android code syntax; the colour picker's Image tab shows a placeholder and Upload from computer, an asset preview, and a file dropped on it replaces the image, keeping the fill mode, crop and position (#1682); the Frame tool's Phone presets have the iPhone 17 family (#1691); Show in folder works in the Flatpak build and selects the file on Linux (#1701); a dashed line starts and ends with a half-length dash, on the canvas and in exports; the Pages, Layers and Assets search fields keep their text in the middle of the field (#1703); a board connector's path can be reshaped by dragging its path handles (#1710); boards have 16 more shapes (arrows, polygons, star, plus and flowchart symbols), in pickers that lay them out in a grid; library analytics count insertions and show insertions and detachments over the past 30 days, 90 days or year; a stroke's Custom style takes a dash pattern of any length as a comma-separated list (#1681); a control request can set its own timeout, up to 10 minutes (`timeoutMs`; `figcraft-cli mcp --attach PORT --timeout SECONDS`) (#1696); gap 6: a widget opens its plugin's panel (plugin API 5), whose callbacks redraw it; the keyboard's Menu key opens the context menu, as Shift+F10 does; an Open link action can open in place of the prototype, with "Open in new tab" off (gap 15); a collection of this file can be extended (Extend collection on its row, `variable.extendCollection`), its extension following its edits at once, and extended collections extend again in the file; the eyedropper with Cmd/Ctrl+Shift makes a colour style or variable of what it picks; a live session's welcome sends the document compressed to clients that read it, about seven times smaller (#1665); a control request that times out says truthfully whether it was dropped or is still running and will take effect, and only screenshots and input blame the window (#1673); a board keeps earlier votes' results, listed newest first in Results and deleted one at a time; the object a stamp will stick to is outlined while the stamp tool is over it or a stamp is dragged over it, and board objects take no drops (gap 24); a server can list the files shared from it now for everyone who reaches it, Home ▸ Online shows them and their links carry no secret (`team_files`, part of #742); team library analytics count detached instances per component and file (gap 10); skipping the Open link notice by command is saved with the preferences at once (gap 15); a selected connector's bar on a board sets its start and end points, solid or dashed, its weight and any colour (#1596); cells copied from a spreadsheet paste onto a board as a table; a long layer name stays on one line in the Export button and the Dev Mode header, ending with an ellipsis, and no longer covers the Design panel (#1650); with hundreds of layers selected, the Design panel and the selection overlays stop going over the whole selection on every frame, so dragging 648 layers averages about 1.1 ms of UI per frame (#1571); plugin panels show pictures: an `image` control, base64 within 256 KB and 4,096 px a side, named by its label (gap 6); `.fig` connector labels without a saved snapshot are kept, centred on their line (gap 1); a drag moving many layers re-runs only what sits around them, not each layer's bindings, sizing, text and instance checks, on every move (#1571); damaged font tracking table offsets are checked instead of wrapping on 32-bit targets, and font indexing makes its existing offset bounds explicit (#1125); Bosnian (`bs`) draft catalog; text style dedupe is O(spans) via a last-two cache and fingerprint buckets (#1102); pasted layers whose image the clipboard lacks are named and show a placeholder that reads as missing (#1646); paint-style colours on layers pasted from another design app keep their style instead of turning black (#1638); progress docs cleaned of what merges left twice: rows merged into one, repeated statusLine truncated
+> **Last reviewed:** 2026-10-10 · **Last updated:** 2026-11-02 · **Change:** minor (glass bends with a thick-lens profile and splits its colours over 8 steps; glass effects take variables and keep their frost within 0–100; web host bridge: `?host=parent` or `data-host="page"` hands a page the app's files, documented in the hosting guide; a connector end moved with Cmd/Ctrl held goes on any part of an object, and stays there as the object moves or resizes; a tap on a plugin panel's button keeps what was typed in its fields; a Dash cap setting (none, round or square) on Dash and Custom strokes, drawn on both ends of every dash; library analytics list how many layers and files use each style and variable; the Controller menu names each button as PlayStation and Switch controllers do; widgets draw lines and SVG pictures (plugin API 6); a connector end dropped along a side of a shape attaches to that side (#1708); regression tests pin a rounded shape's one-sided stroke and SVG ids and font families without XML-forbidden characters (#1351, #1124); a damaged image is refused with a reason instead of showing as an empty box (#1474); an image copied in another app pastes again on the desktop, and in the browser for the first time (#492); SwiftUI and Compose code names a bound variable by its iOS or Android code syntax; the colour picker's Image tab shows a placeholder and Upload from computer, an asset preview, and a file dropped on it replaces the image, keeping the fill mode, crop and position (#1682); the Frame tool's Phone presets have the iPhone 17 family (#1691); Show in folder works in the Flatpak build and selects the file on Linux (#1701); a dashed line starts and ends with a half-length dash, on the canvas and in exports; the Pages, Layers and Assets search fields keep their text in the middle of the field (#1703); a board connector's path can be reshaped by dragging its path handles (#1710); boards have 16 more shapes (arrows, polygons, star, plus and flowchart symbols), in pickers that lay them out in a grid; library analytics count insertions and show insertions and detachments over the past 30 days, 90 days or year; a stroke's Custom style takes a dash pattern of any length as a comma-separated list (#1681); a control request can set its own timeout, up to 10 minutes (`timeoutMs`; `figcraft-cli mcp --attach PORT --timeout SECONDS`) (#1696); gap 6: a widget opens its plugin's panel (plugin API 5), whose callbacks redraw it; the keyboard's Menu key opens the context menu, as Shift+F10 does; an Open link action can open in place of the prototype, with "Open in new tab" off (gap 15); a collection of this file can be extended (Extend collection on its row, `variable.extendCollection`), its extension following its edits at once, and extended collections extend again in the file; the eyedropper with Cmd/Ctrl+Shift makes a colour style or variable of what it picks; a live session's welcome sends the document compressed to clients that read it, about seven times smaller (#1665); a control request that times out says truthfully whether it was dropped or is still running and will take effect, and only screenshots and input blame the window (#1673); a board keeps earlier votes' results, listed newest first in Results and deleted one at a time; the object a stamp will stick to is outlined while the stamp tool is over it or a stamp is dragged over it, and board objects take no drops (gap 24); a server can list the files shared from it now for everyone who reaches it, Home ▸ Online shows them and their links carry no secret (`team_files`, part of #742); team library analytics count detached instances per component and file (gap 10); skipping the Open link notice by command is saved with the preferences at once (gap 15); a selected connector's bar on a board sets its start and end points, solid or dashed, its weight and any colour (#1596); cells copied from a spreadsheet paste onto a board as a table; a long layer name stays on one line in the Export button and the Dev Mode header, ending with an ellipsis, and no longer covers the Design panel (#1650); with hundreds of layers selected, the Design panel and the selection overlays stop going over the whole selection on every frame, so dragging 648 layers averages about 1.1 ms of UI per frame (#1571); plugin panels show pictures: an `image` control, base64 within 256 KB and 4,096 px a side, named by its label (gap 6); `.fig` connector labels without a saved snapshot are kept, centred on their line (gap 1); a drag moving many layers re-runs only what sits around them, not each layer's bindings, sizing, text and instance checks, on every move (#1571); damaged font tracking table offsets are checked instead of wrapping on 32-bit targets, and font indexing makes its existing offset bounds explicit (#1125); Bosnian (`bs`) draft catalog; text style dedupe is O(spans) via a last-two cache and fingerprint buckets (#1102); pasted layers whose image the clipboard lacks are Line truncated
 
 FigCraft is a clean-room, open-source, pure-Rust reimplementation of the Figma design workflow,
 native on macOS, Windows, Linux and FreeBSD and in the browser, fully drivable by agents through
@@ -143,6 +143,7 @@ Ranked; detail and milestones in [`docs/roadmap.md`](docs/roadmap.md).
 - **2026-10-27** · Batch continue-on-error (M0.9, #1386): `command.batch` and MCP `batch` accept `onError: "continue"`, roll back failed steps individually and return one outcome per step. References to failed steps fail with both step numbers; successful edits stay one undo step, and the default abort mode is unchanged. Engine and MCP regression tests. Numbers unchanged.
 - **2026-10-26** · Non-ASCII layer names transliterate in code export (M6, #1235): `class_name` runs the name through `deunicode` before its ASCII filter, so 로그인 화면 → `rogeuin-hwamyeon`, кнопка → `knopka`, über → `uber` in the HTML/CSS/React/Leptos class names, component roots and `data-*` variant attributes (SwiftUI/Compose type names unchanged); a name left with nothing (symbols only) takes the node's kind (`.text`, `.frame`) instead of `layer-`, and the 40-character cut lands on a word boundary. New dependency: deunicode (pure Rust tables, zero deps, BSD-3-Clause, the `slug` crate's base). `html_codegen_tests`. Numbers unchanged.
 - **2026-10-25** · M6, #1143: offline Penpot 2.x open/import/export through the editor, CLI and MCP using the existing document model. Unsupported layout settings retain saved positions and bounded source metadata with warnings; font binaries and toggle-overlay are reported, and provider fonts are never downloaded. Shared ZIP/JSON/token budgets guard untrusted input. Figma parity numbers unchanged.
+- **2026-10-26** · Web host bridge: `?host=parent` (a same-origin page embedding FigCraft in an iframe) or `data-host="page"` on the canvas (the page's own document, over non-bubbling `CustomEvent`s) opens the host's file like File ▸ Open (over the browser open limit of 512 MB refused) and takes every file the app would otherwise download (`figcraft:save` with the `saveAs` rule), plus `figcraft:dirty`, `figcraft:ready` and `figcraft:failed`; `?author=` names the user for comments and board notes; host mode starts with no document. Unit tests cover the opt-in rule (only the exact `page` value), the `saveAs` rule and the open-name fallback. Numbers unchanged.
 - **2026-10-25** · egui 0.37 capture lifecycle: screenshots with hidden or unknown visibility queue, request a hidden paint, and expire after 60 seconds if no capture arrives (headless-tested contract). Logic-only edits, saves and inspection continue while hidden. Native visible GUI and forced hidden-window paint, browser and Wayland behavior remain unqualified; parity percentages are unchanged.
 - **2026-10-24** · Open, Save and the folder dialogs start in the folder of the last file or folder picked in the run (#1290): the Linux portal does not remember it between dialogs as the macOS and Windows panels do. A folder deleted since falls back to the system's choice. No numbers change.
 - **2026-10-24** · Boards (M12): board pages get a dot grid under their layers (drawn by the canvas render after the page colour, thinned out when zoomed out); a selected connector shows its ends as handles, and dragging one onto another object re-attaches it there, onto empty canvas leaves it free (`board.reattach`, one undo step, also over MCP); connectors can be curved, and elbows go around the objects they join when the short way would cross them. Checked in the app, through MCP and in the web build ([boards-parity](docs/boards-parity.md)).
@@ -357,6 +358,8 @@ Ranked; detail and milestones in [`docs/roadmap.md`](docs/roadmap.md).
 
 | Date | Change | Summary |
 |---|---|---|
+| 2026-11-02 | minor | M3, #1885: glass bends the backdrop with the reference tool's thick-lens profile: most a 1-unit bevel in from the edge, falling off as the 3.5th power of the way out of the curve to nothing `depth` further in, and a fifth as much on the bevel itself (it fell off as the square of the way in from the very edge). Dispersion splits the channels over 8 steps with a triangular window, red moving furthest and blue least, as far apart as the reference tool's (at 100% red and blue move 0.16 of the bend apart; it was three samples, blue furthest), and `Glass::max_bend` bounds red's furthest step, so the backdrop read around a pane covers every sample. Tests: `glass::tests::the_bend_follows_the_thick_lens_profile`, `glass::tests::dispersion_splits_the_channels_along_the_bend`. Numbers unchanged |
+| 2026-11-02 | minor | M3, #1885: glass effects take variables (light angle, intensity, refraction, depth, dispersion, frost and splay, on layers and in effect styles, and from the Design panel's glass fields), and a glass's frost stays within 0–100, the reference tool's range: a larger frost from an older file draws at 100, and the field, a bound variable and scaling stop there. Numbers unchanged |
 | 2026-10-31 | minor | M12: as the help describes, holding Cmd/Ctrl while moving a connector's end places it on any part of an object instead of snapping to a side. It keeps that spot as a fraction of the object's box, so it follows the object when it moves or resizes, and without the key an end snaps as before. `board.connector {fromAt, toAt}` and `board.reattach {at}` take it; saved only when set. Numbers unchanged |
 | 2026-10-31 | patch | M11: a trackpad or touch tap sends its press and release in one frame, so a plugin panel's field committed in the frame its button was clicked and the value was lost: the Counter's Set count… kept the old count. The plugin now gets both, the field's value first. The `window.figcraft` docs name `screenshot`'s `data`. Numbers unchanged |
 | 2026-10-31 | patch | M4: Dash and Custom strokes have a Dash cap (None, Round, Square) in the advanced stroke settings and `node.set {dashCap}`, on both ends of every dash on the canvas and in PNG, PDF and SVG. Unset, dashes keep taking the end point caps, so older files look the same; the saved file writes it only when set. Numbers unchanged |
@@ -492,6 +495,7 @@ Ranked; detail and milestones in [`docs/roadmap.md`](docs/roadmap.md).
 | 2026-10-27 | minor | Placed images keep their own size (M7, #1360): dropping, Place image, paste and `image.place` put an image at its pixel size and fit only a side past 4096 px (they fitted it into 1000 px); a PNG whose `pHYs` records a whole 2x–4x multiple of 72 dpi (macOS screenshots record 144 dpi) is placed at its point size, so an 800 × 600 px capture comes in at 400 × 300; other densities, such as 300 dpi scans, keep their pixel size; the image data stays at full resolution and an explicit width or height still wins. On macOS, paste reads the clipboard's PNG as is (its density and colour profile kept) and falls back to the decoded image. Numbers unchanged |
 | 2026-10-26 | minor | Non-ASCII layer names transliterate in code export (M6, #1235): `class_name` transliterates through the new `deunicode` dependency (pure Rust tables, zero deps, BSD-3-Clause), so Korean, Cyrillic, Latin-diacritic and CJK names become readable ASCII classes (`rogeuin-hwamyeon`, `knopka`, `uber`, `an-niu`) in HTML/CSS/React/Leptos output, component roots and `data-*` variant attributes; symbols-only names take the node's kind (`.text`) instead of `layer-`, and the 40-character cut lands on a word boundary. `html_codegen_tests` updated and extended. Numbers unchanged |
 | 2026-10-25 | minor | M6, #1143: offline Penpot 2.x open/import/export through the editor, CLI and MCP using the existing document model. Unsupported layout settings retain saved positions and bounded source metadata with warnings; font binaries and toggle-overlay are reported, and provider fonts are never downloaded. Shared ZIP/JSON/token budgets guard untrusted input. Figma parity numbers unchanged. |
+| 2026-10-26 | minor | Web host bridge: `?host=parent` (a same-origin page embedding FigCraft in an iframe) or `data-host="page"` on the canvas (the page's own document, over non-bubbling `CustomEvent`s) opens the host's file like File ▸ Open and takes every file the app would otherwise download, with `figcraft:ready`, `figcraft:open`, `figcraft:save` (a `saveAs` rule), `figcraft:dirty` and `figcraft:failed`; `?author=` names the user for comments and board notes; documented in the hosting guide. Numbers unchanged |
 | 2026-10-25 | minor | egui 0.37 capture lifecycle: screenshots with hidden or unknown visibility queue, request a hidden paint, and expire after 60 seconds if no capture arrives (headless-tested contract). Logic-only edits, saves and inspection continue while hidden. Native visible GUI and forced hidden-window paint, browser and Wayland behavior remain unqualified; parity percentages are unchanged. |
 | 2026-10-24 | minor | Server memory (#1134): when the last person leaves a file nobody edited, figcraft-server keeps the client ids it issued in the log instead of rewriting the snapshot (compaction still follows `compact_after`/`compact_mb` and edits), and a snapshot is encoded straight into its file buffer, without a second copy of the body; the file format is unchanged. Numbers unchanged |
 | 2026-10-24 | minor | Boards (M12): a dot grid on board pages under the layers, connector ends dragged onto other objects or empty canvas (`board.reattach`), curved connectors, elbows that go around what they join. Boards row ~35% → ~37%, ~20% → ~21%, 30–60 h → 28–56 h; headline numbers unchanged (boards are outside the weighted sum) |

apps/figcraft-cli/src/perf.rs

@@ -498,7 +498,8 @@ fn measure_components(table: &mut Table, col: usize, instances: usize) -> CliRes
     static RUNS: std::sync::atomic::AtomicUsize = std::sync::atomic::AtomicUsize::new(0);
     let run = RUNS.fetch_add(1, std::sync::atomic::Ordering::Relaxed);
     let dir = std::env::temp_dir().join(format!("figcraft-perf-{}-{run}", std::process::id()));
-    std::fs::create_dir_all(&dir).map_err(failed)?;
+    // `create_dir`, not `create_dir_all`: a directory or link already at this predictable name is refused.
+    std::fs::create_dir(&dir).map_err(failed)?;
     let path = dir.join("design-system.figcraft").to_string_lossy().into_owned();
     let (lib_doc, lib_ds) = design_system_document(&spec).map_err(failed)?;
     let mut lib_s = Session::with_document(lib_doc);

apps/figcraft-server/src/admin_budget_tests.rs

@@ -75,3 +75,11 @@ fn codes_are_found_through_the_index_as_before() {
     assert_eq!(store.resolve_code(who(105), &codes[2]).unwrap_err(), CODE_GONE);
     assert_eq!(store.resolve_code(who(106), &codes[3]).unwrap().0, files[3].0);
 }
+
+#[test]
+fn a_name_taken_from_the_file_is_cleaned_like_a_given_one() {
+    let dir = TempDir::new("embedded-name");
+    let mut store = Store::open(dir.path(), config(dir.path()).store()).unwrap();
+    let (file, ..) = store.publish("", &snapshot("Bad\u{1b}[2Jname\u{202E}")).unwrap();
+    assert_eq!(file.name, "Bad[2Jname");
+}

apps/figcraft-server/src/store/files.rs

@@ -95,8 +95,9 @@ impl Store {
             return Err(format!("the file has more than {} layers", self.cfg.core.max_nodes));
         }
         let mut doc = replica.document().clone();
+        // The name the file keeps, whichever one it comes from, is cleaned.
         let name = match clean_name(name) {
-            n if n.is_empty() => doc.name.clone(),
+            n if n.is_empty() => clean_name(&doc.name),
             n => n,
         };
         doc.name = name.clone();

apps/figcraft-web/Cargo.toml

@@ -19,6 +19,8 @@ figcraft-format = { workspace = true }
 figcraft-ui-egui = { workspace = true }
 figcraft-collab-net = { workspace = true }
 figcraft-text = { workspace = true }
+# The host messages (storytold/craft-libs): one contract and one bridge for the web builds.
+craft-web-host = { git = "https://github.com/storytold/craft-libs", rev = "2e2312ddaf21bc3d85cd3395d0955c7d239306f6", version = "0.1.0" }
 base64 = { workspace = true }
 egui = { workspace = true }
 log = { workspace = true }
@@ -30,4 +32,4 @@ eframe = { workspace = true, features = ["default_fonts", "wgpu", "accesskit"] }
 wasm-bindgen = "0.2"
 js-sys = "0.3"
 wasm-bindgen-futures = "0.4"
-web-sys = { version = "0.3", features = ["Window", "Document", "Element", "HtmlCanvasElement", "HtmlElement", "HtmlAnchorElement", "Node", "Blob", "BlobPropertyBag", "ClipboardEvent", "DataTransfer", "File", "FileList", "HtmlInputElement", "EventTarget", "Url", "Location", "MediaQueryList", "Navigator", "Gamepad", "GamepadButton", "GamepadMappingType", "Storage"] }
+web-sys = { version = "0.3", features = ["Window", "Document", "Element", "HtmlCanvasElement", "HtmlElement", "HtmlAnchorElement", "Node", "Blob", "BlobPropertyBag", "ClipboardEvent", "DataTransfer", "File", "FileList", "HtmlInputElement", "EventTarget", "Url", "Location", "MediaQueryList", "Navigator", "Gamepad", "GamepadButton", "GamepadMappingType", "Storage", "Event", "MessageEvent", "UrlSearchParams", "CustomEvent", "CustomEventInit"] }

apps/figcraft-web/src/host.rs

@@ -0,0 +1,143 @@
+//! Host modes: a page that runs FigCraft (as an `<iframe>`, or in its own document) opens
+//! documents in it and stores what it saves instead of the browser downloading. The messages
+//! and the two transports are `craft-web-host`'s (storytold/craft-libs): the same contract as
+//! the other Craft apps' bridges. This module is FigCraft's part of it.
+//!
+//! - `?host=parent` (an `<iframe>`, such as a Nextcloud app) talks to the same-origin parent over
+//!   `postMessage`; `data-host="page"` on the canvas (the page's own document) uses DOM
+//!   `CustomEvent`s on the canvas instead. `?host=parent` wins when both are present.
+//! - `figcraft:ready` (to the host) once the app is running and listening; send a file now.
+//! - `figcraft:open` (from the host): `{ name, bytes }`. It opens exactly as a file picked with
+//!   File › Open or dropped on the window would (the app's own open queue, with its "Opening as
+//!   a new file" card). A payload over the browser's own open limit
+//!   ([`figcraft_ui_egui::browser_can_read`]'s 512 MB) is refused before its bytes are copied,
+//!   and anything malformed is ignored. FigCraft reads whole files, so it says `file: false` in
+//!   `ready` and a host sends `bytes`.
+//! - `figcraft:save` (to the host): `{ name, saveAs, bytes }` for every file the app hands its
+//!   download service; in host mode nothing reaches the browser's downloads. `saveAs` says whether
+//!   the file becomes the document's file ([`crate::hostmode::save_as`]):
+//!   - A Save of the file the host opened, under its own name: `false`.
+//!   - A document file (`.figcraft` or `.json`, the formats `file.save` and `file.saveAs` write)
+//!     under a name the host didn't open — Save As, or a Save of a document the host never sent
+//!     (an untitled one): `true`. It becomes the document's file; the next Save sends its name
+//!     with `false`. Names compare without case.
+//!   - Everything else is a copy or export that never becomes the document: `false` — rendered
+//!     images, SVG and PDF, `.fig` copies, and the variables exports (a `.variables.json`
+//!     sidecar's `.json` extension doesn't make it a document).
+//! - `figcraft:dirty` whenever unsaved changes appear or go away, `figcraft:failed` when the app
+//!   couldn't start.
+//!
+//! In host mode the app starts with no document (the home screen) and the host sends the file to
+//! edit; `?author=` names the user for comments and board notes.
+
+use std::cell::RefCell;
+use std::rc::Rc;
+
+use craft_web_host::web::{FileData, Host, Message};
+use figcraft_ui_egui::FigApp;
+
+/// The app id in the host messages (`figcraft:ready`).
+const APP: &str = "figcraft";
+
+/// The longest user name taken from `?author=`.
+const MAX_AUTHOR_CHARS: usize = 200;
+
+/// Files the host sent, on their way to the app's own open queue ([`figcraft_ui_egui::pending_open`]):
+/// `(name, bytes)`.
+pub type OpenQueue = Rc<RefCell<Vec<(String, Vec<u8>)>>>;
+
+#[derive(Clone)]
+pub struct Bridge {
+    host: Rc<Host>,
+    /// The file the host opened, and after a `saveAs` hand-over the document's file: the name a
+    /// Save under (`saveAs: false`) is decided against.
+    host_file: Rc<RefCell<Option<String>>>,
+}
+
+impl Bridge {
+    /// The bridge for this page, or `None` when FigCraft isn't hosted: no `?host=parent` and no
+    /// `data-host="page"` on the canvas, an unframed `?host=parent` page (it stays the normal app
+    /// with downloads), or a parent on another origin.
+    pub fn connect(canvas: &web_sys::HtmlCanvasElement) -> Option<Self> {
+        Some(Self { host: Rc::new(Host::connect(APP, canvas)?), host_file: Rc::default() })
+    }
+
+    /// Hear the files the host sends, and queue each one on `opens` for the app's own open path
+    /// (the shell drains it into [`figcraft_ui_egui::pending_open`] every frame, so a host file
+    /// opens like a dropped one).
+    pub fn listen(&self, opens: OpenQueue, ctx: egui::Context) {
+        let host_file = self.host_file.clone();
+        self.host.listen(move |message| {
+            if let Message::Open { name, data } = message {
+                deliver_open(&opens, &ctx, &host_file, &name, &data);
+            }
+        });
+    }
+
+    /// `?author=`: the host's name for the user signs comments and board notes.
+    pub fn set_author(app: &mut FigApp, author: &str) {
+        let author: String = author.trim().chars().take(MAX_AUTHOR_CHARS).collect();
+        if !author.is_empty() {
+            app.session.prefs.user_name = author;
+        }
+    }
+
+    pub fn post_ready(&self) {
+        let _ = self.host.post_ready(env!("CARGO_PKG_VERSION"), false);
+    }
+
+    /// The app couldn't start (no WebGPU or WebGL2, for example): let the host say so.
+    pub fn post_failed(&self, error: &str) {
+        let _ = self.host.post_failed(error, None);
+    }
+
+    /// The document file the host opened or the last Save As made, if any.
+    pub fn host_file(&self) -> Option<String> {
+        self.host_file.borrow().clone()
+    }
+
+    /// Hand a file the app would otherwise download to the host; `false` when nothing was
+    /// delivered. The `saveAs` rule is this module's documentation's.
+    pub fn post_save(&self, path: &str, bytes: &[u8]) -> bool {
+        let name = file_name(path);
+        let host_file = self.host_file.borrow().clone();
+        let save_as = crate::hostmode::save_as(&name, host_file.as_deref());
+        let sent = self.host.post_save(&name, bytes, None, save_as).is_ok();
+        // After a Save As hand-over the host has the new file: the next Save of it sends its name
+        // with `saveAs: false`. A failed send changes nothing, so a retry is still a Save As.
+        if sent && save_as {
+            *self.host_file.borrow_mut() = Some(name);
+        }
+        sent
+    }
+
+    /// Report unsaved changes when they appear or go away, not every frame (the crate does not
+    /// repeat a state it already reported).
+    pub fn set_dirty(&self, dirty: bool) {
+        self.host.post_dirty(dirty);
+    }
+}
+
+/// The file an open message carries, queued for the app's own open path, or nothing when the
+/// payload isn't one (a `File` the app doesn't read, or over the open limit).
+fn deliver_open(opens: &OpenQueue, ctx: &egui::Context, host_file: &RefCell<Option<String>>, name: &str, data: &FileData) {
+    let name = crate::hostmode::open_name(name);
+    let FileData::Bytes(array) = data else {
+        log::warn!("host file {name} came as a File; FigCraft reads bytes only; not opened");
+        return;
+    };
+    if figcraft_ui_egui::browser_can_read(&name, data.size()).is_err() {
+        log::warn!("host file {name} is too large to open in the browser; not opened");
+        return;
+    }
+    // The document's file is now the one the host sent: a Save of it under this name is
+    // `saveAs: false`.
+    *host_file.borrow_mut() = Some(name.clone());
+    opens.borrow_mut().push((name, array.to_vec()));
+    ctx.request_repaint();
+}
+
+/// The last component of `path`, or the whole of it when there is none.
+fn file_name(path: &str) -> String {
+    std::path::Path::new(path).file_name().map(|n| n.to_string_lossy().to_string()).unwrap_or_else(|| path.to_string())
+}

apps/figcraft-web/src/hostmode.rs

@@ -0,0 +1,92 @@
+//! Pure host-mode rules, shared by the bridge ([`crate::host`]) and testable without a browser
+//! (like [`crate::query`]): the name the bridge fills in when an open request has none, and whether
+//! a handed-over file becomes the document's file. Which pages host the app is `craft-web-host`'s.
+
+/// The file name used when an open request carries no usable one.
+pub const DEFAULT_OPEN_NAME: &str = "Untitled.figcraft";
+
+/// The extensions of files that can be a document's own file: the formats `file.save` and
+/// `file.saveAs` write (`file.open` opens both as native documents). A `.fig` file is an export
+/// copy instead, and so is everything else the app hands over (rendered images, SVG, PDF,
+/// variables).
+const DOC_EXTS: &[&str] = &["figcraft", "json"];
+
+/// The suffix `variable.export`'s downloads carry: a `.json` that is a variables sidecar, not a
+/// document, so its extension alone can't tell the `saveAs` decision.
+const VARIABLES_SIDECAR: &str = ".variables.json";
+
+/// The name `craft-web-host` gives an open request that carries no usable one (it cleans a host's
+/// name and falls back to this).
+const NAMELESS: &str = "document";
+
+/// A usable file name for an open request: the cleaned name the crate hands over, or
+/// [`DEFAULT_OPEN_NAME`] when the host sent none.
+pub fn open_name(name: &str) -> String {
+    if name == NAMELESS { DEFAULT_OPEN_NAME.to_string() } else { name.to_string() }
+}
+
+/// Whether the file `name` becomes the document's own file when handed over (`saveAs: true`),
+/// given the file the host opened (`None`: the host never sent one). The rule:
+///
+/// - A document file (`.figcraft` or `.json`, [`DOC_EXTS`]'s formats) under a name the host didn't
+///   open — Save As, or a Save of a document the host never sent — is the document's new file:
+///   `true`. Names compare without case.
+/// - A Save of the host's own file under its name is not: `false`.
+/// - Everything else is a copy or export that never becomes the document — rendered images, SVG,
+///   PDF, `.fig` copies, variables — and the variables sidecar counts as one whatever its `.json`
+///   extension says: `false`.
+pub fn save_as(name: &str, host_file: Option<&str>) -> bool {
+    if name.to_ascii_lowercase().ends_with(VARIABLES_SIDECAR) {
+        return false;
+    }
+    let ext = std::path::Path::new(name).extension().and_then(std::ffi::OsStr::to_str);
+    if !ext.is_some_and(|e| DOC_EXTS.iter().any(|x| x.eq_ignore_ascii_case(e))) {
+        return false;
+    }
+    match host_file {
+        Some(host) => !host.eq_ignore_ascii_case(name),
+        None => true,
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn open_names_fall_back_to_the_default_when_the_host_sent_none() {
+        assert_eq!(open_name("Poster.figcraft"), "Poster.figcraft");
+        assert_eq!(open_name("Poster 2.json"), "Poster 2.json");
+        assert_eq!(open_name("document"), DEFAULT_OPEN_NAME, "what the crate says for a missing or blank name");
+    }
+
+    #[test]
+    fn a_save_of_the_host_s_file_is_not_save_as() {
+        assert!(!save_as("Poster.figcraft", Some("Poster.figcraft")));
+        assert!(!save_as("poster.FIGCRAFT", Some("Poster.figcraft")), "names compare without case");
+        assert!(!save_as("design.json", Some("design.json")));
+    }
+
+    #[test]
+    fn a_new_document_file_is_save_as() {
+        assert!(save_as("Poster 2.figcraft", Some("Poster.figcraft")));
+        assert!(save_as("Poster.json", Some("Poster.figcraft")), "the other format a document's file takes");
+        assert!(save_as("Untitled.figcraft", None), "the host never sent a file");
+        assert!(save_as("Poster.figcraft", Some("design.json")), "the opened .json saved as .figcraft is a new file");
+    }
+
+    #[test]
+    fn copies_and_exports_never_become_the_document_s_file() {
+        for name in ["Poster.png", "Poster@2x.jpg", "Poster.svg", "Poster.pdf", "Poster.fig", "Poster.csv", "Poster.variables.css"] {
+            assert!(!save_as(name, Some("Poster.figcraft")), "{name} is a copy");
+            assert!(!save_as(name, None), "{name} is a copy even without a host file");
+        }
+    }
+
+    #[test]
+    fn the_variables_sidecar_is_a_copy_whatever_its_extension() {
+        assert!(!save_as("Poster.variables.json", Some("Poster.figcraft")));
+        assert!(!save_as("Poster.variables.json", None));
+        assert!(!save_as("design.variables.json", Some("design.variables.json")));
+    }
+}

apps/figcraft-web/src/main.rs

@@ -19,9 +19,17 @@
 //!   server…), but can't host a session. A page served over `https://` reaches only `wss://`
 //!   servers and the same computer (browsers block `ws://` from secure pages); serve it over
 //!   `http://` on a trusted network to reach plain `ws://` hosts on other machines.
+//! - host mode: `?host=parent` (a same-origin page embedding FigCraft in an `<iframe>`) or
+//!   `data-host="page"` on the canvas (the page's own document) hands the page the app's files
+//!   instead of downloading them and reports unsaved changes (`host`);
+//! - live sessions: it joins sessions a desktop app hosts (File ▸ Join live session…) but can't
+//!   host one. A page served over `https://` can only reach sessions on the same computer
 //!
 //! URL query flags: `?webgl` forces the WebGL2 backend instead of WebGPU; `?control` installs
-//! `window.figcraft`, the page's control channel (`api.rs`), which is off without it.
+//! `window.figcraft`, the page's control channel (`api.rs`), which is off without it; `?host=parent`
+//! (inside an `<iframe>`) talks to a same-origin parent page instead: it sends the document to open
+//! and stores what FigCraft saves. `&author=` names the user for comments and board notes in either
+//! host mode.
 //!
 //! URL fragment: `#join=<invite link or join code>` joins that live session once the page has
 //! loaded, so a bookmark opens a shared file. `join` takes the rest of the fragment: put it last.
@@ -30,6 +38,10 @@
 
 #[cfg(target_arch = "wasm32")]
 mod api;
+#[cfg(target_arch = "wasm32")]
+mod host;
+#[cfg(any(target_arch = "wasm32", test))]
+mod hostmode;
 #[cfg(any(target_arch = "wasm32", test))]
 mod kept;
 #[cfg(target_arch = "wasm32")]

apps/figcraft-web/src/web.rs

@@ -32,6 +32,15 @@ pub fn start() {
             log::error!("missing <canvas id=\"{CANVAS_ID}\">");
             return;
         };
+        // Host modes (`craft-web-host`): `?host=parent`, a same-origin page framing FigCraft, opens
+        // documents in it and stores what it saves (`host`); unframed there is no parent, so that URL
+        // on its own stays the normal app with downloads. `data-host="page"` on the canvas opts a
+        // page in instead: it runs FigCraft in its own document and talks over DOM `CustomEvent`s on
+        // the canvas.
+        let bridge = crate::host::Bridge::connect(&canvas);
+        let app_bridge = bridge.clone();
+        // Files the host sends, on their way into the app's own open queue each frame.
+        let opens: crate::host::OpenQueue = std::rc::Rc::default();
         let mut options = eframe::WebOptions::default();
         // `?webgl`: force the WebGL2 backend (troubleshooting, and headless browsers whose WebGPU
         // adapter request returns nothing).
@@ -44,12 +53,15 @@ pub fn start() {
             .start(
                 canvas,
                 options,
-                Box::new(|cc| {
+                Box::new(move |cc| {
                     if let Some(rs) = &cc.wgpu_render_state {
                         log::info!("figcraft-web: wgpu backend {:?}", rs.adapter.get_info().backend);
                     }
                     let reduce_motion = web_sys::window().and_then(|w| w.match_media("(prefers-reduced-motion: reduce)").ok().flatten());
-                    let mut session = Session::new();
+                    // Host mode: the host sends the file to edit, so start with no document (the
+                    // home screen), as the desktop app does without a file; otherwise the session
+                    // starts with one new document.
+                    let mut session = if app_bridge.is_some() { Session::empty() } else { Session::new() };
                     // The host names its own server: the default for sharing, codes and the team list.
                     if let Some(server) = page_meta("figcraft-server").as_deref().and_then(crate::query::page_server) {
                         session.prefs.publish_server = server;
@@ -60,11 +72,18 @@ pub fn start() {
                     // whatever arrives on the socket wakes the page for a frame.
                     let ctx = cc.egui_ctx.clone();
                     session.live.install(Box::new(figcraft_collab_net::NetLink::new(std::sync::Arc::new(move || ctx.request_repaint()))));
-                    let mut fig = FigApp::new(session, Box::new(WebServices { reduce_motion, ctx: cc.egui_ctx.clone() }));
+                    let mut fig = FigApp::new(session, Box::new(WebServices { reduce_motion, ctx: cc.egui_ctx.clone(), host: app_bridge.clone() }));
                     fig.note_recovered(recovered);
                     if let Err(e) = crate::pasted::install(cc.egui_ctx.clone()) {
                         log::error!("couldn't listen for pasted images: {e:?}");
                     }
+                    // `?author=`: the host's name for the user signs this visit's comments and board
+                    // notes (nothing is stored in the browser, so nothing needs keeping).
+                    if app_bridge.is_some()
+                        && let Some(author) = query_param("author")
+                    {
+                        crate::host::Bridge::set_author(&mut fig, &author);
+                    }
                     // `#join=<link>`: join that session, as opening an invite link does on the desktop.
                     let hash = web_sys::window().and_then(|w| w.location().hash().ok()).unwrap_or_default();
                     if let Some(link) = crate::query::join_link(&hash) {
@@ -78,10 +97,21 @@ pub fn start() {
                             log::error!("couldn't install window.figcraft: {e:?}");
                         }
                     }
-                    Ok(Box::new(WebShell { fig }))
+                    // The host's files arrive on the app's own open path (a dropped file's).
+                    if let Some(bridge) = &app_bridge {
+                        bridge.listen(opens.clone(), cc.egui_ctx.clone());
+                    }
+                    Ok(Box::new(WebShell { fig, host: app_bridge, opens }))
                 }),
             )
             .await;
+        // Ready only once the runner is up: starting can still fail after the app is made.
+        if let Some(bridge) = &bridge {
+            match &result {
+                Ok(()) => bridge.post_ready(),
+                Err(e) => bridge.post_failed(&format!("{e:?}")),
+            }
+        }
         if let Some(el) = document.get_element_by_id(LOADING_ID) {
             match result {
                 Ok(()) => el.remove(),
@@ -141,20 +171,45 @@ fn query() -> String {
     web_sys::window().and_then(|w| w.location().search().ok()).unwrap_or_default()
 }
 
+fn query_param(key: &str) -> Option<String> {
+    web_sys::UrlSearchParams::new_with_str(&query()).ok()?.get(key)
+}
+
 struct WebShell {
     fig: FigApp,
+    /// The host bridge, when the page hosts the app (`?host=parent` or `data-host="page"`).
+    host: Option<crate::host::Bridge>,
+    /// Files the host sent, waiting to join the app's own open queue.
+    opens: crate::host::OpenQueue,
 }
 
 impl eframe::App for WebShell {
     // eframe runs `logic` for visible tabs and, with only `run_logic`, for hidden ones: keep
     // autosave/live/control deadlines moving without a paint. `FigApp::ui` does not repeat it.
-    /// Run the browser shell's eframe logic callback: guard `background_tick` so hidden tabs
-    /// still advance autosave, live and control deadlines without painting. `FigApp::ui` does
+    /// Run the browser shell's eframe logic callback: hand the host's files to the app's open
+    /// queue, guard `background_tick` so hidden tabs still advance autosave, live and control
+    /// deadlines without painting, and report unsaved changes to the host. `FigApp::ui` does
     /// not repeat it.
     fn logic(&mut self, ctx: &egui::Context, _frame: &mut eframe::Frame) {
         // Every frame, hidden or not, starts here: what the last one left is what a panic keeps.
         UNSAVED.with(|u| u.try_borrow_mut().map(|mut u| u.follow(&self.fig.session))).ok();
+        // Files the host sent join the app's own open queue (a dropped file's): the same
+        // "Opening as a new file" card, and `file.open` with the contents once read.
+        for (name, bytes) in std::mem::take(&mut *self.opens.borrow_mut()) {
+            let read: figcraft_ui_egui::ReadFuture = Box::pin(std::future::ready(Ok(bytes)));
+            self.fig.ui.pending_opens.push(figcraft_ui_egui::pending_open::PendingOpen {
+                label: name.clone(),
+                params: serde_json::json!({ "name": name }),
+                command: "file.open",
+                target: None,
+                read: Some(read),
+            });
+        }
         figcraft_ui_egui::windows::guard(&mut self.fig, ctx, |fig| fig.background_tick(ctx));
+        // The host hears when unsaved changes appear or go away (crate::host).
+        if let Some(bridge) = &self.host {
+            bridge.set_dirty(self.fig.session.docs.iter().any(|d| d.is_dirty()));
+        }
     }
 
     fn raw_input_hook(&mut self, ctx: &egui::Context, raw_input: &mut egui::RawInput) {
@@ -182,12 +237,15 @@ impl eframe::App for WebShell {
 
 /// Browser services. Files are opened and imported through the browser's file picker, which hands
 /// over their contents (pickers that need a path return nothing, the trait's defaults); files are
-/// saved as downloads. Copies go to the system clipboard through egui's output; pastes arrive as
-/// paste events with their text or image (a page can't read the clipboard when it likes).
+/// saved as downloads, or handed to the host page in host mode. Copies go to the system clipboard
+/// through egui's output; pastes arrive as paste events with their text or image (a page can't
+/// read the clipboard when it likes).
 struct WebServices {
     /// `prefers-reduced-motion: reduce` (it follows the setting while the page is open).
     reduce_motion: Option<web_sys::MediaQueryList>,
     ctx: egui::Context,
+    /// The host bridge in host mode: files are handed over instead of downloaded ([`crate::host`]).
+    host: Option<crate::host::Bridge>,
 }
 
 impl Services for WebServices {
@@ -204,11 +262,15 @@ impl Services for WebServices {
     fn downloads(&self) -> bool {
         true
     }
-    /// A Blob behind a temporary `<a download>` link, clicked and removed.
+    /// A Blob behind a temporary `<a download>` link, clicked and removed; in host mode the file
+    /// goes to the host page instead ([`crate::host`]).
     fn download(&mut self, name: &str, bytes: &[u8]) -> bool {
         if crate::api::capture(name, bytes) {
             return true;
         }
+        if let Some(bridge) = &self.host {
+            return bridge.post_save(name, bytes);
+        }
         match download(name, bytes) {
             Ok(()) => true,
             Err(e) => {
@@ -217,6 +279,9 @@ impl Services for WebServices {
             }
         }
     }
+    fn host_file(&self) -> Option<String> {
+        self.host.as_ref()?.host_file()
+    }
     fn clipboard_set_text(&mut self, s: &str) {
         figcraft_ui_egui::egui_copy_text(&self.ctx, s);
     }

contributors/people.toml

@@ -101,3 +101,6 @@ sync_github_name = true
 
 [people.aleksei-suholita]
 real_name = "Oleksii Sukholita"
+
+[people.helenkwok]
+real_name = "Helen Kwok"

crates/collab/src/change.rs

@@ -333,6 +333,17 @@ impl Change {
 }
 
 impl Entry {
+    /// The synced list this entry belongs to (`None` for entries kept in maps).
+    pub(crate) fn family(&self) -> Option<Family> {
+        match self {
+            Entry::Style(_) => Some(Family::Styles),
+            Entry::Comment(_) => Some(Family::Comments),
+            Entry::Collection(_) => Some(Family::Collections),
+            Entry::Variable(_) => Some(Family::Variables),
+            Entry::DevSnapshot(_) | Entry::Image(_) | Entry::Ballot(_) => None,
+        }
+    }
+
     /// The client id space the entry's id lies in ([`figcraft_doc::ids`]): ids made during a live
     /// session carry their creator's client id, ids from before and ids of other forms are in
     /// space 0. `None` for entries keyed by something else (dev snapshots by layer, images by

crates/collab/src/diff.rs

@@ -95,7 +95,8 @@ pub fn diff(from: &Replica, to: &Document) -> Result<Diff, Error> {
     let mut changes = fields;
     let new: BTreeSet<NodeId> = added.iter().copied().collect();
     // Creations, parents before children.
-    added.sort_by_cached_key(|id| (depth(to, *id), *id));
+    let mut memo = BTreeMap::new();
+    added.sort_by_cached_key(|id| (depth(to, *id, &mut memo), *id));
     for id in &added {
         if let Some(n) = to.node(*id) {
             changes.push(create_change(n, replica.key(*id))?);
@@ -121,18 +122,30 @@ pub fn diff(from: &Replica, to: &Document) -> Result<Diff, Error> {
     Ok(Diff { changes, replica })
 }
 
-/// Depth of `id` in `doc` (pages are 0).
-fn depth(doc: &Document, id: NodeId) -> usize {
-    let mut d = 0;
+/// Depth of `id` in `doc` (pages are 0). `memo` holds the depths found so far, so a deep chain of
+/// new layers is walked once rather than once per layer.
+fn depth(doc: &Document, id: NodeId, memo: &mut BTreeMap<NodeId, usize>) -> usize {
+    let mut chain = vec![id];
+    let mut base = 0;
     let mut cur = doc.node(id).and_then(|n| n.parent);
     while let Some(p) = cur {
-        d += 1;
-        if d > 100_000 {
+        if let Some(d) = memo.get(&p) {
+            base = *d + 1;
             break;
         }
+        // An acyclic chain is no longer than the document: this only stops a cycle.
+        if chain.len() > doc.node_count() {
+            break;
+        }
+        chain.push(p);
         cur = doc.node(p).and_then(|n| n.parent);
     }
-    d
+    // `chain` runs from `id` up; the last entry's depth is `base` when it ends at a root or a memo hit.
+    let top = chain.len();
+    for (i, c) in chain.iter().enumerate() {
+        memo.insert(*c, base + (top - 1 - i));
+    }
+    memo.get(&id).copied().unwrap_or(0)
 }
 
 /// New keys for the children `kids` (in their new order) whose `old` key no longer fits: the
@@ -196,3 +209,21 @@ fn increasing_run(keys: &[Option<&str>]) -> Vec<bool> {
     }
     kept
 }
+
+#[cfg(test)]
+mod depth_tests {
+    use super::*;
+    use figcraft_doc::NodeKind;
+
+    #[test]
+    fn a_chain_longer_than_a_fixed_bound_is_walked_whole() {
+        let mut doc = Document::new("File");
+        let mut parent = doc.first_page().unwrap();
+        let mut last = parent;
+        for i in 0..100_050 {
+            last = doc.create(parent, NodeKind::Frame, &format!("F{i}"), 0.0, 0.0, 1.0, 1.0).unwrap();
+            parent = last;
+        }
+        assert_eq!(depth(&doc, last, &mut BTreeMap::new()), 100_050);
+    }
+}

crates/collab/src/diff_tests.rs

@@ -310,3 +310,14 @@ fn many_sibling_placements_keep_the_order_of_counting_them() {
         assert_eq!(r.document().node(p).unwrap().children, kids[&p], "children of {p}");
     }
 }
+
+#[test]
+fn a_chain_of_new_nested_layers_is_created_parents_first() {
+    let (a, _, frame, _) = setup();
+    let mut b = a.document().clone();
+    let mut parent = frame;
+    for i in 0..400 {
+        parent = b.create(parent, NodeKind::Frame, &format!("F{i}"), 0.0, 0.0, 10.0, 10.0).unwrap();
+    }
+    assert_eq!(round_trip(&a, &b).iter().filter(|c| matches!(c, Change::Create { .. })).count(), 400);
+}

crates/collab/src/replica.rs

@@ -236,7 +236,9 @@ impl Replica {
                         self.doc.insert_page(node).map_err(doc_err)?;
                     }
                     (false, Some(p)) => {
-                        let at = self.slot(&self.doc.get(*p).map_err(doc_err)?.children, *id, position);
+                        // A new id sits in no sibling list yet: no scan for it, just the binary search.
+                        let siblings = &self.doc.get(*p).map_err(doc_err)?.children;
+                        let at = siblings.partition_point(|c| (self.key(*c), *c) < (position.as_str(), *id));
                         self.doc.insert(node, *p, Some(at)).map_err(doc_err)?;
                     }
                     _ => return Err(Error::Invalid("pages, and only pages, have no parent".into())),

crates/collab/src/server.rs

@@ -6,7 +6,7 @@ use std::collections::{BTreeMap, BTreeSet, VecDeque};
 use figcraft_doc::{Document, NodeId};
 use serde::{Deserialize, Serialize};
 
-use crate::change::{Change, Entry, Prop, Target};
+use crate::change::{Change, Entry, Family, Prop, Target};
 use crate::message::{
     Accepted, Access, CatchUp, ClientMsg, Hello, PROTOCOL, Peer, Presence, Processed, Resume, ServerMsg, Signal, reads_comments, reads_signals,
 };
@@ -413,10 +413,14 @@ impl Server {
             // client learned what happened to it from the catch-up.
             ClientMsg::Changes { batch_id, .. } if self.issued.get(&from).is_some_and(|p| batch_id <= p.last_batch) => Vec::new(),
             ClientMsg::Changes { base_seq, batch_id, changes } => {
+                let mut denied = true;
                 let result = match self.limited.get(&from) {
                     Some(Access::View) => Err(Error::Invalid(VIEW_ONLY.into())),
                     Some(Access::Comment) if !changes.iter().all(Change::is_comment) => Err(Error::Invalid(COMMENT_ONLY.into())),
-                    _ => self.accept(from, base_seq, &changes),
+                    _ => {
+                        denied = false;
+                        self.accept(from, base_seq, &changes)
+                    }
                 };
                 if let Some(p) = self.issued.get_mut(&from) {
                     p.note(batch_id, result.is_err());
@@ -430,7 +434,9 @@ impl Server {
                     }
                     Err(e) => {
                         self.note(Journal::Refused { client: from, batch_id });
-                        let fixes = self.fixes(&changes).unwrap_or_default();
+                        // A refusal for lack of permission costs no repair: the client's confirmed copy
+                        // already is the server's state, so the fixes would only repeat it.
+                        let fixes = if denied { Vec::new() } else { self.fixes(&changes).unwrap_or_default() };
                         vec![Outgoing::To(from, ServerMsg::Reject { batch_id, reason: reason(&e), fixes })]
                     }
                 }
@@ -557,6 +563,7 @@ impl Server {
     fn check_entries(&self, from: u32, changes: &[Change], after: &Document) -> Result<Vec<(Entry, bool)>, Error> {
         let before = self.state.document();
         let mut touched: BTreeSet<Entry> = BTreeSet::new();
+        let mut listed: BTreeMap<Family, (BTreeSet<Entry>, BTreeSet<Entry>)> = BTreeMap::new();
         for c in changes {
             match c {
                 Change::Put { entry, .. } | Change::Remove { entry } if entry.id_space().is_some() => {
@@ -565,8 +572,10 @@ impl Server {
                 // A whole list replaced (the fallback for lists whose ids aren't unique).
                 Change::SetDoc { prop, .. } => {
                     if let Some(Ok(family)) = prop.list() {
-                        touched.extend(docprops::entries(before, family));
-                        touched.extend(docprops::entries(after, family));
+                        let (b, a) = (docprops::entries(before, family), docprops::entries(after, family));
+                        touched.extend(b.iter().chain(&a).cloned());
+                        // Looked up in sets below: a linear search per entry would be quadratic.
+                        listed.entry(family).or_insert_with(|| (b.into_iter().collect(), a.into_iter().collect()));
                     }
                 }
                 _ => {}
@@ -574,7 +583,10 @@ impl Server {
         }
         let mut out = Vec::new();
         for entry in touched {
-            let (was, now) = (docprops::has(before, &entry), docprops::has(after, &entry));
+            let (was, now) = match entry.family().and_then(|f| listed.get(&f)) {
+                Some((b, a)) => (b.contains(&entry), a.contains(&entry)),
+                None => (docprops::has(before, &entry), docprops::has(after, &entry)),
+            };
             if was == now {
                 continue;
             }

crates/collab/src/server_tests.rs

@@ -182,6 +182,26 @@ fn deleted_nodes_can_come_back_but_ids_are_never_handed_out_twice() {
     assert_eq!(s.document(), gone.document());
 }
 
+#[test]
+fn a_viewers_refused_deletion_gets_no_repair() {
+    let (d, _, frame) = doc();
+    let mut s = Server::new(d, "tok", Limits::default());
+    let (id, out) = s.join_as(hello("tok"), crate::message::Access::View).unwrap();
+    let Some(Outgoing::To(_, welcome)) = out.into_iter().next() else { panic!() };
+    let mut v = Client::join(welcome).unwrap();
+    let del = edit(&mut v, |d| d.remove(frame).unwrap());
+    let (reason, fixes) = rejected(
+        &mut s,
+        id,
+        match del {
+            ClientMsg::Changes { changes, .. } => changes,
+            _ => panic!(),
+        },
+    );
+    assert_eq!(reason, crate::VIEW_ONLY);
+    assert!(fixes.is_empty(), "{fixes:?}");
+}
+
 #[test]
 fn fixes_roll_a_rejected_client_back_to_the_server_state() {
     let (d, _, frame) = doc();

crates/doc/src/effects_tests.rs

@@ -49,6 +49,47 @@ fn glass_values_are_clamped_and_reach_their_backdrop() {
     assert_eq!(hidden.backdrop_radius(), 0.0);
 }
 
+#[test]
+fn glass_frost_stays_within_the_reference_range() {
+    // A file from before the 0–100 range draws its frost at 100, and reaches no further.
+    let g = Glass { frost: 150.0, ..Glass::default() };
+    assert_eq!(g.sanitized().frost, Glass::MAX_FROST);
+    let e = Effect { kind: EffectKind::Glass(g), visible: true };
+    let capped = Effect { kind: EffectKind::Glass(Glass { frost: Glass::MAX_FROST, ..Glass::default() }), visible: true };
+    assert_eq!(e.backdrop_radius(), capped.backdrop_radius());
+}
+
+#[test]
+fn glass_fields_take_bound_numbers_as_the_panel_shows_them() {
+    let mut g = Glass::default();
+    for (field, x) in [
+        ("lightAngle", 30.0),
+        ("lightIntensity", 25.0),
+        ("refraction", 40.0),
+        ("depth", 12.0),
+        ("dispersion", 10.0),
+        ("radius", 8.0),
+        ("splay", 50.0),
+    ] {
+        assert!(g.set_bound(field, x), "{field}");
+    }
+    assert_eq!((g.light_angle, g.light_intensity, g.refraction, g.depth, g.dispersion, g.frost, g.splay), (30.0, 0.25, 0.4, 12.0, 0.1, 8.0, 0.5));
+    // Out of range: clamped to the field's range.
+    for (field, x) in [("lightAngle", 270.0), ("lightIntensity", 250.0), ("depth", 0.0), ("radius", 150.0), ("splay", -5.0)] {
+        assert!(g.set_bound(field, x), "{field}");
+    }
+    assert_eq!((g.light_angle, g.light_intensity, g.depth, g.frost, g.splay), (180.0, 1.0, 1.0, Glass::MAX_FROST, 0.0));
+    // A field glass doesn't have, or a value that isn't a number, changes nothing.
+    let before = g.clone();
+    assert!(!g.set_bound("spread", 3.0));
+    assert!(!g.set_bound("splay", f64::NAN));
+    assert!(!g.set_bound("depth", f64::INFINITY));
+    assert_eq!(g, before);
+    for field in Glass::BOUND_FIELDS {
+        assert!(Glass::default().set_bound(field, 1.0), "{field}");
+    }
+}
+
 #[test]
 fn effect_colours() {
     let mut e = Effect::noise();

crates/doc/src/lib.rs

@@ -574,6 +574,19 @@ impl Document {
         Ok(())
     }
 
+    /// Remove every child of `id` with its subtree, in one pass over `id`'s child list (removing
+    /// them one by one would search that list once per child).
+    pub fn remove_children(&mut self, id: NodeId) -> DocResult<()> {
+        let kids = std::mem::take(&mut self.get_mut(id)?.children);
+        for c in kids {
+            for d in self.subtree(c) {
+                self.nodes.remove(&d);
+                self.dirty.touch(d);
+            }
+        }
+        Ok(())
+    }
+
     /// Whether sections may go in `parent`: a page or another section (never a frame or a group).
     pub fn takes_sections(&self, parent: NodeId) -> bool {
         self.node(parent).is_some_and(|p| p.is_page() || matches!(p.kind, NodeKind::Section { .. }))
@@ -1085,6 +1098,9 @@ impl Document {
         // lookups: a wide parent or a long page list doesn't make validation quadratic.
         let edges: std::collections::BTreeSet<(NodeId, NodeId)> = self.nodes.iter().flat_map(|(p, n)| n.children.iter().map(|c| (*p, *c))).collect();
         let page_ids: std::collections::BTreeSet<NodeId> = self.pages.iter().copied().collect();
+        if page_ids.len() != self.pages.len() {
+            note(&mut issues, || "a page is listed twice".to_string());
+        }
         for (id, n) in self.nodes.iter() {
             if n.id != *id {
                 note(&mut issues, || format!("node key {id} has id {}", n.id));
@@ -1178,9 +1194,10 @@ impl Document {
         if store != self.libraries.store {
             Arc::make_mut(&mut self.libraries).store = store;
         }
-        self.pages.retain(|p| self.nodes.get(p).is_some_and(|n| n.is_page()) && Some(*p) != store);
+        // A page listed twice would be imported, exported and walked once per listing.
+        let mut listed = std::collections::BTreeSet::new();
+        self.pages.retain(|p| self.nodes.get(p).is_some_and(|n| n.is_page()) && Some(*p) != store && listed.insert(*p));
         // Unlisted pages join the list; a set keeps many pages from making this quadratic (#1078).
-        let mut listed: std::collections::BTreeSet<NodeId> = self.pages.iter().copied().collect();
         for (k, n) in self.nodes.iter() {
             if n.is_page() && Some(*k) != store && listed.insert(*k) {
                 self.pages.push(*k);

crates/doc/src/props.rs

@@ -660,7 +660,7 @@ pub struct Glass {
     pub depth: f64,
     /// Colour splitting along the curved edge (0–1).
     pub dispersion: f64,
-    /// Blur of the backdrop (a blur radius, document units).
+    /// Blur of the backdrop (a blur radius, document units, 0–[`Self::MAX_FROST`]).
     pub frost: f64,
     /// How widely the light spreads over the glass (0–1).
     pub splay: f64,
@@ -673,6 +673,34 @@ impl Default for Glass {
 }
 
 impl Glass {
+    /// The most frost a glass takes, as the reference tool's Frost field (0–100).
+    pub const MAX_FROST: f64 = 100.0;
+
+    /// The fields a variable binds on a glass effect (`effects/<i>/<field>`), see [`Self::set_bound`].
+    pub const BOUND_FIELDS: [&'static str; 7] = ["lightAngle", "lightIntensity", "refraction", "depth", "dispersion", "radius", "splay"];
+
+    /// Sets `field` (one of [`Self::BOUND_FIELDS`]) from a bound number variable, read as the
+    /// Design panel's field shows it: intensity, refraction, dispersion and splay in percent, the
+    /// frost as `radius`, each clamped to the field's range. False for a field glass doesn't have
+    /// or a value that isn't finite (nothing changes).
+    pub fn set_bound(&mut self, field: &str, x: f64) -> bool {
+        if !x.is_finite() {
+            return false;
+        }
+        let pct = (x / 100.0).clamp(0.0, 1.0);
+        match field {
+            "lightAngle" => self.light_angle = x.clamp(-180.0, 180.0),
+            "lightIntensity" => self.light_intensity = pct,
+            "refraction" => self.refraction = pct,
+            "depth" => self.depth = x.clamp(1.0, 1000.0),
+            "dispersion" => self.dispersion = pct,
+            "radius" => self.frost = x.clamp(0.0, Self::MAX_FROST),
+            "splay" => self.splay = pct,
+            _ => return false,
+        }
+        true
+    }
+
     /// The values clamped to their ranges (non-finite ones at their defaults).
     pub fn sanitized(&self) -> Glass {
         let d = Glass::default();
@@ -683,15 +711,23 @@ impl Glass {
             refraction: ok(self.refraction, d.refraction, 0.0, 1.0),
             depth: ok(self.depth, d.depth, 1.0, 1000.0),
             dispersion: ok(self.dispersion, d.dispersion, 0.0, 1.0),
-            frost: ok(self.frost, d.frost, 0.0, 1000.0),
+            frost: ok(self.frost, d.frost, 0.0, Self::MAX_FROST),
             splay: ok(self.splay, d.splay, 0.0, 1.0),
         }
     }
 
-    /// Furthest the curved edge moves the backdrop (document units).
+    /// How far `dispersion` splits the colour channels, as a share of the bend: at full dispersion
+    /// red moves up to this much further and blue as much less. Matched to the reference tool:
+    /// across a black-to-white edge in the bend, red and blue part about 4.7 px at 100% and 2.4 px
+    /// at 50% (at 2×, depth 20, refraction 80%).
+    pub const DISPERSION_SPREAD: f64 = 0.16;
+
+    /// Furthest the curved edge moves the backdrop (document units): at most `depth` × `refraction`
+    /// (all of it a bevel in from the edge), and red's dispersion steps up to
+    /// [`Self::DISPERSION_SPREAD`] × `dispersion` times that again.
     pub fn max_bend(&self) -> f64 {
         let g = self.sanitized();
-        g.refraction * g.depth * (1.0 + g.dispersion * 0.25)
+        g.refraction * g.depth * (1.0 + Self::DISPERSION_SPREAD * g.dispersion)
     }
 }
 

crates/doc/src/proto_expr.rs

@@ -12,6 +12,8 @@ use crate::{CollectionId, ModeId, VariableValue, Variables};
 pub const MAX_EXPR_DEPTH: usize = 32;
 /// Longest string an expression builds (characters).
 const MAX_STRING: usize = 10_000;
+/// The most string bytes one operation's operands may hold together (generous: results cap at `MAX_STRING`).
+const MAX_OPERAND_BYTES: usize = 1 << 20;
 
 /// An expression over variables.
 #[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
@@ -115,7 +117,19 @@ impl Expr {
             }
             Expr::Op { op, args } => (*op, args),
         };
-        let vals: Vec<VariableValue> = args.iter().map(|a| a.eval_at(vars, modes, depth + 1)).collect::<Option<_>>()?;
+        // Retained operands are bounded by bytes, so repeated references to one long string can't multiply it.
+        let mut text_bytes = 0usize;
+        let mut vals = Vec::with_capacity(args.len());
+        for a in args {
+            let v = a.eval_at(vars, modes, depth + 1)?;
+            if let VariableValue::String(s) = &v {
+                text_bytes = text_bytes.saturating_add(s.len());
+                if text_bytes > MAX_OPERAND_BYTES {
+                    return None;
+                }
+            }
+            vals.push(v);
+        }
         apply(op, &vals)
     }
 
@@ -259,10 +273,18 @@ fn apply(op: ExprOp, vals: &[VariableValue]) -> Option<VariableValue> {
     match op {
         Add if vals.iter().any(|v| matches!(v, VariableValue::String(_))) => {
             let mut s = String::new();
+            let mut chars = 0;
             for v in vals {
-                s.push_str(&as_text(v)?);
+                // Every operand is checked (a colour makes the whole expression None); only the
+                // characters it adds are counted, and appending stops at the cap.
+                let t = as_text(v)?;
+                if chars < MAX_STRING {
+                    let before = s.len();
+                    s.extend(t.chars().take(MAX_STRING - chars));
+                    chars += s[before..].chars().count();
+                }
             }
-            Some(VariableValue::String(s.chars().take(MAX_STRING).collect()))
+            Some(VariableValue::String(s))
         }
         Add => fold(|a, b| Some(a + b)),
         Subtract => fold(|a, b| Some(a - b)),

crates/doc/src/proto_expr_tests.rs

@@ -124,6 +124,13 @@ fn deep_and_hostile_expressions_are_bounded() {
     let joined = Expr::op(ExprOp::Add, vec![s(&long), s(&long)]);
     let Some(VariableValue::String(t)) = eval(&joined) else { panic!() };
     assert_eq!(t.chars().count(), 10_000, "capped");
+    // Past the cap a colour operand still fails the expression, and empty operands add nothing.
+    let color = Expr::Value(VariableValue::Color(Color::BLACK));
+    let mut ops = vec![s(&"x".repeat(10_000))];
+    ops.extend((0..50).map(|_| s("")));
+    assert!(matches!(eval(&Expr::op(ExprOp::Add, ops.clone())), Some(VariableValue::String(t)) if t.chars().count() == 10_000));
+    ops.push(color);
+    assert_eq!(eval(&Expr::op(ExprOp::Add, ops)), None, "a colour past the cap is still a type error");
 }
 
 fn nav(id: u64) -> Action {
@@ -199,3 +206,12 @@ fn serde_round_trip_and_old_files() {
     let old: Action = serde_json::from_str(r#"{"type":"setVariable","variable":"n","value":2}"#).unwrap_or(Action::Back);
     assert_eq!(old, Action::SetVariable { variable: "n".into(), value: serde_json::json!(2), expr: None });
 }
+
+#[test]
+fn operands_holding_too_many_string_bytes_are_refused() {
+    let long = "x".repeat(300_000);
+    let few = Expr::op(ExprOp::Add, vec![s(&long), s(&long)]);
+    assert!(eval(&few).is_some());
+    let many = Expr::op(ExprOp::Add, (0..8).map(|_| s(&long)).collect());
+    assert_eq!(eval(&many), None);
+}

crates/doc/src/tests.rs

@@ -348,6 +348,20 @@ fn repair_drops_cycles_and_repeated_children() {
     assert_eq!(bad.subtree(p), vec![p, r]);
 }
 
+#[test]
+fn repair_lists_a_page_once_however_often_the_file_lists_it() {
+    let mut d = Document::new("x");
+    let p = page(&d);
+    let q = d.add_page("Two");
+    let mut v = serde_json::to_value(&d).unwrap();
+    v["pages"] = serde_json::json!([p, q, p, q, p]);
+    let mut bad: Document = serde_json::from_value(v).unwrap();
+    assert!(bad.validate().iter().any(|i| i.contains("listed twice")), "{:?}", bad.validate());
+    bad.repair();
+    assert!(bad.validate().is_empty(), "{:?}", bad.validate());
+    assert_eq!(bad.pages, vec![p, q]);
+}
+
 #[test]
 fn validate_caps_the_issue_list() {
     let mut d = Document::new("x");
@@ -846,3 +860,17 @@ fn the_colour_walker_visits_calculation_literals() {
     let ColorOperand::Literal { literal } = from else { panic!("literal operand") };
     assert_eq!(literal.a, 0.5, "the mix's stored literal was converted like every other colour");
 }
+
+#[test]
+fn remove_children_removes_every_subtree_and_keeps_the_parent() {
+    let mut doc = Document::new("T");
+    let page = doc.first_page().unwrap();
+    let frame = doc.create(page, NodeKind::Frame, "F", 0.0, 0.0, 100.0, 100.0).unwrap();
+    let inner = doc.create(frame, NodeKind::Frame, "Inner", 0.0, 0.0, 10.0, 10.0).unwrap();
+    let leaf = doc.create(inner, NodeKind::Rectangle, "Leaf", 0.0, 0.0, 5.0, 5.0).unwrap();
+    let other = doc.create(page, NodeKind::Rectangle, "Other", 0.0, 0.0, 5.0, 5.0).unwrap();
+    doc.remove_children(frame).unwrap();
+    assert!(doc.contains(frame) && doc.contains(other));
+    assert!(!doc.contains(inner) && !doc.contains(leaf));
+    assert!(doc.get(frame).unwrap().children.is_empty());
+}

crates/engine/src/assets/components.rs

@@ -147,6 +147,10 @@ pub fn inside_instance(doc: &Document, id: NodeId) -> bool {
 /// main layer's, for files from before `modes` was an override group. Copies follow their main
 /// layer's modes, so a layer on other modes chose them itself.
 pub fn mark_layer_modes(doc: &mut Document) {
+    // Without an instance nothing can be inside one: skip the per-layer ancestry lookups.
+    if !doc.nodes().any(|n| matches!(n.kind, NodeKind::Instance { .. })) {
+        return;
+    }
     let chose: Vec<NodeId> = doc
         .nodes()
         .filter(|n| !n.overrides.contains("modes") && n.source.and_then(|s| doc.node(s)).is_some_and(|m| m.var_modes != n.var_modes))

crates/engine/src/assets/library.rs

@@ -277,8 +277,16 @@ pub fn default_selection(doc: &Document, prev: Option<&LibraryManifest>) -> Sele
 fn alias_closure(vars: &Variables, seeds: impl IntoIterator<Item = VariableId>) -> BTreeSet<VariableId> {
     let mut out = BTreeSet::new();
     let mut stack: Vec<VariableId> = seeds.into_iter().collect();
+    if stack.is_empty() {
+        return out;
+    }
+    // Indexed once (the first of equal ids, as `get_by_id` finds it): a scan per step is quadratic on a long alias chain.
+    let mut by_id = std::collections::HashMap::new();
+    for v in &vars.variables {
+        by_id.entry(v.id.as_str()).or_insert(v);
+    }
     while let Some(cur) = stack.pop() {
-        let Some(v) = vars.get_by_id(&cur) else { continue };
+        let Some(v) = by_id.get(cur.as_str()).copied() else { continue };
         if out.len() >= MAX_ASSETS || !out.insert(v.id.clone()) {
             continue;
         }

crates/engine/src/assets/library_server.rs

@@ -79,10 +79,13 @@ pub fn usage(doc: &Document, library: &str) -> Usage {
     let records: std::collections::BTreeMap<NodeId, NodeId> =
         doc.libraries.components.iter().filter(|r| r.library == library).map(|r| (r.root, r.key)).collect();
     if !records.is_empty() {
+        // One component's asset root is looked up once, however many instances use it.
+        let mut roots = std::collections::BTreeMap::<NodeId, Option<NodeId>>::new();
         for n in doc.nodes() {
             if let NodeKind::Instance { component, .. } = &n.kind
                 && store.is_none_or(|st| doc.page_of(n.id) != Some(st))
-                && let Some(key) = crate::library::asset_root(doc, *component).and_then(|r| records.get(&r))
+                && let Some(key) =
+                    roots.entry(*component).or_insert_with(|| crate::library::asset_root(doc, *component)).and_then(|r| records.get(&r))
             {
                 let c = counts.entry(*key).or_default();
                 *c = c.saturating_add(1);

crates/engine/src/assets/style_vars.rs

@@ -33,6 +33,7 @@ pub fn field_type(kind: &StyleKind, key: &str) -> Option<VariableType> {
             (EffectKind::DropShadow(_) | EffectKind::InnerShadow(_), "color") => Some(Color),
             (EffectKind::DropShadow(_) | EffectKind::InnerShadow(_), "radius" | "spread" | "offsetX" | "offsetY") => Some(Number),
             (EffectKind::LayerBlur(_) | EffectKind::BackgroundBlur(_), "radius" | "startRadius") => Some(Number),
+            (EffectKind::Glass(_), f) if figcraft_doc::Glass::BOUND_FIELDS.contains(&f) => Some(Number),
             _ => None,
         },
         (StyleKind::Grid { grids }, Some((BoundList::Grids, i, "size" | "count" | "gutter" | "offset"))) => grids.get(i).map(|_| Number),

crates/engine/src/automation/batch.rs

@@ -156,14 +156,20 @@ impl BatchScope {
         lookup(result, path).cloned().map_err(|why| fail(format!("{who}'s result has no `{path}`{why}")))
     }
 
+    /// Most step names a missing-reference error lists.
+    const NAME_HINTS: usize = 12;
+
     fn known_names(&self) -> String {
         let mut names: Vec<_> = self.names.iter().collect();
         names.sort_by_key(|(_, i)| **i);
         if names.is_empty() {
             return "no step has an `as` name".into();
         }
-        let list: Vec<_> = names.iter().map(|(name, i)| format!("\"{name}\" is step {i}")).collect();
-        list.join(", ")
+        // A few of them: the list is built for every missing reference and, with `onError:
+        // continue`, kept for each, so a long table would cost its length per failed step.
+        let list: Vec<_> = names.iter().take(Self::NAME_HINTS).map(|(name, i)| format!("\"{name}\" is step {i}")).collect();
+        let more = names.len().saturating_sub(Self::NAME_HINTS);
+        if more > 0 { format!("{}, {more} more", list.join(", ")) } else { list.join(", ") }
     }
 }
 

crates/engine/src/binding_lists_tests.rs

@@ -98,6 +98,41 @@ fn effect_moves_and_removals_reject_junk() {
     assert_eq!(s.doc().unwrap().node(r).unwrap().effects.len(), 1);
 }
 
+fn glass(s: &Session, r: NodeId) -> figcraft_doc::Glass {
+    match s.doc().unwrap().node(r).unwrap().effects.first().map(|e| &e.kind) {
+        Some(EffectKind::Glass(g)) => g.clone(),
+        k => panic!("{k:?}"),
+    }
+}
+
+#[test]
+fn glass_fields_take_number_variables() {
+    let (mut s, r) = setup();
+    ex(&mut s, "effect.add", json!({"ids": [r], "type": "glass"}));
+    // Percent fields read the variable as the Design panel shows them; `radius` is the frost.
+    ex(&mut s, "variable.bind", json!({"ids": [r], "field": "effects/0/splay", "variable": "large"}));
+    ex(&mut s, "variable.bind", json!({"ids": [r], "field": "effects/0/radius", "variable": "small"}));
+    ex(&mut s, "variable.bind", json!({"ids": [r], "field": "effects/0/depth", "variable": "large"}));
+    let g = glass(&s, r);
+    assert_eq!((g.splay, g.frost, g.depth), (0.3, 2.0, 30.0));
+    // A new value follows, clamped to the field's range (frost stops at 100).
+    ex(&mut s, "variable.set", json!({"variable": "small", "value": 150}));
+    ex(&mut s, "variable.set", json!({"variable": "large", "value": 75}));
+    let g = glass(&s, r);
+    assert_eq!((g.splay, g.frost, g.depth), (0.75, figcraft_doc::Glass::MAX_FROST, 75.0));
+    // A colour variable doesn't fit a glass field.
+    assert!(s.execute("variable.bind", &json!({"ids": [r], "field": "effects/0/refraction", "variable": "brand"})).is_err());
+    // An effect style binds them too, and every layer using it follows.
+    let fx = ex_value(&mut s, "style.create", json!({"type": "effect", "name": "Pane", "from": r}))["id"].as_str().unwrap().to_string();
+    ex(&mut s, "style.bind", json!({"style": fx, "field": "effects/0/refraction", "variable": "large"}));
+    assert_eq!(glass(&s, r).refraction, 0.75);
+    assert!(s.execute("style.bind", &json!({"style": fx, "field": "effects/0/spread", "variable": "large"})).is_err(), "glass has no spread");
+}
+
+fn ex_value(s: &mut Session, cmd: &str, p: serde_json::Value) -> serde_json::Value {
+    s.execute(cmd, &p).unwrap_or_else(|e| panic!("{cmd}: {e}"))
+}
+
 fn fill_hex(s: &Session, r: NodeId) -> Vec<String> {
     s.doc().unwrap().node(r).unwrap().fills.iter().filter_map(|p| p.solid_color()).map(|c| c.to_hex()).collect()
 }

crates/engine/src/canvas/shapebuilder.rs

@@ -109,7 +109,9 @@ pub fn eligible(doc: &Document, ids: &[NodeId]) -> Vec<NodeId> {
             out.push(id);
         }
     }
-    let ids: Vec<NodeId> = ids.iter().copied().filter(|i| doc.contains(*i)).collect();
+    // Each id counts once: a repeated group must not be walked once per repeat.
+    let mut seen = std::collections::BTreeSet::new();
+    let ids: Vec<NodeId> = ids.iter().copied().filter(|i| doc.contains(*i) && seen.insert(*i)).collect();
     let mut out = Vec::new();
     for id in roots(doc, &ids) {
         walk(doc, id, 0, &mut out);

crates/engine/src/cmd/arrange.rs

@@ -465,7 +465,8 @@ pub fn scale_node(doc: &mut Document, id: NodeId, k: f64) -> Result<()> {
                 }
                 EffectKind::Glass(g) => {
                     g.depth *= k;
-                    g.frost *= k;
+                    // From the frost it draws with (an older file's past 100 draws at 100).
+                    g.frost = (g.sanitized().frost * k).min(figcraft_doc::Glass::MAX_FROST);
                 }
             }
         }

crates/engine/src/cmd/comment.rs

@@ -373,10 +373,11 @@ fn listed<'s>(cmd: &str, s: &'s Session, p: &Value, who: &str, people: &[&str])
 
 /// Add the names `text` @mentions to `named` as `{name, known, you}`, each once.
 fn push_mentions(named: &mut Vec<Value>, text: &str, people: &[&str], user: &str) {
+    // `known` and `you` follow from the name, so the name alone tells a repeat.
+    let mut seen: std::collections::BTreeSet<String> = named.iter().filter_map(|v| v.get("name")?.as_str().map(str::to_string)).collect();
     for (name, known) in mentioned(text, people) {
-        let v = json!({"name": name, "known": known, "you": known && name.eq_ignore_ascii_case(user)});
-        if !named.contains(&v) {
-            named.push(v);
+        if seen.insert(name.to_string()) {
+            named.push(json!({"name": name, "known": known, "you": known && name.eq_ignore_ascii_case(user)}));
         }
     }
 }

crates/engine/src/cmd/props.rs

@@ -115,6 +115,8 @@ pub(crate) fn enum_of<T: serde::de::DeserializeOwned>(v: &Value) -> Option<T> {
     let norm: String = {
         let mut out = String::new();
         let mut up = false;
+        // Once, not per character: a long value made this quadratic before it was refused.
+        let no_lowercase = s.chars().all(|c| !c.is_lowercase() || !c.is_alphabetic());
         for (i, ch) in s.trim().chars().enumerate() {
             if ch == '_' || ch == '-' || ch == ' ' {
                 up = true;
@@ -125,7 +127,7 @@ pub(crate) fn enum_of<T: serde::de::DeserializeOwned>(v: &Value) -> Option<T> {
             } else if up {
                 out.extend(ch.to_uppercase());
                 up = false;
-            } else if s.chars().all(|c| !c.is_lowercase() || !c.is_alphabetic()) {
+            } else if no_lowercase {
                 out.extend(ch.to_lowercase());
             } else {
                 out.push(ch);

crates/engine/src/cmd/styles.rs

@@ -53,7 +53,7 @@ pub fn specs() -> Vec<CommandSpec> {
         spec!(
             "style.bind",
             "Bind variable in style",
-            "{style, field, variable? (id or name; none: unbind)}  bind a variable to a field of the style's value: a paint style's `fills/<i>/color` (or `fill`: its first paint) and `fills/<i>/stops/<j>/color`, an effect style's `effects/<i>/<color|radius|spread|offsetX|offsetY|startRadius>`, a grid style's `layoutGrids/<i>/<size|count|gutter|offset>`, a text style's `fontSize|lineHeight|letterSpacing` (numbers, px) and `fontFamily|fontStyle` (strings). Every layer using the style shows the field resolved in its own modes; the style keeps it resolved in the default modes",
+            "{style, field, variable? (id or name; none: unbind)}  bind a variable to a field of the style's value: a paint style's `fills/<i>/color` (or `fill`: its first paint) and `fills/<i>/stops/<j>/color`, an effect style's `effects/<i>/<color|radius|spread|offsetX|offsetY|startRadius>` (glass: `lightAngle|lightIntensity|refraction|depth|dispersion|radius|splay`), a grid style's `layoutGrids/<i>/<size|count|gutter|offset>`, a text style's `fontSize|lineHeight|letterSpacing` (numbers, px) and `fontFamily|fontStyle` (strings). Every layer using the style shows the field resolved in its own modes; the style keeps it resolved in the default modes",
             true,
             bind_style
         ),
@@ -196,7 +196,7 @@ pub fn specs() -> Vec<CommandSpec> {
         spec!(
             "variable.bind",
             "Bind variable",
-            "{ids?, field (fill|stroke (first paint)|fills/<i>/color|strokes/<i>/color|fills/<i>/stops/<j>/color (gradient stops)|effects/<i>/<offsetX|offsetY|radius|startRadius|spread|color>|layoutGrids/<i>/<size|count|gutter|offset>|componentProperties/<name> (instances: boolean/text properties; variant properties take string variables naming a value)|width|height|opacity (percent)|cornerRadius|gap|paddingHorizontal|characters|visible|fontSize…; list indices bottom first), variable (null unbinds)}",
+            "{ids?, field (fill|stroke (first paint)|fills/<i>/color|strokes/<i>/color|fills/<i>/stops/<j>/color (gradient stops)|effects/<i>/<offsetX|offsetY|radius|startRadius|spread|color|lightAngle|lightIntensity|refraction|depth|dispersion|splay> (glass: `radius` is its frost; intensity, refraction, dispersion and splay in percent)|layoutGrids/<i>/<size|count|gutter|offset>|componentProperties/<name> (instances: boolean/text properties; variant properties take string variables naming a value)|width|height|opacity (percent)|cornerRadius|gap|paddingHorizontal|characters|visible|fontSize…; list indices bottom first), variable (null unbinds)}",
             true,
             bind
         ),
@@ -1304,6 +1304,9 @@ pub(crate) fn set_effect_field(effects: &mut [Effect], i: usize, prop: &str, val
         (EffectKind::DropShadow(s) | EffectKind::InnerShadow(s), "color", _, VariableValue::Color(c)) => s.color = *c,
         (EffectKind::LayerBlur(b) | EffectKind::BackgroundBlur(b), "radius", Some(x), _) => b.radius = x.max(0.0),
         (EffectKind::LayerBlur(b) | EffectKind::BackgroundBlur(b), "startRadius", Some(x), _) => b.start_radius = x.max(0.0),
+        (EffectKind::Glass(g), field, Some(x), _) => {
+            g.set_bound(field, x);
+        }
         _ => {}
     }
 }

crates/engine/src/content/datafill.rs

@@ -189,14 +189,21 @@ fn fill_layers(s: &mut Session, copy: NodeId, (key, value): (&str, &Value), miss
 /// Export each copy into `dir` as `<name>.<format>` at `scale`, adding `files` (and `errors`) to
 /// `out`.
 fn export_copies(s: &mut Session, ids: &[(NodeId, String)], dir: &str, (format, scale): (&str, f64), out: &mut Value) {
-    let (mut files, mut errors, mut used) = (Vec::new(), Vec::new(), Vec::<String>::new());
+    let (mut files, mut errors) = (Vec::new(), Vec::new());
+    let mut used = std::collections::BTreeSet::<String>::new();
+    // The next number to try per base, so many copies of one name don't retry from 2 each time.
+    let mut next = std::collections::BTreeMap::<String, u64>::new();
     for (copy, name) in ids {
         // One file per copy: same or same-looking names get " 2", " 3"… (case-insensitively,
         // as macOS and Windows file systems compare names).
         let base = file_name(name);
-        let stem =
-            (1..).map(|k| if k == 1 { base.clone() } else { format!("{base} {k}") }).find(|n| !used.contains(&n.to_lowercase())).unwrap_or(base);
-        used.push(stem.to_lowercase());
+        let from = next.get(&base.to_lowercase()).copied().unwrap_or(1);
+        let (k, stem) = (from..)
+            .map(|k| (k, if k == 1 { base.clone() } else { format!("{base} {k}") }))
+            .find(|(_, n)| !used.contains(&n.to_lowercase()))
+            .unwrap_or((from, base.clone()));
+        next.insert(base.to_lowercase(), k + 1);
+        used.insert(stem.to_lowercase());
         let path = std::path::Path::new(dir).join(format!("{stem}.{format}")).to_string_lossy().to_string();
         match s.execute("file.export", &json!({"ids": [copy.0], "format": format, "scale": scale, "path": path})) {
             Ok(_) => files.push(path),

crates/engine/src/dev/codegen.rs

@@ -34,7 +34,7 @@ pub use css::{CssNames, css_var_name, css_var_of};
 use css::{css, tok};
 pub(crate) use flutter::{FLUTTER_IMPORT, Place, flutter, flutter_indent};
 use html::html;
-pub(crate) use html::{Markup, class_name};
+pub(crate) use html::{Markup, Names, class_name};
 pub(crate) use swift::swift;
 
 pub fn specs() -> Vec<CommandSpec> {

crates/engine/src/dev/codegen/html.rs

@@ -30,7 +30,7 @@ fn kind_word(n: &Node) -> &str {
 /// `rogeuin-hwamyeon`, кнопка → `knopka`, über → `uber` (per-codepoint transliteration, the slug
 /// libraries' way); a name left with nothing (symbols only) takes `kind`, and one starting with a
 /// digit keeps the `layer-` prefix.
-pub(crate) fn class_name(name: &str, kind: &str, used: &mut Vec<String>) -> String {
+pub(crate) fn class_name(name: &str, kind: &str, used: &mut Names) -> String {
     let mut base = String::new();
     for c in deunicode::deunicode(name).chars().flat_map(char::to_lowercase) {
         if c.is_ascii_alphanumeric() {
@@ -57,11 +57,30 @@ pub(crate) fn class_name(name: &str, kind: &str, used: &mut Vec<String>) -> Stri
     } else {
         base.to_string()
     };
-    let name = (1..).map(|k| if k == 1 { base.clone() } else { format!("{base}-{k}") }).find(|n| !used.contains(n)).unwrap_or(base);
-    used.push(name.clone());
+    let from = used.next.get(&base).copied().unwrap_or(1);
+    let (k, name) = (from..)
+        .map(|k| (k, if k == 1 { base.clone() } else { format!("{base}-{k}") }))
+        .find(|(_, n)| !used.used.contains(n))
+        .unwrap_or((from, base.clone()));
+    used.next.insert(base, k + 1);
+    used.insert(name.clone());
     name
 }
 
+/// The names [`class_name`] has given out, and the next suffix to try per base, so many layers
+/// sharing one name don't each retry every suffix from 2 (that was cubic in their number).
+#[derive(Default)]
+pub(crate) struct Names {
+    used: std::collections::BTreeSet<String>,
+    next: std::collections::BTreeMap<String, u64>,
+}
+
+impl Names {
+    pub fn insert(&mut self, name: String) {
+        self.used.insert(name);
+    }
+}
+
 fn html_escape(s: &str) -> String {
     s.replace('&', "&amp;").replace('<', "&lt;").replace('>', "&gt;").replace('\n', "<br>")
 }
@@ -90,7 +109,10 @@ pub(super) fn html(doc: &Document, id: NodeId) -> String {
     let ctx = Ctx::new(doc, id);
     let mut out = Markup::new(&ctx, CodeLang::Html);
     out.node(id, None, 0, "");
-    format!("{}\n<style>\n{}{}</style>\n", out.markup, out.tokens.root_rule(), out.styles)
+    // Document text can reach the stylesheet through any property: `<\/` reads back as `</` inside a CSS
+    // string and can never close the element early.
+    let css = format!("{}{}", out.tokens.root_rule(), out.styles).replace("</", "<\\/");
+    format!("{}\n<style>\n{css}</style>\n", out.markup)
 }
 
 /// Markup being built for a layer tree: HTML (`class`), React JSX (`className`), Vue
@@ -101,7 +123,7 @@ pub(crate) struct Markup<'c, 'a> {
     ctx: &'c Ctx<'a>,
     /// Html, React, Vue or Leptos.
     lang: CodeLang,
-    used: Vec<String>,
+    used: Names,
     pub markup: String,
     pub styles: String,
     pub tokens: Tokens,
@@ -158,7 +180,7 @@ impl<'c, 'a> Markup<'c, 'a> {
         Markup {
             ctx,
             lang,
-            used: Vec::new(),
+            used: Names::default(),
             markup: String::new(),
             styles: String::new(),
             tokens: Tokens::default(),
@@ -273,7 +295,7 @@ impl<'c, 'a> Markup<'c, 'a> {
         let root = n.id == self.ctx.root;
         let class = match self.root_class.take().filter(|_| root) {
             Some(c) => {
-                self.used.push(c.clone());
+                self.used.insert(c.clone());
                 c
             }
             None => {
@@ -329,7 +351,7 @@ impl<'c, 'a> Markup<'c, 'a> {
                 let open = open("div");
                 let slot_ident = slot.map(|p| match self.ctx.comp {
                     Some(c) => crate::component_codegen::slot_name(c, p),
-                    None => class_name(&p.ident, "slot", &mut Vec::new()),
+                    None => class_name(&p.ident, "slot", &mut Names::default()),
                 });
                 if let Some(p) = slot.filter(|_| kids.is_empty()) {
                     let content = if leptos {

crates/engine/src/dev/component_codegen.rs

@@ -11,7 +11,9 @@ use figcraft_doc::{Document, NodeId, NodeKind, PropDef};
 use serde_json::{Value, json};
 
 use crate::cmd::CommandSpec;
-use crate::codegen::{CodeLang, Ctx, FLUTTER_IMPORT, Markup, Place, arkui, class_name, compose, flutter, flutter_indent, indent, literal, swift};
+use crate::codegen::{
+    CodeLang, Ctx, FLUTTER_IMPORT, Markup, Names, Place, arkui, class_name, compose, flutter, flutter_indent, indent, literal, swift,
+};
 use crate::components::{prop_default_value, slot_edited, slots_of, variant_options, variant_props, variant_set};
 use crate::params::{id_of, string, targets};
 use crate::{bad, spec};
@@ -616,14 +618,14 @@ pub(crate) fn value_expr(doc: &Document, c: &Component, p: &Param, value: &Value
 /// The `<slot name="…">` of a slot parameter: unique among the component's slot parameters, unlike
 /// `class_name` called with a fresh list per parameter (two idents can lowercase alike).
 pub(crate) fn slot_name(c: &Component, p: &Param) -> String {
-    let mut used = Vec::new();
+    let mut used = Names::default();
     for q in c.params.iter().filter(|q| matches!(q.kind, ParamKind::Slot)) {
         let name = class_name(&q.ident, "slot", &mut used);
         if q.ident == p.ident {
             return name;
         }
     }
-    class_name(&p.ident, "slot", &mut Vec::new())
+    class_name(&p.ident, "slot", &mut Names::default())
 }
 
 /// The values an instance sets for `c`'s parameters, in order (`None` for other layers): variant
@@ -720,7 +722,7 @@ pub(crate) fn usage_with_styles(doc: &Document, id: NodeId, lang: CodeLang, dept
                 .filter(|(name, _, _)| is_slot(name))
                 .map(|(name, expr, _)| {
                     let slot = c.params.iter().find(|q| q.ident == *name);
-                    let name = slot.map(|p| slot_name(&c, p)).unwrap_or_else(|| class_name(name, "slot", &mut Vec::new()));
+                    let name = slot.map(|p| slot_name(&c, p)).unwrap_or_else(|| class_name(name, "slot", &mut Names::default()));
                     format!("{pad}  <template #{name}>\n{expr}{pad}  </template>\n")
                 })
                 .collect();
@@ -823,7 +825,7 @@ pub fn definition(doc: &Document, c: &Component, lang: CodeLang) -> String {
 
 /// `data-*` attribute names for variant parameters, unique among them (in order).
 fn data_attrs(variants: &[&Param]) -> Vec<String> {
-    let mut used = Vec::new();
+    let mut used = Names::default();
     variants.iter().map(|p| format!("data-{}", class_name(&p.prop, "prop", &mut used))).collect()
 }
 
@@ -832,7 +834,7 @@ fn data_attrs(variants: &[&Param]) -> Vec<String> {
 fn web(doc: &Document, c: &Component, lang: CodeLang) -> (String, String, String) {
     let ctx = Ctx { doc, root: c.comp, comp: Some(c), base: 2 };
     let root_name = c.set.and_then(|s| doc.node(s)).or_else(|| doc.node(c.comp)).map(|n| n.name.clone()).unwrap_or_default();
-    let root_class = class_name(&root_name, "component", &mut Vec::new());
+    let root_class = class_name(&root_name, "component", &mut Names::default());
     let variants: Vec<&Param> = c.params.iter().filter(|p| matches!(p.kind, ParamKind::Variant(_))).collect();
     let attr_names = data_attrs(&variants);
     let pass = |root: NodeId| {

crates/engine/src/dev/devcompare.rs

@@ -288,8 +288,10 @@ pub fn layer_changes(before: &Document, now: &Document, id: NodeId) -> Vec<PropC
 fn order(before: &Document, now: &Document, id: NodeId) -> Option<(usize, usize)> {
     let parent = now.node(id)?.parent?;
     let (pb, pa) = (before.node(parent)?, now.node(parent)?);
-    let common_b: Vec<NodeId> = pb.children.iter().rev().copied().filter(|c| pa.children.contains(c)).collect();
-    let common_a: Vec<NodeId> = pa.children.iter().rev().copied().filter(|c| pb.children.contains(c)).collect();
+    let (in_b, in_a): (std::collections::BTreeSet<NodeId>, std::collections::BTreeSet<NodeId>) =
+        (pb.children.iter().copied().collect(), pa.children.iter().copied().collect());
+    let common_b: Vec<NodeId> = pb.children.iter().rev().copied().filter(|c| in_a.contains(c)).collect();
+    let common_a: Vec<NodeId> = pa.children.iter().rev().copied().filter(|c| in_b.contains(c)).collect();
     let (ib, ia) = (common_b.iter().position(|c| *c == id)?, common_a.iter().position(|c| *c == id)?);
     (ib != ia).then_some((ib + 1, ia + 1))
 }

crates/engine/src/dev/devinspect.rs

@@ -475,7 +475,7 @@ pub fn properties_with(doc: &Document, id: NodeId, fmt: ColorFormat) -> Vec<Sect
                     pct(g.refraction),
                     num(g.depth),
                     pct(g.dispersion),
-                    num(g.frost),
+                    num(g.sanitized().frost),
                     pct(g.splay)
                 ),
             ),

crates/engine/src/effects_tests.rs

@@ -95,6 +95,32 @@ fn scaling_scales_grain_and_glass() {
     assert_eq!((g.refraction, nz.density), (d.refraction, 0.5));
 }
 
+#[test]
+fn scaling_a_frost_from_an_older_file_starts_from_what_it_draws() {
+    // A frost of 150, saved before the 0–100 range, draws at 100: halved, it draws at 50.
+    let mut s = Session::new();
+    let r = rect(&mut s);
+    s.execute("effect.add", &json!({"ids": [r], "type": "glass"})).unwrap();
+    s.execute("effect.set", &json!({"ids": [r], "index": 0, "effect": {"type": "glass", "frost": 150}})).unwrap();
+    s.execute("transform.scale", &json!({"ids": [r], "factor": 0.5})).unwrap();
+    let EffectKind::Glass(g) = &s.doc().unwrap().node(r).unwrap().effects[0].kind else { panic!() };
+    assert_eq!(g.frost, 50.0);
+}
+
+#[test]
+fn inspect_shows_a_frost_from_an_older_file_as_it_draws() {
+    // A frost of 150, saved before the 0–100 range, draws at 100: Dev Mode says 100 as CSS does.
+    let mut s = Session::new();
+    let r = rect(&mut s);
+    s.execute("effect.add", &json!({"ids": [r], "type": "glass"})).unwrap();
+    s.execute("effect.set", &json!({"ids": [r], "index": 0, "effect": {"type": "glass", "frost": 150}})).unwrap();
+    let doc = s.doc().unwrap();
+    let sections = crate::devinspect::properties(doc, r);
+    let glass = &sections.iter().find(|s| s.title == "Effects").unwrap().rows[0];
+    assert!(glass.value.contains(" frost 100 "), "{}", glass.value);
+    assert!(code_for(doc, r, CodeLang::Css).contains("backdrop-filter: blur(50px);"));
+}
+
 #[test]
 fn inspect_and_css_show_the_new_effects() {
     let mut s = Session::new();

crates/engine/src/events.rs

@@ -127,12 +127,15 @@ pub fn topics(v: Option<&Value>) -> Result<Vec<String>, String> {
     for t in list {
         let Some(s) = t.as_str() else { return Err("`topics` must be an array of strings".into()) };
         match s {
+            // Each once: the list is scanned for every retained event under the log's lock, so
+            // a long list of repeats would multiply that work.
+            "comments" | "document" | "all" if out.iter().any(|t| t == s) => {}
             "comments" | "document" | "all" => out.push(s.to_string()),
             other => return Err(format!("unknown topic `{other}` (comments, document, all)")),
         }
     }
-    if out.is_empty() {
-        out.push("all".into());
+    if out.is_empty() || out.iter().any(|t| t == "all") {
+        out = vec!["all".into()];
     }
     Ok(out)
 }

crates/engine/src/events_tests.rs

@@ -193,6 +193,10 @@ fn topics_parse_and_reject_unknown_names() {
     assert_eq!(events::topics(Some(&json!([]))).unwrap(), vec!["all".to_string()]);
     assert_eq!(events::topics(Some(&json!(["comments", "document"]))).unwrap(), vec!["comments".to_string(), "document".to_string()]);
     assert!(events::topics(Some(&json!(["nope"]))).is_err());
+    // Repeats collapse (the list is scanned per event under the log's lock), and `all` is all.
+    let many: Vec<&str> = std::iter::repeat_n("comments", 10_000).chain(["document"]).collect();
+    assert_eq!(events::topics(Some(&json!(many))).unwrap(), vec!["comments".to_string(), "document".to_string()]);
+    assert_eq!(events::topics(Some(&json!(["comments", "all", "document"]))).unwrap(), vec!["all".to_string()]);
     assert!(events::topics(Some(&json!("comments"))).is_err());
 }
 

crates/engine/src/extensions/plugins.rs

@@ -149,6 +149,16 @@ fn refusal(m: &Manifest, command: &str, params: &Value) -> Option<String> {
     if DENIED.iter().any(|p| command.starts_with(p)) && !ALLOWED.contains(&command) {
         return Some(format!("`{command}` isn't available to plugins"));
     }
+    // A preview runs its inner command, which the plugin's permissions and the denied list must cover too.
+    // An inner command that can't be previewed (a nested preview) is refused by the preview itself,
+    // before it runs: descending into its parameters first would only rescan them.
+    if command == "text.preview"
+        && let Some(inner) = get(params, "command").and_then(Value::as_str)
+        && crate::textpreview::PREVIEWABLE.contains(&inner)
+        && let Some(why) = refusal(m, inner, get(params, "params").unwrap_or(&Value::Null))
+    {
+        return Some(why);
+    }
     // A widget's own data is FigCraft's to write, so no plugin can forge or retarget a widget.
     if writes_widget_data(params, 0) {
         return Some(format!("plugins can't write `{}…` layer data", crate::widgets::DATA_PREFIX));

crates/engine/src/extensions/widgets.rs

@@ -157,8 +157,9 @@ fn state_of(doc: &Document, w: NodeId) -> Map<String, Value> {
 /// fields), each once, in layer order.
 fn names(doc: &Document, w: NodeId, key: &str) -> Vec<String> {
     let mut out: Vec<String> = Vec::new();
+    let mut seen = std::collections::BTreeSet::new();
     for t in doc.subtree(w).into_iter().filter_map(|i| doc.node(i)?.plugin_data.get(key).cloned()) {
-        if !out.contains(&t) {
+        if seen.insert(t.clone()) {
             out.push(t);
         }
     }
@@ -243,9 +244,7 @@ fn build(s: &mut Session, plugin: &str, w: NodeId, r: &WidgetRender) -> Result<(
     if !is_widget(n) || n.plugin_data.get(PLUGIN).map(String::as_str) != Some(plugin) {
         return Err(bad(cmd, "the layer is no longer this plugin's widget"));
     }
-    for c in n.children.clone() {
-        doc.remove(c)?;
-    }
+    doc.remove_children(w)?;
     crate::cmd::props::apply(cmd, doc, w, &props(&r.root, true))?;
     let n = doc.get_mut(w)?;
     n.locked = false;

crates/engine/src/html_codegen_tests.rs

@@ -73,6 +73,20 @@ fn non_ascii_layer_names_transliterate_into_readable_classes() {
     assert!(code.contains("<p class=\"rogeuin\">") && code.contains("<p class=\"rogeuin-2\">"), "{code}");
 }
 
+#[test]
+fn many_layers_with_one_name_get_numbered_in_linear_time() {
+    // Each name used to retry every suffix from 2 against a list: cubic in their number.
+    let mut used = crate::codegen::Names::default();
+    let start = std::time::Instant::now();
+    let names: Vec<String> = (0..20_000).map(|_| crate::codegen::class_name("Card / Title", "frame", &mut used)).collect();
+    assert!(start.elapsed() < std::time::Duration::from_secs(5), "{:?}", start.elapsed());
+    assert_eq!(names[0], "card-title");
+    assert_eq!(names[1], "card-title-2");
+    assert_eq!(names[19_999], "card-title-20000");
+    let distinct: std::collections::BTreeSet<&String> = names.iter().collect();
+    assert_eq!(distinct.len(), names.len());
+}
+
 #[test]
 fn other_scripts_and_symbol_names_transliterate_or_fall_back_to_the_kind() {
     let mut s = Session::new();
@@ -163,3 +177,16 @@ fn rem_preserves_text_property_default() {
         }
     }
 }
+
+#[test]
+fn the_stylesheet_never_contains_a_closing_style_tag_from_document_text() {
+    let mut s = Session::new();
+    let f = id(s.execute("frame.create", &json!({"x": 0, "y": 0, "width": 100, "height": 100})).unwrap());
+    let t = id(s.execute("text.create", &json!({"text": "x", "x": 0, "y": 0})).unwrap());
+    s.execute("node.set", &json!({"id": t, "props": {"fontFamily": "a</style><script>alert(1)</script>"}})).unwrap();
+    s.execute("node.reparent", &json!({"ids": [t], "parent": f})).unwrap();
+    let code = code_for(s.doc().unwrap(), f, CodeLang::Html);
+    let (_, css) = code.split_once("<style>").unwrap();
+    assert_eq!(css.matches("</style>").count(), 1, "{code}");
+    assert!(!code.contains("<script>"), "{code}");
+}

crates/engine/src/panels_behaviour_tests.rs

@@ -277,6 +277,11 @@ fn renaming_several_layers_by_the_documented_codes() {
     assert_eq!(r(None, "$n", Some(1e30), "a"), "1000000000000");
     assert_eq!(r(None, "$n", Some(f64::NAN), "a"), "1");
     assert_eq!(r(Some("é"), "e", None, "café é"), "cafe e");
+    // A template is expanded once per match, so its length is capped (1,000 characters).
+    let long = "$nn".repeat(400);
+    assert!(crate::rename::BatchRename::new(Some("a"), false, &long, None, None).is_err());
+    assert!(crate::rename::BatchRename::new(None, false, "x", Some(&long), None).is_err_and(|e| e.contains("pattern")));
+    assert!(crate::rename::BatchRename::new(Some("a"), false, &"$nn".repeat(300), None, None).is_ok());
 }
 
 #[test]

crates/engine/src/plugins_tests.rs

@@ -153,6 +153,30 @@ fn read_only_plugins_and_allowlists_are_enforced() {
     assert_eq!(node(&s, a).name, "Rectangle");
 }
 
+#[test]
+fn a_preview_is_held_to_the_permissions_of_the_command_it_shows() {
+    let mut s = Session::new();
+    let a = rect(&mut s, 0.0);
+    // Only text.preview is allowed: the node.set it would run is not.
+    install(
+        &mut s,
+        manifest("org.test.previewer", "write", &["text.preview"]),
+        &script(&[("text.preview", json!({"command": "node.set", "params": {"id": a, "props": {"name": "x"}}}))], OnRefusal::Fail, ""),
+    );
+    let e = run_err(&mut s, "org.test.previewer");
+    assert!(e.contains("`node.set` isn't in the commands"), "{e}");
+    assert_eq!(node(&s, a).name, "Rectangle");
+}
+
+#[test]
+fn a_nested_preview_is_refused_by_the_preview_itself() {
+    let mut s = Session::new();
+    let nested = json!({"command": "text.preview", "params": {"command": "node.set", "params": {"props": {"name": "x"}}}});
+    install(&mut s, manifest("org.test.nested", "write", &["text.preview"]), &script(&[("text.preview", nested)], OnRefusal::Fail, ""));
+    let e = run_err(&mut s, "org.test.nested");
+    assert!(e.contains("can't be previewed"), "{e}");
+}
+
 #[test]
 fn files_dialogs_history_and_plugins_are_off_limits() {
     let mut s = Session::new();

crates/engine/src/selection/rename.rs

@@ -9,6 +9,9 @@ use figcraft_doc::{Document, NodeId};
 
 /// Longest match pattern accepted (characters).
 const MAX_FIND: usize = 1_000;
+/// Longest replacement or pattern template accepted (characters): each is expanded again for
+/// every match, so its length multiplies the work of a rename.
+const MAX_TEMPLATE: usize = 1_000;
 /// Longest name a rename produces (characters).
 const MAX_NAME: usize = 10_000;
 /// Widest zero padding of a number code.
@@ -50,6 +53,12 @@ impl BatchRename {
             }
             Some(f) => Some(Find::Text(f.to_string())),
         };
+        if replace.chars().count() > MAX_TEMPLATE {
+            return Err(format!("the replacement is longer than {MAX_TEMPLATE} characters"));
+        }
+        if pattern.is_some_and(|p| p.chars().count() > MAX_TEMPLATE) {
+            return Err(format!("the pattern is longer than {MAX_TEMPLATE} characters"));
+        }
         let start = start.filter(|s| s.is_finite()).map_or(1, |s| s.clamp(0.0, 1e12).round() as u64);
         Ok(Self { find, replace: replace.to_string(), pattern: pattern.map(str::to_string), start })
     }

crates/engine/src/shapebuilder_tests.rs

@@ -217,6 +217,15 @@ fn remove_mode_and_escape() {
     assert!(s.execute("shapeBuilder.mode", &json!({"mode": "sideways"})).is_err());
 }
 
+#[test]
+fn a_group_named_many_times_is_walked_once() {
+    let mut s = Session::new();
+    let (a, b) = squares(&mut s);
+    let g = id(&ex(&mut s, "object.group", json!({"ids": [a, b]})));
+    let r = ex(&mut s, "shapeBuilder.regions", json!({"ids": vec![g; 500]}));
+    assert_eq!(r["sources"], json!([a, b]));
+}
+
 #[test]
 fn groups_rotated_and_ineligible_layers() {
     let mut s = Session::new();

crates/format/src/fig.rs

@@ -72,6 +72,9 @@ use kiwi::{Kv, Schema};
 /// Largest `canvas.fig` member read, and largest decompressed chunk.
 const MAX_CANVAS: u64 = 256 * 1024 * 1024;
 const MAX_CHUNK: u64 = 512 * 1024 * 1024;
+/// Largest decompressed schema chunk: Figma's schema unpacks to well under 1 MB, so a schema that
+/// inflates past this is refused before its definitions are decoded.
+const MAX_SCHEMA: u64 = 16 * 1024 * 1024;
 /// Largest image member read.
 const MAX_IMAGE: u64 = figcraft_doc::ImageData::MAX_BYTES;
 /// Total decompressed ZIP image bytes read per import: the native image budget (`IMAGE_BUDGET`) on
@@ -324,7 +327,7 @@ fn decode_canvas(canvas: &[u8]) -> Result<(Schema, Vec<u8>), FormatError> {
     let (Some(schema), Some(message)) = (it.next(), it.next()) else {
         return Err(corrupt("canvas.fig needs a schema and a message chunk"));
     };
-    let schema = Schema::decode(&inflate(schema)?).map_err(|e| corrupt(e.to_string()))?;
+    let schema = Schema::decode(&inflate_within(schema, MAX_SCHEMA)?).map_err(|e| corrupt(e.to_string()))?;
     Ok((schema, inflate(message)?))
 }
 
@@ -347,18 +350,23 @@ fn chunks(canvas: &[u8]) -> Result<Vec<&[u8]>, FormatError> {
 
 /// Decompress a chunk: zstd (by its magic number), else raw deflate, else zlib.
 fn inflate(data: &[u8]) -> Result<Vec<u8>, FormatError> {
-    fn capped(r: impl Read) -> Option<Vec<u8>> {
+    inflate_within(data, MAX_CHUNK)
+}
+
+/// [`inflate`] refusing a chunk that unpacks to more than `max` bytes.
+fn inflate_within(data: &[u8], max: u64) -> Result<Vec<u8>, FormatError> {
+    let capped = |r: &mut dyn Read| -> Option<Vec<u8>> {
         let mut out = Vec::new();
-        r.take(MAX_CHUNK + 1).read_to_end(&mut out).ok()?;
-        (out.len() as u64 <= MAX_CHUNK).then_some(out)
-    }
+        r.take(max.saturating_add(1)).read_to_end(&mut out).ok()?;
+        (out.len() as u64 <= max).then_some(out)
+    };
     if data.starts_with(&[0x28, 0xB5, 0x2F, 0xFD]) {
         let mut src = data;
-        let dec = ruzstd::decoding::StreamingDecoder::new(&mut src).map_err(|e| corrupt(format!("zstd: {e}")))?;
-        return capped(dec).ok_or_else(|| corrupt("damaged or oversized zstd chunk"));
+        let mut dec = ruzstd::decoding::StreamingDecoder::new(&mut src).map_err(|e| corrupt(format!("zstd: {e}")))?;
+        return capped(&mut dec).ok_or_else(|| corrupt("damaged or oversized zstd chunk"));
     }
-    capped(flate2::read::DeflateDecoder::new(data))
-        .or_else(|| capped(flate2::read::ZlibDecoder::new(data)))
+    capped(&mut flate2::read::DeflateDecoder::new(data))
+        .or_else(|| capped(&mut flate2::read::ZlibDecoder::new(data)))
         .ok_or_else(|| corrupt("damaged or oversized deflate chunk"))
 }
 

crates/format/src/fig/export/paint.rs

@@ -234,7 +234,7 @@ impl<'d> Exporter<'d> {
             }
             EffectKind::Glass(g) => {
                 self.warn("glass effects keep only their frost");
-                f.extend([("type", e("GLASS")), ("radius", fl(g.frost))]);
+                f.extend([("type", e("GLASS")), ("radius", fl(g.sanitized().frost))]);
             }
         }
         o(f)

crates/format/src/fig/export_tests.rs

@@ -1243,6 +1243,25 @@ fn local_samples_round_trip() {
     }
 }
 
+#[test]
+fn a_glass_frost_is_written_as_it_draws() {
+    // A frost saved before the 0–100 range (or not a number) is written at what it draws: 100, or
+    // the default.
+    for (frost, written) in [(12.0, 12.0), (500.0, Glass::MAX_FROST), (f64::NAN, Glass::default().frost)] {
+        let mut doc = Document::new("glass");
+        let page = doc.first_page().unwrap();
+        let r = doc.create(page, NodeKind::Rectangle, "Pane", 0.0, 0.0, 24.0, 24.0).unwrap();
+        doc.get_mut(r).unwrap().effects = vec![Effect { kind: EffectKind::Glass(Glass { frost, ..Glass::default() }), visible: true }];
+        let (bytes, _) = export(&doc, None).unwrap();
+        let archive = Archive::open(&bytes).unwrap();
+        let (schema, message) = decode_canvas(&archive.canvas).unwrap();
+        let msg = schema.decode_message(schema.find("Message").unwrap(), &message).unwrap();
+        let pane = msg.get("nodeChanges").unwrap().list().iter().find(|nc| nc.get("name").and_then(Kv::str) == Some("Pane")).unwrap();
+        let radius = pane.get("effects").unwrap().list()[0].get("radius").and_then(Kv::f64).unwrap();
+        assert_eq!(radius, written, "frost {frost}");
+    }
+}
+
 #[test]
 fn a_vector_drawable_export_setting_is_written_as_svg_with_a_warning() {
     let mut doc = Document::new("vd");

crates/format/src/fig/kiwi.rs

@@ -6,6 +6,7 @@
 //! Everything here reads untrusted bytes: reads are bounds-checked, nesting is capped, array
 //! counts can't exceed the bytes left, and the total number of decoded values is capped.
 
+use std::collections::HashMap;
 use std::fmt;
 
 /// Deepest struct/message nesting decoded.
@@ -32,6 +33,9 @@ const MAX_VALUES: usize = 32 << 20;
 /// Most definitions in a schema, and fields in one definition.
 const MAX_DEFS: usize = 10_000;
 const MAX_FIELDS: usize = 10_000;
+/// Most fields in a schema, every definition together: Figma's own schema has a few thousand, and
+/// without a total a schema of [`MAX_DEFS`] wide definitions could hold 100 million field records.
+const MAX_SCHEMA_FIELDS: usize = 200_000;
 
 #[derive(Debug, PartialEq, Eq)]
 pub struct KiwiError(pub String);
@@ -252,6 +256,7 @@ impl Schema {
         }
         let mut defs = Vec::with_capacity(count);
         let mut raw_types = Vec::new();
+        let mut total_fields = 0usize;
         for _ in 0..count {
             let name = r.string()?;
             let kind = match r.byte()? {
@@ -261,7 +266,8 @@ impl Schema {
                 k => return err(format!("schema: unknown definition kind {k}")),
             };
             let n = r.var_uint()? as usize;
-            if n > MAX_FIELDS || n > r.left() {
+            total_fields = total_fields.saturating_add(n);
+            if n > MAX_FIELDS || n > r.left() || total_fields > MAX_SCHEMA_FIELDS {
                 return err("schema: too many fields");
             }
             let mut fields = Vec::with_capacity(n);
@@ -308,7 +314,7 @@ impl Schema {
 
     /// [`Self::decode_message`] within `budget` values (see [`value_budget`]).
     pub fn decode_message_within<'s>(&'s self, root: usize, data: &[u8], budget: usize) -> Result<Kv<'s>, KiwiError> {
-        let mut d = Decoder { schema: self, r: Reader { data, pos: 0 }, budget };
+        let mut d = Decoder { schema: self, r: Reader { data, pos: 0 }, budget, ids: vec![None; self.defs.len()] };
         d.def(root, 0)
     }
 }
@@ -322,6 +328,10 @@ struct Decoder<'s, 'b> {
     schema: &'s Schema,
     r: Reader<'b>,
     budget: usize,
+    /// Per definition, the index of the first field with each id (message field ids, enum
+    /// values), built the first time the definition is decoded: a message can carry many tags
+    /// against a wide definition, and a scan per tag would multiply the two.
+    ids: Vec<Option<HashMap<u32, usize>>>,
 }
 
 impl<'s> Decoder<'s, '_> {
@@ -330,6 +340,19 @@ impl<'s> Decoder<'s, '_> {
         Ok(())
     }
 
+    /// The first field of definition `i` with id (or enum value) `id`.
+    fn field_by_id(&mut self, i: usize, id: u32) -> Option<&'s Field> {
+        let fields = &self.schema.defs.get(i)?.fields;
+        let ids = self.ids.get_mut(i)?.get_or_insert_with(|| {
+            let mut m = HashMap::with_capacity(fields.len());
+            for (j, f) in fields.iter().enumerate() {
+                m.entry(f.value).or_insert(j);
+            }
+            m
+        });
+        fields.get(*ids.get(&id)?)
+    }
+
     fn def(&mut self, i: usize, depth: usize) -> Result<Kv<'s>, KiwiError> {
         if depth > MAX_DEPTH {
             return err("message: nested too deeply");
@@ -340,7 +363,7 @@ impl<'s> Decoder<'s, '_> {
         match d.kind {
             Kind::Enum => {
                 let v = self.r.var_uint()?;
-                Ok(d.fields.iter().find(|f| f.value == v).map_or(Kv::Uint(u64::from(v)), |f| Kv::Enum(f.name.as_str())))
+                Ok(self.field_by_id(i, v).map_or(Kv::Uint(u64::from(v)), |f| Kv::Enum(f.name.as_str())))
             }
             Kind::Struct => {
                 let mut out = Vec::with_capacity(d.fields.len());
@@ -358,7 +381,7 @@ impl<'s> Decoder<'s, '_> {
                         out.shrink_to_fit();
                         return Ok(Kv::Object(out));
                     }
-                    let f = d.fields.iter().find(|f| f.value == id).ok_or_else(|| KiwiError(format!("message: {} has no field {id}", d.name)))?;
+                    let f = self.field_by_id(i, id).ok_or_else(|| KiwiError(format!("message: {} has no field {id}", d.name)))?;
                     out.push((f.name.as_str(), self.field(f, depth)?));
                 }
             }
@@ -379,8 +402,9 @@ impl<'s> Decoder<'s, '_> {
         if n > self.r.left() {
             return err("message: array longer than the data");
         }
+        // The field itself counts, so empty arrays can't pile up for free.
+        self.spend(1)?;
         if ty == Type::Byte {
-            self.spend(1)?;
             return Ok(Kv::Bytes(self.r.take(n)?.to_vec()));
         }
         self.spend(n)?;

crates/format/src/fig/tests.rs

@@ -1179,6 +1179,60 @@ fn scalar_fields_count_against_the_value_budget() {
     assert!(sc.decode_message_within(0, &data, 1001).is_ok());
 }
 
+#[test]
+fn empty_arrays_count_against_the_value_budget() {
+    // 1000 empty `uint[]` fields: each field is a value even with no elements, so a small budget
+    // can't be outgrown by piling up empty containers.
+    let fields = vec![Field { name: "a".into(), ty: Some(Type::Uint), array: true, value: 1 }];
+    let sc = Schema { defs: vec![Def { name: "Message".into(), kind: Kind::Message, fields }] };
+    let mut data = [1u8, 0].repeat(1000);
+    data.push(0);
+    let e = sc.decode_message_within(0, &data, 10).unwrap_err();
+    assert_eq!(e.0, "message: too many values");
+    assert!(sc.decode_message_within(0, &data, 1001).is_ok());
+}
+
+#[test]
+fn message_tags_find_their_field_by_id_in_a_wide_definition() {
+    // A wide definition: every tag is looked up by id, and the first field with an id wins, as
+    // before the lookup was indexed.
+    let mut fields: Vec<Field> = (1..=5000).map(|i| Field { name: format!("f{i}"), ty: Some(Type::Bool), array: false, value: i }).collect();
+    fields.push(Field { name: "shadow".into(), ty: Some(Type::Bool), array: false, value: 7 });
+    let sc = Schema { defs: vec![Def { name: "Message".into(), kind: Kind::Message, fields }] };
+    let mut w = encode::Writer::default();
+    for _ in 0..20_000 {
+        w.var_uint(5000);
+        w.byte(1);
+    }
+    w.var_uint(7);
+    w.byte(0);
+    w.var_uint(0);
+    let Kv::Object(out) = sc.decode_message(0, &w.0).unwrap() else { panic!() };
+    assert_eq!(out.len(), 20_001);
+    assert!(out.iter().take(20_000).all(|(n, v)| *n == "f5000" && *v == Kv::Bool(true)));
+    assert_eq!(out.last().map(|(n, _)| *n), Some("f7"));
+}
+
+#[test]
+fn a_schema_is_refused_past_its_total_field_count() {
+    // 25 definitions of 10 000 fields each: every one is within the per-definition cap, but
+    // together they pass the schema's total.
+    let mut w = encode::Writer::default();
+    w.var_uint(25);
+    for d in 0..25 {
+        w.string(&format!("D{d}"));
+        w.byte(0);
+        w.var_uint(10_000);
+        for i in 0..10_000u32 {
+            w.string("");
+            w.var_int(0);
+            w.byte(0);
+            w.var_uint(i);
+        }
+    }
+    assert_eq!(Schema::decode(&w.0).unwrap_err().0, "schema: too many fields");
+}
+
 #[test]
 fn hostile_input_is_refused() {
     // A message that contains itself, nested past the depth cap.

crates/format/src/lib.rs

@@ -1028,6 +1028,11 @@ pub fn write_file_atomic(path: &std::path::Path, bytes: &[u8]) -> std::io::Resul
         let tmp = std::path::PathBuf::from(name);
         match std::fs::OpenOptions::new().write(true).create_new(true).open(&tmp) {
             Ok(mut file) => {
+                // The replacement keeps the destination's permissions from the start, so a private
+                // file's content is never readable under default ones (the open handle still writes).
+                if let Ok(old) = std::fs::metadata(path) {
+                    let _ = file.set_permissions(old.permissions());
+                }
                 if let Err(e) = file.write_all(bytes) {
                     let _ = std::fs::remove_file(&tmp);
                     return Err(e);

crates/format/src/sketch.rs

@@ -226,11 +226,16 @@ impl<'b> Archive<'b> {
         };
         let refs = document.get("pages").and_then(Value::as_array).map(Vec::as_slice).unwrap_or_default();
         let mut pages = Vec::new();
+        let mut seen = std::collections::HashSet::new();
         for r in refs.iter().take(MAX_PAGES) {
             let Some(id) = r.get("_ref").and_then(Value::as_str).and_then(|s| s.strip_prefix("pages/")).filter(|id| valid_id(id)) else {
                 warnings.push("pages the document lists without a valid reference were skipped".into());
                 continue;
             };
+            // A page listed twice is read once: a repeated reference must not repeat the unpacking.
+            if !seen.insert(id) {
+                continue;
+            }
             match json_member(&mut z, &format!("pages/{id}.json"), max_member, &mut total) {
                 Ok(page) if page.is_object() => pages.push((id.to_string(), page)),
                 Ok(_) => warnings.push("pages that aren't JSON objects were skipped".into()),

crates/format/src/sketch/tests.rs

@@ -35,6 +35,13 @@ fn pages_become_pages_in_document_order() {
     assert_eq!(page_names(&doc), ["Beta", "Alpha"]);
 }
 
+#[test]
+fn a_page_listed_twice_is_imported_once() {
+    let z = sketch_zip("50.2", 103, document(&["A", "A", "A"]), &[page("A", "Alpha", vec![])], &[]);
+    let (doc, _) = import(&z, "f").unwrap();
+    assert_eq!(page_names(&doc), ["Alpha"]);
+}
+
 #[test]
 fn older_than_48_is_refused() {
     let z = sketch_zip("47.1", 95, document(&["P"]), &[page("P", "P", vec![])], &[]);

crates/format/src/staging_tests.rs

@@ -123,3 +123,17 @@ fn a_failed_write_leaves_the_destination_alone_and_cleans_up() {
     }
     let _ = std::fs::remove_dir_all(&d);
 }
+
+#[cfg(unix)]
+#[test]
+fn a_replaced_file_keeps_its_permissions() {
+    use std::os::unix::fs::PermissionsExt;
+    let d = dir("mode");
+    let path = d.join("a.figcraft");
+    std::fs::write(&path, b"old").unwrap();
+    std::fs::set_permissions(&path, std::fs::Permissions::from_mode(0o600)).unwrap();
+    write_file_atomic(&path, b"new").unwrap();
+    assert_eq!(std::fs::read(&path).unwrap(), b"new");
+    assert_eq!(std::fs::metadata(&path).unwrap().permissions().mode() & 0o777, 0o600);
+    let _ = std::fs::remove_dir_all(&d);
+}

crates/layout/src/lib.rs

@@ -629,14 +629,26 @@ fn distribute(items: &mut [Item], mut open: Vec<usize>, free: f64) {
             .collect();
         let violation: f64 = sized.iter().map(|(_, want, v)| v - want).sum();
         let frozen = |want: f64, v: f64| violation.abs() < 1e-9 || (violation > 0.0 && v > want + 1e-9) || (violation < 0.0 && v < want - 1e-9);
+        let mut progressed = false;
         for (i, want, v) in &sized {
             if frozen(*want, *v)
                 && let Some(it) = items.get_mut(*i)
             {
                 it.main = *v;
                 free -= *v;
+                progressed = true;
             }
         }
+        if !progressed {
+            // Several clampings each under the tolerance added up past it, so none froze: settle
+            // them all as clamped rather than go round again with nothing changed.
+            for (i, _, v) in &sized {
+                if let Some(it) = items.get_mut(*i) {
+                    it.main = *v;
+                }
+            }
+            break;
+        }
         free = free.max(0.0);
         open = sized.into_iter().filter(|(_, want, v)| !frozen(*want, *v)).map(|(i, _, _)| i).collect();
     }

crates/layout/src/tests.rs

@@ -447,3 +447,24 @@ fn grid_hostile_values() {
         assert!(x.is_finite() && y.is_finite() && w.is_finite() && h.is_finite());
     }
 }
+
+#[test]
+fn fill_children_whose_tiny_clampings_add_up_past_the_tolerance_still_settle() {
+    // Three fill children sharing 300 px, each with a minimum 5e-10 over its 100 px share: no
+    // single clamping passes the 1e-9 tolerance, but together they do, so no child froze and the
+    // distribution loop went round forever without changing anything.
+    let mut d = Document::new("t");
+    let p = d.first_page().unwrap();
+    let f = d.create(p, NodeKind::Frame, "F", 0.0, 0.0, 300.0, 100.0).unwrap();
+    d.get_mut(f).unwrap().layout = Some(AutoLayout { mode: LayoutMode::Horizontal, gap: 0.0, padding: [0.0; 4], ..Default::default() });
+    let kids: Vec<NodeId> = (0..3).map(|i| d.create(f, NodeKind::Rectangle, "K", 0.0, 0.0, 10.0, 20.0 + i as f64).unwrap()).collect();
+    for k in &kids {
+        let n = d.get_mut(*k).unwrap();
+        n.child_layout.sizing_h = Sizing::Fill;
+        n.child_layout.min_w = Some(100.0 + 5e-10);
+    }
+    layout_frame(&mut d, f, &NoMeasure);
+    for k in &kids {
+        assert!((pos(&d, *k).2 - 100.0).abs() < 1e-6, "{:?}", pos(&d, *k));
+    }
+}

crates/mcp/src/prompts.rs

@@ -128,7 +128,7 @@ pub fn get(name: &str, args: &Value) -> Result<Value, String> {
     if !(args.is_object() || args.is_null()) {
         return Err("`arguments` must be an object of strings".into());
     }
-    let mut text = p.template.replace("{verify}", VERIFY);
+    let mut values: Vec<(&str, String)> = vec![("verify", VERIFY.to_string())];
     for a in p.args {
         let v = match args.get(a.name) {
             Some(Value::String(s)) if !s.trim().is_empty() => s.clone(),
@@ -142,7 +142,49 @@ pub fn get(name: &str, args: &Value) -> Result<Value, String> {
             Some(Value::String(_)) => p.defaults.iter().find(|(k, _)| *k == a.name).map(|(_, d)| (*d).to_string()).unwrap_or_default(),
             Some(_) => return Err(format!("argument `{}` must be a string", a.name)),
         };
-        text = text.replace(&format!("{{{}}}", a.name), &v);
+        values.push((a.name, v));
     }
+    // One pass over the template, so an argument's text is never read as `{…}` syntax itself (a
+    // value holding placeholders used to be expanded again by every later replacement).
+    let mut text = String::with_capacity(p.template.len());
+    let mut rest = p.template;
+    while let Some(open) = rest.find('{') {
+        text.push_str(rest.get(..open).unwrap_or_default());
+        let after = rest.get(open..).unwrap_or_default();
+        let found = after.find('}').and_then(|close| {
+            let key = after.get(1..close)?;
+            values.iter().find(|(k, _)| *k == key).map(|(_, v)| (close, v.as_str()))
+        });
+        match found {
+            Some((close, v)) => {
+                text.push_str(v);
+                rest = after.get(close + 1..).unwrap_or_default();
+            }
+            None => {
+                text.push('{');
+                rest = after.get(1..).unwrap_or_default();
+            }
+        }
+    }
+    text.push_str(rest);
     Ok(json!({"description": p.description, "messages": [{"role": "user", "content": {"type": "text", "text": text}}]}))
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn arguments_are_text_not_template_syntax() {
+        let text = |args: Value| get("mobile_screen", &args).unwrap()["messages"][0]["content"]["text"].as_str().unwrap().to_string();
+        let plain = text(json!({"screen": "login"}));
+        assert!(plain.contains("Design a login screen") && plain.contains("iPhone 16") && plain.ends_with(VERIFY), "{plain}");
+        assert!(!plain.contains("{screen}") && !plain.contains("{verify}"), "{plain}");
+        // A value made of placeholders stays as typed, however many there are: it is never
+        // expanded again by the replacements after it (that multiplied the output without bound).
+        let bomb = "{device}{brand_color}{verify}".repeat(1000);
+        let out = text(json!({"screen": bomb.clone()}));
+        assert!(out.contains(&bomb));
+        assert!(out.len() < 3 * bomb.len(), "{}", out.len());
+    }
+}

crates/pathops/src/brush.rs

@@ -131,7 +131,9 @@ pub fn outline(path: &BezPath, width: f64, props: &StrokeProps, brush: &Brush) -
     let p = preset(&brush.preset)?;
     let unit = shape(p.id)?;
     let lines = polylines(path)?;
-    let scale = |t: f64| width * props.profile().map_or(1.0, |pr| pr.scale_at(t));
+    // Sanitized once: at most 64 points, so each sample's symmetry scan stays cheap.
+    let profile = props.profile().map(|pr| pr.sanitized());
+    let scale = |t: f64| width * profile.as_ref().map_or(1.0, |pr| pr.scale_at(t));
     let mut out = BezPath::new();
     match p.kind {
         BrushKind::Stretch => {

crates/pathops/src/brush_tests.rs

@@ -72,3 +72,14 @@ fn a_width_profile_scales_the_brush() {
     let (first, last) = (parts.first().unwrap().bounding_box(), parts.last().unwrap().bounding_box());
     assert!(last.width() > first.width() * 3.0, "{first:?} {last:?}");
 }
+
+#[test]
+fn an_unsanitized_profile_is_bounded_before_sampling() {
+    // 100k points, all past the 64-point cap and out of range: the brush reads the clamped profile.
+    let raw = WidthProfile { points: (0..100_000).map(|i| figcraft_doc::WidthPoint::new(f64::from(i), 1e300)).collect() };
+    let b = brush("taper");
+    let mut p = props(1.0, &b);
+    p.width_profile = Some(raw);
+    let out = outline(&line(50.0), 1.0, &p, &b).unwrap();
+    assert!(out.bounding_box().height() <= 2.0 * WidthProfile::MAX_SCALE);
+}

crates/pdf/src/text.rs

@@ -1,7 +1,7 @@
 //! Text: real, selectable text in embedded (subset) fonts, positioned glyph by glyph from the
 //! `figcraft_text` layout the renderer uses, with outline fallbacks.
 
-use std::collections::BTreeSet;
+use std::collections::{BTreeMap, BTreeSet};
 use std::ops::Range;
 use std::sync::Arc;
 
@@ -56,14 +56,24 @@ pub(crate) fn draw_text(ex: &mut Exporter, s: &mut Surface, n: &Node, xf: Affine
     let styles: BTreeSet<usize> = layout.glyphs.iter().map(|g| g.style).chain(layout.decorations.iter().map(|d| d.style)).collect();
     // Every run's fills, then the inner shadows over them, then the strokes on top.
     let mut stroked = Vec::new();
+    // Glyphs and decorations are grouped by style in one pass; each style's paths are built (and
+    // dropped) inside its own iteration, so only one style's paths are held at a time.
+    let mut decoration_of: BTreeMap<usize, Vec<usize>> = BTreeMap::new();
+    for (i, d) in layout.decorations.iter().enumerate() {
+        decoration_of.entry(d.style).or_default().push(i);
+    }
+    let mut glyph_of: BTreeMap<usize, Vec<usize>> = BTreeMap::new();
+    for (i, g) in layout.glyphs.iter().enumerate() {
+        glyph_of.entry(g.style).or_default().push(i);
+    }
     for k in styles {
         let fills = layout.styles.get(k).and_then(|st| st.fills.as_ref()).unwrap_or(&n.fills);
         let mut decorations = BezPath::new();
-        for d in layout.decorations.iter().filter(|d| d.style == k) {
+        for d in decoration_of.remove(&k).unwrap_or_default().into_iter().filter_map(|i| layout.decorations.get(i)) {
             decorations.extend(d.path());
         }
         let mut outlines = BezPath::new();
-        for g in layout.glyphs.iter().filter(|g| g.style == k) {
+        for g in glyph_of.remove(&k).unwrap_or_default().into_iter().filter_map(|i| layout.glyphs.get(i)) {
             outlines.extend(g.path());
         }
         outlines.extend(decorations.iter());

crates/render/src/draw.rs

@@ -1031,6 +1031,11 @@ fn masked_area(ctx: &Ctx, pix: &Pixmap, mask_id: NodeId, content: &[NodeId], xf:
 /// Mask `m` drawn as if it weren't a mask into a `w` × `h` pixmap at `xf` (a vector mask: its
 /// outline, fully opaque).
 fn mask_pixels(ctx: &Ctx, m: &Node, (w, h): (u32, u32), xf: Affine, depth: usize) -> Option<Pixmap> {
+    // A mask's content is drawn here, not through `draw_layer`, so a chain of masks inside
+    // masks needs the nesting limit checked here too, or it runs down the stack.
+    if depth > crate::MAX_EXPORT_DEPTH {
+        return None;
+    }
     let mut mask_px = Pixmap::new(w, h)?;
     let mut m2 = m.clone();
     m2.is_mask = false;

crates/render/src/gif_tests.rs

@@ -78,6 +78,20 @@ fn decoding_is_capped() {
     assert!(images::decode_frames(&huge).is_none());
 }
 
+#[test]
+fn a_large_partial_frame_plays_when_two_whole_frames_fit() {
+    // Canvas 4000 x 3000 (48 MB a frame, two fit the cap) with a 3500 x 2800 second frame: the
+    // decoder's canvas, composited output and partial frame together need more than the cap.
+    let mut out = Vec::new();
+    {
+        let mut enc = GifEncoder::new(&mut out);
+        enc.set_repeat(Repeat::Infinite).unwrap();
+        let frame = |w, h, c| Frame::from_parts(RgbaImage::from_pixel(w, h, image::Rgba(c)), 0, 0, Delay::from_numer_denom_ms(100, 1));
+        enc.encode_frames([frame(4000, 3000, RED), frame(3500, 2800, GREEN)]).unwrap();
+    }
+    assert_eq!(images::decode_frames(&out).map(|f| f.len()), Some(2));
+}
+
 #[test]
 fn the_first_frame_draws_unless_time_moves_on() {
     let mut d = Document::new("t");
@@ -98,3 +112,16 @@ fn the_first_frame_draws_unless_time_moves_on() {
     d.get_mut(id).unwrap().visible = false;
     assert!(images::animation_clock(&d, page, 0.15).is_none(), "hidden layers don't keep the presenter awake");
 }
+
+#[test]
+fn a_frame_descriptor_bigger_than_the_canvas_is_refused_before_it_is_allocated() {
+    // A 4 × 4 canvas whose first frame descriptor claims 16,383 × 16,383 (a gigabyte of RGBA):
+    // the decoder's limits refuse the frame buffer instead of allocating it.
+    let mut bytes = gif(&[(RED, 100), (GREEN, 100)], 4, 4);
+    let at = bytes.windows(9).position(|w| w == [0x2c, 0, 0, 0, 0, 4, 0, 4, 0]).expect("an image descriptor for a 4 × 4 frame");
+    let (w, h) = ((16_383u16).to_le_bytes(), (16_383u16).to_le_bytes());
+    bytes[at + 5..at + 9].copy_from_slice(&[w[0], w[1], h[0], h[1]]);
+    let start = std::time::Instant::now();
+    assert!(images::decode_frames(&bytes).is_none());
+    assert!(start.elapsed() < std::time::Duration::from_secs(5), "{:?}", start.elapsed());
+}

crates/render/src/glass.rs

@@ -1,9 +1,12 @@
 //! The glass effect: the backdrop seen through a pane whose edges curve down like a lens.
 //!
-//! Within `depth` of the outline the surface curves: the backdrop there is bent towards the inside
-//! (strongest at the very edge, `refraction` × `depth` far), each colour channel by a slightly
-//! different amount (`dispersion`, a rainbow fringe), and the rim catches the light: brightest
-//! where it faces `light_angle`, half as bright on the opposite side, spread wider by `splay`.
+//! Within `depth` of the outline the surface curves like a thick lens: the backdrop there is bent
+//! towards the inside, most a [`BEVEL`] in from the edge (`refraction` × `depth` far), falling off
+//! as the 3.5th power of the way out of the curve and gone `depth` further in, with a fifth as
+//! much on the bevel itself ([`bend_at`]). Each colour channel bends by a different amount
+//! (`dispersion`, a rainbow fringe: red furthest, blue least, each smeared along the bend), and the
+//! rim catches the light: brightest where it faces `light_angle`, half as bright on the opposite
+//! side, spread wider by `splay`.
 //! `frost` blurs the backdrop first. Distances to the outline come from an exact Euclidean
 //! distance transform of the shape's coverage.
 //!
@@ -162,6 +165,70 @@ fn smooth_normals(dist: &[f32], w: usize, h: usize, r: usize) -> Vec<(f32, f32)>
         .collect()
 }
 
+/// The bevel along a glass's edge (document units): where the bend eases off before the edge.
+pub(crate) const BEVEL: f64 = 1.0;
+
+/// How sharply the bend falls off going in: the 3.5th power of the way out of the curve.
+const PROFILE_EXP: f32 = 3.5;
+
+/// The furthest the backdrop moves, as a share of `depth`.
+const MAX_BEND: f32 = 0.999;
+
+/// The bend on the bevel itself, as a share of [`MAX_BEND`] × `depth` × `refraction`.
+const RIM_BEND: f32 = 0.2;
+
+/// Steps of the dispersion window: each channel is sampled this many times along the bend, weighted
+/// by a triangle (the two end steps weigh nothing and are skipped).
+const DISPERSION_STEPS: usize = 8;
+
+/// `x` from `a` to `b` as 0 to 1, clamped (a span under 1e-5 counts as 1e-5).
+fn lin(a: f32, b: f32, x: f32) -> f32 {
+    ((x - a) / (b - a).max(1e-5)).clamp(0.0, 1.0)
+}
+
+/// How far the backdrop moves at `x` pixels in from the edge, for a glass `depth` and [`BEVEL`]
+/// `bevel` deep (pixels) and `refraction` (0–1): a thick lens's profile, the most a bevel in from
+/// the edge, falling off as the 3.5th power of the way out of the curve to nothing `depth` further
+/// in, and a fifth as much on the bevel itself, eased between the two over its outer 70%.
+pub(crate) fn bend_at(x: f32, depth: f32, bevel: f32, refraction: f32) -> f32 {
+    // Past the curve (and the bevel's easing) nothing bends: the flat inside of the pane.
+    if x >= depth.max(1e-4) + bevel {
+        return 0.0;
+    }
+    let sd = -x;
+    let t = lin(-depth - bevel, -bevel, sd);
+    let most = MAX_BEND * depth;
+    let core = (t.powf(PROFILE_EXP) * depth * refraction).clamp(-most, most);
+    let rim = refraction * RIM_BEND * most;
+    let u = lin(-bevel - 1e-4, -0.3 * bevel, sd);
+    core + (rim - core) * u
+}
+
+/// The backdrop seen at pixel coordinates (`x`, `y`) moved by (`dx`, `dy`), its channels split by
+/// `k` (dispersion, 0–1): red moves up to `k` further, blue up to `k` less, each smeared along the
+/// move by a triangular window of [`DISPERSION_STEPS`]. One sample when `k` is too small to show.
+fn dispersed(frosted: &Pixmap, x: f32, y: f32, dx: f32, dy: f32, k: f32) -> [f32; 4] {
+    let at = |s: f32| sample(frosted, x + dx * s, y + dy * s);
+    if k < 0.001 {
+        let s = at(1.0);
+        return [s[0].min(s[3]), s[1].min(s[3]), s[2].min(s[3]), s[3]];
+    }
+    let last = (DISPERSION_STEPS - 1) as f32;
+    let (mut acc, mut sum) = ([0.0f32; 4], 0.0f32);
+    for i in 1..DISPERSION_STEPS - 1 {
+        let t = i as f32 / last - 0.5;
+        let w = 1.0 - (2.0 * t).abs();
+        let (r, g, b) = (at(1.0 + (t + 0.5) * k), at(1.0 + t * k), at(1.0 + (t - 0.5) * k));
+        acc[0] += r[0] * w;
+        acc[1] += g[1] * w;
+        acc[2] += b[2] * w;
+        acc[3] += r[3].max(g[3]).max(b[3]) * w;
+        sum += w;
+    }
+    let a = acc[3] / sum;
+    [(acc[0] / sum).min(a), (acc[1] / sum).min(a), (acc[2] / sum).min(a), a]
+}
+
 /// Bilinear sample of premultiplied `p` at pixel coordinates `(x, y)` (centres at +0.5), each
 /// channel 0..=255; transparent outside.
 fn sample(p: &Pixmap, x: f32, y: f32) -> [f32; 4] {
@@ -411,20 +478,20 @@ pub fn glass(g: &Glass, frame: EffectFrame<'_>) -> Option<Pixmap> {
     let EffectFrame { shape, back, pad, size: (w, h), xf, scale } = frame;
     let g = g.sanitized();
     let depth = (g.depth * scale).clamp(1.0, 1024.0);
+    let bevel = (BEVEL * scale).min(1024.0);
     let band = (depth * (0.15 + 0.35 * g.splay)).max(1.0);
     let reach = light_reach(band, g.light_intensity);
     let r = (depth * 0.1).clamp(1.0, 8.0) as usize;
     // Coverage with a margin, so wherever the layer is cut every distance the pixels read is
-    // exact: the bend's (within `depth`), the light's (within `reach`) and those the normals are
-    // smoothed from (2r + 1 further).
-    let m = depth.max(reach).ceil() as u32 + 4 * r as u32 + 4;
+    // exact: the bend's (within `depth` + `bevel`), the light's (within `reach`) and those the
+    // normals are smoothed from (2r + 1 further).
+    let m = (depth + bevel).max(reach).ceil() as u32 + 4 * r as u32 + 4;
     let (fields, shift) = shape_fields(shape, xf, w, h, m, r)?;
     let mut frosted = back.clone();
     fx::blur(&mut frosted, g.frost / 2.0 * scale);
     let ang = g.light_angle.to_radians();
     let light = (ang.sin() as f32, -ang.cos() as f32);
-    let bend_max = (g.refraction * depth) as f32;
-    let fringe = (g.dispersion * 0.25) as f32;
+    let (refraction, dispersion, bevel) = (g.refraction as f32, (g.dispersion * Glass::DISPERSION_SPREAD) as f32, bevel as f32);
     let power = (6.0 - 5.0 * g.splay) as f32;
     let (band, reach) = (band as f32, reach as f32);
     // The falloff, lowered by its value at `reach` and scaled back to 1 at the edge, so the light
@@ -441,19 +508,15 @@ pub fn glass(g: &Glass, frame: EffectFrame<'_>) -> Option<Pixmap> {
             if c <= 0.0 {
                 continue;
             }
-            let t = (d / depth).min(1.0);
-            let bend = bend_max * (1.0 - t) * (1.0 - t);
+            let bend = bend_at(d, depth, bevel, refraction);
             let (bx, by) = (x as f32 + pad as f32 + 0.5, y as f32 + pad as f32 + 0.5);
             let base = if bend == 0.0 {
-                // Nothing bends (past `depth`, or no refraction): the three channels' samples are
-                // at the same point, so one sample.
+                // Nothing bends (past `depth` + `bevel`, or no refraction): the channels' samples
+                // are at the same point, so one sample.
                 let s = sample(&frosted, bx, by);
                 [s[0].min(s[3]), s[1].min(s[3]), s[2].min(s[3]), s[3]]
             } else {
-                let at = |k: f32| sample(&frosted, bx + inward.0 * bend * k, by + inward.1 * bend * k);
-                let (rs, gs, bs) = (at(1.0 - fringe), at(1.0), at(1.0 + fringe));
-                let a = rs[3].max(gs[3]).max(bs[3]);
-                [rs[0].min(a), gs[1].min(a), bs[2].min(a), a]
+                dispersed(&frosted, bx, by, inward.0 * bend, inward.1 * bend, dispersion)
             };
             // The rim catches the light where it faces it, and half as much opposite. It fades out
             // by `reach` and is none past it, wherever the layer is cut.
@@ -479,6 +542,101 @@ pub fn glass(g: &Glass, frame: EffectFrame<'_>) -> Option<Pixmap> {
 mod tests {
     use super::*;
 
+    /// The bend at depth 20, refraction 0.8 and a 1-unit bevel, x units in from the edge: the
+    /// reference profile's values.
+    #[test]
+    fn the_bend_follows_the_thick_lens_profile() {
+        let table = [
+            (0.10, 3.1968),
+            (0.25, 3.1968),
+            (0.50, 6.8543),
+            (0.75, 11.4263),
+            (1.00, 15.9982),
+            (2.0, 13.3707),
+            (4.0, 9.0591),
+            (6.0, 5.8457),
+            (8.0, 3.5426),
+            (10.0, 1.9742),
+            (16.0, 0.1250),
+            (20.0, 0.0004),
+            (21.0, 0.0),
+            (40.0, 0.0),
+        ];
+        for (x, want) in table {
+            let got = bend_at(x, 20.0, 1.0, 0.8);
+            assert!((got - want).abs() < 1e-3, "x {x}: {got} vs {want}");
+        }
+        // No refraction, no bend; never more than 0.999 × depth, never outwards.
+        assert_eq!(bend_at(0.5, 20.0, 1.0, 0.0), 0.0);
+        for i in 0..400 {
+            let x = i as f32 * 0.1;
+            let b = bend_at(x, 20.0, 1.0, 1.0);
+            assert!((0.0..=0.999 * 20.0).contains(&b), "x {x}: {b}");
+        }
+        // A depth thinner than the bevel (zoomed far in) still gives numbers.
+        assert!(bend_at(0.5, 1.0, 8.0, 1.0).is_finite());
+        // `Glass::max_bend`, which sizes the backdrop read around a pane, bounds the whole bend.
+        for refraction in [0.3, 0.8, 1.0] {
+            let most = (0..800).map(|i| bend_at(i as f32 * 0.05, 20.0, 1.0, refraction as f32)).fold(0.0f32, f32::max);
+            let bound = Glass { refraction, depth: 20.0, dispersion: 0.0, ..Glass::default() }.max_bend();
+            assert!(f64::from(most) <= bound + 1e-4, "refraction {refraction}: {most} past {bound}");
+        }
+    }
+
+    /// Dispersion off is one sample at the moved point; on, the channels split along the move, red
+    /// further and blue less, and a flat backdrop stays flat.
+    #[test]
+    fn dispersion_splits_the_channels_along_the_bend() {
+        // A 40 × 1 ramp: red, green and blue all rise with x.
+        let mut p = Pixmap::new(40, 1).unwrap();
+        for (i, px) in p.data_mut().chunks_exact_mut(4).enumerate() {
+            let v = (i * 6) as u8;
+            px.copy_from_slice(&[v, v, v, 255]);
+        }
+        let one = sample(&p, 10.5 + 8.0, 0.5);
+        let off = dispersed(&p, 10.5, 0.5, 8.0, 0.0, 0.0);
+        assert_eq!(off, [one[0], one[1], one[2], one[3]]);
+        let on = dispersed(&p, 10.5, 0.5, 8.0, 0.0, 1.0);
+        assert!(on[0] > on[1] && on[1] > on[2], "{on:?}");
+        assert!((on[1] - one[1]).abs() < 1e-3, "green stays centred on the move: {on:?} vs {one:?}");
+        let mut flat = Pixmap::new(40, 1).unwrap();
+        flat.fill(tiny_skia::Color::from_rgba8(90, 120, 200, 255));
+        let f = dispersed(&flat, 10.5, 0.5, 8.0, 0.0, 1.0);
+        assert!(f.iter().zip([90.0, 120.0, 200.0, 255.0]).all(|(a, b)| (a - b).abs() < 1e-3), "{f:?}");
+        // One white pixel on black: only the weighted steps that reach it pick it up, red and green
+        // from opposite ends of their windows (the same amount), blue none.
+        let mut impulse = Pixmap::new(40, 1).unwrap();
+        impulse.fill(tiny_skia::Color::BLACK);
+        impulse.data_mut()[20 * 4..21 * 4].copy_from_slice(&[255, 255, 255, 255]);
+        let spread = dispersed(&impulse, 10.5, 0.5, 8.0, 0.0, 1.0);
+        assert!((spread[0] - 33.392857).abs() < 1e-3 && (spread[1] - 33.392857).abs() < 1e-3, "{spread:?}");
+        assert_eq!(spread[2], 0.0);
+    }
+
+    /// At full dispersion red's furthest step stays within `Glass::max_bend` of the pixel, all
+    /// along the bend, so the backdrop read around a pane covers it: one white pixel further out
+    /// than that is never seen.
+    #[test]
+    fn full_dispersion_reads_no_further_than_max_bend() {
+        let bound = Glass { refraction: 1.0, depth: 20.0, dispersion: 1.0, ..Glass::default() }.max_bend() as f32;
+        let k = Glass::DISPERSION_SPREAD as f32;
+        let mut furthest = 0usize;
+        for i in 0..100 {
+            let bend = bend_at(i as f32 * 0.25, 20.0, 1.0, 1.0);
+            for at in 0..40 {
+                let mut impulse = Pixmap::new(40, 1).unwrap();
+                impulse.fill(tiny_skia::Color::BLACK);
+                impulse.data_mut()[at * 4..at * 4 + 4].copy_from_slice(&[255, 255, 255, 255]);
+                let s = dispersed(&impulse, 0.5, 0.5, bend, 0.0, k);
+                if s[0].max(s[1]).max(s[2]) > 0.0 {
+                    furthest = furthest.max(at);
+                }
+            }
+        }
+        // A sample `o` pixels along picks up the pixel `at` while |o − at| < 1.
+        assert!(furthest > 0 && (furthest as f32) < bound + 1.0, "pixel {furthest} seen, past {bound}");
+    }
+
     #[test]
     fn distance_of_a_square() {
         let mut p = Pixmap::new(21, 21).unwrap();

crates/render/src/images.rs

@@ -293,12 +293,21 @@ pub fn decode_frames(bytes: &[u8]) -> Option<Vec<(Pixmap, f64)>> {
     if image::guess_format(bytes).ok()? != image::ImageFormat::Gif {
         return None;
     }
-    let dec = image::codecs::gif::GifDecoder::new(std::io::Cursor::new(bytes)).ok()?;
+    let mut dec = image::codecs::gif::GifDecoder::new(std::io::Cursor::new(bytes)).ok()?;
     let (w, h) = dec.dimensions();
     let frame_bytes = u64::from(w) * u64::from(h) * 4;
     if frame_bytes == 0 || w > MAX_SIDE || h > MAX_SIDE {
         return None;
     }
+    // A frame's own descriptor can ask for a far larger buffer than the canvas: the decoder
+    // reserves each frame and canvas buffer against these limits before allocating it.
+    let mut limits = image::Limits::default();
+    limits.max_image_width = Some(MAX_SIDE);
+    limits.max_image_height = Some(MAX_SIDE);
+    // The decoder charges its canvas, its composited output and the partial frame against this
+    // together, besides the frames kept (capped by `most` below): one frame of working room.
+    limits.max_alloc = Some(MAX_ANIMATION_BYTES.saturating_add(frame_bytes));
+    dec.set_limits(limits).ok()?;
     let most = (MAX_ANIMATION_BYTES / frame_bytes).min(MAX_FRAMES as u64) as usize;
     let mut out = Vec::new();
     for f in dec.into_frames().take(most) {

crates/render/src/mask_bounds_tests.rs

@@ -139,3 +139,24 @@ fn a_deep_nest_of_isolated_layers_stays_within_the_budget() {
     // The outer levels still draw (the innermost, past the budget, are left out).
     assert_ne!(&pix.data()[..4], &[255, 255, 255, 255]);
 }
+
+#[test]
+fn masks_nested_inside_masks_stop_at_the_nesting_limit() {
+    // A mask's content is drawn straight from `mask_pixels`, not through `draw_layer`, so a mask
+    // group inside a mask group inside… used to recurse past the limit and down the stack.
+    let mut d = Document::new("deep masks");
+    let p = d.first_page().unwrap();
+    let mut parent = p;
+    for _ in 0..2000 {
+        let g = d.create(parent, NodeKind::Group, "Masking group", 0.0, 0.0, 1.0, 1.0).unwrap();
+        let n = d.get_mut(g).unwrap();
+        n.is_mask = true;
+        n.mask_type = MaskType::Alpha;
+        parent = g;
+    }
+    shape(&mut d, parent, NodeKind::Rectangle, (0.0, 0.0, 100.0, 100.0), "2040E0");
+    shape(&mut d, p, NodeKind::Rectangle, (0.0, 0.0, 100.0, 100.0), "E04020");
+    let v = View { origin: (0.0, 0.0), scale: 1.0, width: 50, height: 50 };
+    let pix = render(&d, p, &v, false);
+    assert_eq!(pix.width(), 50);
+}

crates/svg/src/import.rs

@@ -103,11 +103,34 @@ pub(crate) struct Ctx<'a> {
     pattern_depth: usize,
     /// Tiles drawn so far, by pattern and scale (see [`paint`]'s `render_tile`).
     tiles: HashMap<(*const usvg::Pattern, u64), Option<paint::Tile>>,
+    /// The document image key of each embedded image's bytes already added, so an image a
+    /// pattern paints on many shapes is hashed once, not once per shape.
+    image_keys: HashMap<*const Vec<u8>, String>,
 }
 
 impl<'a> Ctx<'a> {
     pub(crate) fn new(doc: &'a mut Document) -> Self {
-        Ctx { doc, count: 0, anonymous: HashSet::new(), notes: BTreeSet::new(), fonts: None, pattern_depth: 0, tiles: HashMap::new() }
+        Ctx {
+            doc,
+            count: 0,
+            anonymous: HashSet::new(),
+            notes: BTreeSet::new(),
+            fonts: None,
+            pattern_depth: 0,
+            tiles: HashMap::new(),
+            image_keys: HashMap::new(),
+        }
+    }
+
+    /// [`add_image`] for `bytes`, once per distinct buffer.
+    pub(crate) fn image(&mut self, bytes: std::sync::Arc<Vec<u8>>, w: f64, h: f64) -> String {
+        if let Some(k) = self.image_keys.get(&std::sync::Arc::as_ptr(&bytes)) {
+            return k.clone();
+        }
+        let ptr = std::sync::Arc::as_ptr(&bytes);
+        let key = add_image(self.doc, bytes, w, h);
+        self.image_keys.insert(ptr, key.clone());
+        key
     }
 
     pub(crate) fn full(&self) -> bool {
@@ -605,7 +628,7 @@ fn image(cx: &mut Ctx, img: &usvg::Image, id: &str, parent: NodeId, base: Affine
     let size = img.size();
     let (iw, ih) = (f64::from(size.width()), f64::from(size.height()));
     let (transform, w, h) = place(world, Point::ZERO, iw, ih).unwrap_or((world, iw, ih));
-    let hash = add_image(cx.doc, bytes, iw, ih);
+    let hash = cx.image(bytes, iw, ih);
     let mut n = Node::new(cx.doc.alloc_id(), NodeKind::Rectangle, layer_name(id, "Image"), w, h);
     n.transform = transform;
     let mut fill = Paint::image(hash, ImageScaleMode::Fill);

crates/svg/src/import/budget.rs

@@ -44,6 +44,11 @@ fn inflate(data: &[u8], limit: usize) -> Result<Vec<u8>, String> {
     if out.len() > limit {
         return Err(format!("compressed SVG expands past {} MiB", limit >> 20));
     }
+    // usvg gunzips what it is handed, with no limit: one layer is unpacked here, within the
+    // budget, and what comes out must be the document itself.
+    if gzipped(&out) {
+        return Err("compressed SVG holds another compressed file, not a document".into());
+    }
     Ok(out)
 }
 
@@ -72,7 +77,15 @@ fn embedded(used: &Used, limits: &Limits, data: &[u8], opts: &Options) -> Option
         return None;
     }
     let left = limits.embedded.saturating_sub(used.bytes.load(Ordering::Relaxed));
-    let plain = inflate(data, left).ok()?;
+    let plain = match inflate(data, left) {
+        Ok(plain) => plain,
+        // What a refused document unpacked before it was refused was work too: it uses up what is
+        // left, so the next image can't repeat it.
+        Err(_) => {
+            used.bytes.fetch_add(left, Ordering::Relaxed);
+            return None;
+        }
+    };
     used.bytes.fetch_add(plain.len(), Ordering::Relaxed);
     if super::too_deep(&plain) {
         return None;

crates/svg/src/import/budget_tests.rs

@@ -111,3 +111,31 @@ fn linked_files_and_other_mime_types_stay_unresolved() {
     );
     assert_eq!(layers(data.as_bytes(), Limits::default()).unwrap(), layers(svg("").as_bytes(), Limits::default()).unwrap());
 }
+
+#[test]
+fn a_document_compressed_twice_is_refused_not_unpacked_again() {
+    // One gzip layer is unpacked within the budget; usvg would unpack a second one without any.
+    let twice = gzip(&gzip(svg(&" ".repeat(1 << 20)).as_bytes()));
+    let e = layers(&twice, Limits { document: 4 << 20, ..Limits::default() }).unwrap_err();
+    assert!(e.contains("another compressed file"), "{e}");
+    // Embedded, the same is dropped.
+    let inner = svg(r##"<rect width="10" height="10"/>"##);
+    let data = svg(&format!(
+        r##"<image width="10" height="10" xlink:href="data:image/svg+xml;base64,{}"/>"##,
+        base64::engine::general_purpose::STANDARD.encode(gzip(&gzip(inner.as_bytes())))
+    ))
+    .into_bytes();
+    assert_eq!(layers(&data, Limits::default()).unwrap(), layers(svg("").as_bytes(), Limits::default()).unwrap());
+}
+
+#[test]
+fn a_refused_embedded_bomb_uses_up_the_budget_for_the_images_after_it() {
+    let bomb = gzip(svg(&" ".repeat(1 << 20)).as_bytes());
+    let inner = svg(r##"<rect width="10" height="10"/>"##);
+    let image = |href: String| format!(r##"<image width="10" height="10" xlink:href="{href}"/>"##);
+    let bomb_uri = format!("data:image/svg+xml;base64,{}", base64::engine::general_purpose::STANDARD.encode(&bomb));
+    let data = svg(&format!("{}{}", image(bomb_uri).repeat(8), image(uri(inner.as_bytes())))).into_bytes();
+    let limits = Limits { embedded: 4096, ..Limits::default() };
+    let empty = layers(svg("").as_bytes(), limits).unwrap();
+    assert_eq!(layers(&data, limits).unwrap(), empty, "the first bomb spends the allowance; nothing after it unpacks");
+}

crates/svg/src/import/paint.rs

@@ -133,7 +133,7 @@ fn pattern(cx: &mut Ctx, pat: &usvg::Pattern, t: Target) -> Option<Paint> {
         let s = img.size();
         let (iw, ih) = (f64::from(s.width()), f64::from(s.height()));
         let b = figcraft_geom::transform_rect_bbox(m, Rect::new(0.0, 0.0, iw, ih));
-        (tile_rect.contains(b.origin()) && tile_rect.contains(Point::new(b.x1, b.y1))).then(|| (add_image(cx.doc, bytes, iw, ih), iw, ih, m))
+        (tile_rect.contains(b.origin()) && tile_rect.contains(Point::new(b.x1, b.y1))).then(|| (cx.image(bytes, iw, ih), iw, ih, m))
     });
     let (hash, iw, ih, content) = match lone {
         Some(l) => l,

crates/svg/src/import/structure_tests.rs

@@ -153,8 +153,9 @@ fn an_image_stretched_into_its_box_stays_stretched() {
 
 #[test]
 fn linked_files_are_never_read() {
-    let dir = std::env::temp_dir().join("figcraft-svg-linked");
-    std::fs::create_dir_all(&dir).unwrap();
+    let dir = std::env::temp_dir().join(format!("figcraft-svg-linked-{}", std::process::id()));
+    // `create_dir` refuses a directory or link someone else planted at this name.
+    std::fs::create_dir(&dir).unwrap();
     let png = dir.join("secret.png");
     std::fs::write(&png, base64::Engine::decode(&base64::engine::general_purpose::STANDARD, PNG).unwrap()).unwrap();
     let href = png.to_string_lossy().replace('\\', "/");

crates/text/src/fontdb_tests.rs

@@ -139,7 +139,10 @@ fn macos_font_assets_are_found_in_the_asset_store() {
             let _ = std::fs::remove_dir_all(&self.0);
         }
     }
-    let tmp = TempDir(std::env::temp_dir().join(format!("figcraft-font-assets-{}", std::process::id())));
+    // Created fresh: a directory or link already at this predictable name is refused, and not removed.
+    let root = std::env::temp_dir().join(format!("figcraft-font-assets-{}", std::process::id()));
+    std::fs::create_dir(&root).unwrap();
+    let tmp = TempDir(root);
     let store = tmp.0.join("AssetsV2");
     let fonts = store.join("com_apple_MobileAsset_Font7");
     let data = |kind: &std::path::Path| kind.join("0f1e2d.asset").join("AssetData");

crates/text/src/layout.rs

@@ -1698,11 +1698,22 @@ fn shape_segment(chars: &[char], seg: &Segment, face: &Arc<Face>, features: &[Fe
     }
     let (script_scale, script_shift) = synth.map_or((1.0, 0.0), |(_, up)| if up { face.superscript } else { face.subscript });
     let n = raw.len();
+    // Cluster end: the next larger cluster value, else the segment end. A glyph in the same
+    // cluster as the next one shares its end, so many glyphs of one cluster aren't rescanned.
+    let mut cends = vec![0usize; n];
+    for gi in (0..n).rev() {
+        let Some(&(_, cl, ..)) = raw.get(gi) else { continue };
+        let cl = cl as usize;
+        let shared = raw.get(gi + 1).filter(|r| r.1 as usize == cl).and_then(|_| cends.get(gi + 1).copied());
+        let cend = shared.unwrap_or_else(|| raw.iter().skip(gi + 1).map(|r| r.1 as usize).find(|c| *c > cl).unwrap_or(end).max(cl + 1));
+        if let Some(slot) = cends.get_mut(gi) {
+            *slot = cend;
+        }
+    }
     for gi in 0..n {
         let Some(&(gid, cl, xa, xo, yo)) = raw.get(gi) else { continue };
         let cl = cl as usize;
-        // Cluster end: the next larger cluster value, else the segment end.
-        let cend = raw.iter().skip(gi + 1).map(|r| r.1 as usize).find(|c| *c > cl).unwrap_or(end).max(cl + 1);
+        let cend = cends.get(gi).copied().unwrap_or(cl + 1);
         let last_in_cluster = raw.get(gi + 1).is_none_or(|r| r.1 as usize != cl);
         let ch = chars.get(cl).copied().unwrap_or(' ');
         let scale = if small_at(cl) { SMALL_CAP_SCALE } else { 1.0 } * script_scale;

crates/ui-egui/src/app/files.rs

@@ -6,12 +6,7 @@ use super::{
 impl FigApp {
     pub fn save_as_dialog(&mut self) {
         if self.services.downloads() {
-            if let Some(r) = self.run("file.saveAs", json!({"data": true}))
-                && self.download(r["name"].as_str().unwrap_or_default(), &r)
-            {
-                self.run("file.markSaved", json!({}));
-                dialogs::file_saved(self, &r);
-            }
+            self.save_download(None);
             return;
         }
         let Ok(name) = self.session.doc().map(|d| d.name.clone()) else { return };
@@ -43,6 +38,17 @@ impl FigApp {
         });
     }
 
+    /// Save by handing the file over as a download. `keep`: the name a Save of a host-opened
+    /// document keeps; `None` is a Save As, under the document's own name.
+    fn save_download(&mut self, keep: Option<&str>) {
+        if let Some(r) = self.run("file.saveAs", json!({"data": true}))
+            && self.download(keep.unwrap_or_else(|| r["name"].as_str().unwrap_or_default()), &r)
+        {
+            self.run("file.markSaved", json!({}));
+            dialogs::file_saved(self, &r);
+        }
+    }
+
     pub fn save(&mut self) {
         // A branch tab saves its main file.
         let tab = figcraft_engine::branches::file_tab(&self.session);
@@ -57,6 +63,9 @@ impl FigApp {
             if self.run("file.save", json!({})).is_some() {
                 self.toast(i18n::tr("Saved"));
             }
+        } else if let Some(name) = self.services.host_file().filter(|n| is_document_file(n)) {
+            // A host-opened document is saved as the file the host gave: the host updates that file.
+            self.save_download(Some(&name));
         } else {
             self.save_as_dialog();
         }
@@ -299,3 +308,8 @@ impl FigApp {
         failed
     }
 }
+
+/// A `.figcraft` file name: the document format a Save writes (a `.fig` is an export copy).
+fn is_document_file(name: &str) -> bool {
+    Path::new(name).extension().and_then(OsStr::to_str).is_some_and(|e| e.eq_ignore_ascii_case("figcraft"))
+}

crates/ui-egui/src/canvas/handles.rs

@@ -194,6 +194,33 @@ fn drag_id() -> Id {
     Id::unique("figcraft_handle_drag")
 }
 
+/// Whether a gradient handle or stop on the canvas is being dragged, the press that starts it
+/// included: those are the open colour picker's own controls, so the picker stays through the drag
+/// instead of taking the press for one outside it (#1852).
+pub fn gradient_dragging(ctx: &egui::Context) -> bool {
+    matches!(ctx.data(|d| d.get_temp::<Drag>(drag_id())), Some(Drag::Gradient { .. }))
+}
+
+/// Whether the document has a gesture open: a handle drag edits only inside its own.
+fn gesture_open(app: &FigApp) -> bool {
+    app.session.ds().is_ok_and(|d| d.interaction.is_some())
+}
+
+/// A handle drag whose button went up wherever the pointer was (off the canvas, over a panel, the
+/// colour picker or a ruler, outside the window) ends as a release on the handle would: the edit
+/// commits now, instead of waiting, uncommitted, to move the handle to wherever the pointer next
+/// presses. So does one whose gesture Escape or Undo closed under the held button: it stops there
+/// rather than editing on with no gesture open, an undo step a frame. True when a drag ended.
+pub fn end_released_drag(app: &mut FigApp, ctx: &egui::Context) -> bool {
+    let stashed = ctx.data(|d| d.get_temp::<Drag>(drag_id())).is_some();
+    if !stashed || (ctx.input(|i| i.pointer.primary_down()) && gesture_open(app)) {
+        return false;
+    }
+    let _ = app.session.commit_interaction();
+    ctx.data_mut(|d| d.remove::<Drag>(drag_id()));
+    true
+}
+
 /// The gradient being edited (single node, picker open on a gradient paint).
 fn gradient_target(app: &FigApp) -> Option<(NodeId, bool, usize, figcraft_color::Gradient)> {
     let Some(PickerTarget::Paint { fills, index, ids }) = &app.ui.picker else { return None };
@@ -525,6 +552,11 @@ pub fn input(app: &mut FigApp, ctx: &egui::Context, pos: Pos2) -> bool {
     });
     let dragging: Option<Drag> = ctx.data(|d| d.get_temp(drag_id()));
     if let Some(drag) = dragging {
+        // Escape or Undo closed the gesture under the held button: the drag is over.
+        if !gesture_open(app) {
+            ctx.data_mut(|d| d.remove::<Drag>(drag_id()));
+            return true;
+        }
         if down {
             apply(app, &drag, pos, shift);
             ctx.set_cursor_icon(egui::CursorIcon::Grabbing);

crates/ui-egui/src/canvas/input.rs

@@ -183,6 +183,8 @@ pub(super) fn input(app: &mut FigApp, ui: &mut Ui, resp: &egui::Response) -> boo
         if !ctx.input(|i| i.pointer.button_down(egui::PointerButton::Middle) || i.pointer.primary_down()) {
             app.canvas.middle_pan = None;
         }
+        // So is a handle drag.
+        crate::handles::end_released_drag(app, &ctx);
         return true;
     };
     // A press on the canvas gives the keyboard back to it (arrows nudge again).
@@ -230,6 +232,12 @@ pub(super) fn input(app: &mut FigApp, ui: &mut Ui, resp: &egui::Response) -> boo
         }
         return true;
     }
+    // A handle drag whose button went up ends first, wherever on the canvas the pointer is: over a
+    // ruler or a comment pin, which take the pointer below, or over something drawn above the
+    // canvas (the colour picker, a card). The handle had the press, so it has the release too.
+    if crate::handles::end_released_drag(app, &ctx) {
+        return false;
+    }
     if !app.canvas.dragging && (resp.hovered() || app.ui.comments.dragging()) && crate::comments::input(app, &ctx, pos) {
         return false;
     }

crates/ui-egui/src/colorpicker_selection_tests.rs

@@ -215,3 +215,160 @@ fn a_press_in_the_gradient_variable_picker_keeps_the_colour_picker_open() {
     assert!(u.app.ui.picker.is_some(), "the child variable picker is part of the interaction");
     u.button(at, false);
 }
+
+#[test]
+fn dragging_a_gradient_handle_on_the_canvas_keeps_the_picker_open() {
+    // #1852: the handles belong to the picker, so the press that starts a drag is not a press
+    // outside it: the picker and the handles stay, the drag is one undo step, and a press elsewhere
+    // on the layer still closes it.
+    let mut s = Session::new();
+    let a = NodeId(s.execute("shape.rectangle", &json!({"x": 100, "y": 100, "width": 200, "height": 200})).unwrap()["id"].as_u64().unwrap());
+    s.execute("fill.set", &json!({"id": a, "paint": {"type": "linearGradient", "stops": ["#ff0000", "#0000ff"]}})).unwrap();
+    s.execute("select.set", &json!({"ids": [a]})).unwrap();
+    let mut u = Ui::new(s);
+    let target = PickerTarget::Paint { fills: true, index: 0, ids: vec![a] };
+    u.app.open_picker(target.clone(), None);
+    for _ in 0..5 {
+        u.frame(vec![]);
+    }
+    assert_eq!(u.app.ui.picker, Some(target.clone()));
+    let depth = u.app.session.undo_depth().0;
+    let from_handle = |u: &Ui| match &u.app.session.doc().unwrap().node(a).unwrap().fills[0].kind {
+        figcraft_color::PaintKind::Gradient(g) => g.from,
+        _ => panic!("the fill is a gradient"),
+    };
+    assert_eq!(from_handle(&u), (0.5, 0.0), "a linear gradient starts at the top middle");
+    // Drag the start handle from the top middle of the layer to its left middle.
+    let from = u.app.to_screen(200.0, 100.0);
+    let to = u.app.to_screen(100.0, 200.0);
+    u.button(from, true);
+    assert_eq!(u.app.ui.picker, Some(target.clone()), "the press on the handle keeps the picker open");
+    for _ in 0..2 {
+        u.frame(vec![egui::Event::PointerMoved(to)]);
+    }
+    assert_eq!(u.app.ui.picker, Some(target.clone()), "and so does the drag");
+    let (x, y) = from_handle(&u);
+    assert!(x.abs() < 0.02 && (y - 0.5).abs() < 0.02, "the handle followed the pointer: ({x}, {y})");
+    u.button(to, false);
+    u.frame(vec![]);
+    assert_eq!(u.app.ui.picker, Some(target.clone()), "released, the picker is still open");
+    assert_eq!(u.app.session.undo_depth().0, depth + 1, "the drag is one undo step");
+    // A press on the layer away from its handles is still a press outside the picker.
+    let body = u.app.to_screen(250.0, 250.0);
+    u.button(body, true);
+    u.button(body, false);
+    u.frame(vec![]);
+    assert!(u.app.ui.picker.is_none(), "a plain canvas press closes it");
+}
+
+#[test]
+fn a_gradient_drag_released_off_the_canvas_ends_there() {
+    // A handle drag whose button goes up over the sidebar or over the picker itself ends there:
+    // the edit commits, the picker stays, and the next press on the canvas is a plain press (it
+    // closes the picker) rather than a move of the handle to wherever it landed.
+    for over in ["sidebar", "picker"] {
+        let mut s = Session::new();
+        let a = NodeId(s.execute("shape.rectangle", &json!({"x": 100, "y": 100, "width": 200, "height": 200})).unwrap()["id"].as_u64().unwrap());
+        s.execute("fill.set", &json!({"id": a, "paint": {"type": "linearGradient", "stops": ["#ff0000", "#0000ff"]}})).unwrap();
+        s.execute("select.set", &json!({"ids": [a]})).unwrap();
+        let mut u = Ui::new(s);
+        let target = PickerTarget::Paint { fills: true, index: 0, ids: vec![a] };
+        u.app.open_picker(target.clone(), None);
+        for _ in 0..5 {
+            u.frame(vec![]);
+        }
+        let depth = u.app.session.undo_depth().0;
+        let from_handle = |u: &Ui| match &u.app.session.doc().unwrap().node(a).unwrap().fills[0].kind {
+            figcraft_color::PaintKind::Gradient(g) => g.from,
+            _ => panic!("the fill is a gradient"),
+        };
+        u.button(u.app.to_screen(200.0, 100.0), true);
+        u.frame(vec![egui::Event::PointerMoved(u.app.to_screen(100.0, 200.0))]);
+        assert!(crate::handles::gradient_dragging(&u.ctx), "{over}: the handle is being dragged");
+        let spot = match over {
+            "sidebar" => u.app.ui.right_panel_rect.unwrap().center(),
+            _ => u.app.ui.picker_popover.as_ref().unwrap().rect.center(),
+        };
+        if over == "picker" {
+            assert!(u.app.canvas.rect.contains(spot), "the picker lies over the canvas");
+        } else {
+            assert!(!u.app.canvas.rect.contains(spot), "the sidebar is off the canvas");
+        }
+        u.button(spot, false);
+        u.frame(vec![]);
+        assert!(!crate::handles::gradient_dragging(&u.ctx), "{over}: the release ended the drag");
+        assert_eq!(u.app.ui.picker, Some(target.clone()), "{over}: the picker is still open");
+        assert_eq!(u.app.session.undo_depth().0, depth + 1, "{over}: the drag is one undo step");
+        let moved = from_handle(&u);
+        assert!(moved.0.abs() < 0.02 && (moved.1 - 0.5).abs() < 0.02, "{over}: the handle stayed where it was dragged: {moved:?}");
+        // The next press on the layer is a plain one: the handle stays put and the picker closes.
+        let body = u.app.to_screen(250.0, 250.0);
+        u.button(body, true);
+        u.frame(vec![]);
+        assert_eq!(from_handle(&u), moved, "{over}: a later press doesn't move the handle");
+        assert!(u.app.ui.picker.is_none(), "{over}: a later press closes the picker as any outside press does");
+        u.button(body, false);
+    }
+}
+
+/// A rectangle with a linear gradient fill, selected, its picker open and the canvas settled; a
+/// second layer drawn after it leaves an undo step that isn't the gradient's. Rulers on or off.
+fn gradient_ui(rulers: bool) -> Ui {
+    let mut s = Session::new();
+    if rulers {
+        s.execute("view.rulers", &json!({"on": true})).unwrap();
+    }
+    let a = NodeId(s.execute("shape.rectangle", &json!({"x": 100, "y": 100, "width": 200, "height": 200})).unwrap()["id"].as_u64().unwrap());
+    s.execute("fill.set", &json!({"id": a, "paint": {"type": "linearGradient", "stops": ["#ff0000", "#0000ff"]}})).unwrap();
+    s.execute("shape.rectangle", &json!({"x": 400, "y": 100, "width": 20, "height": 20})).unwrap();
+    s.execute("select.set", &json!({"ids": [a]})).unwrap();
+    let mut u = Ui::new(s);
+    u.app.open_picker(PickerTarget::Paint { fills: true, index: 0, ids: vec![a] }, None);
+    for _ in 0..5 {
+        u.frame(vec![]);
+    }
+    u
+}
+
+#[test]
+fn a_gradient_drag_released_over_a_ruler_ends_there() {
+    // The rulers take the pointer on the canvas before the handles do: the release still ends the
+    // drag, as one undo step, instead of leaving it waiting for the next press.
+    let mut u = gradient_ui(true);
+    let depth = u.app.session.undo_depth().0;
+    u.button(u.app.to_screen(200.0, 100.0), true);
+    u.frame(vec![egui::Event::PointerMoved(u.app.to_screen(100.0, 200.0))]);
+    assert!(crate::handles::gradient_dragging(&u.ctx), "the handle is being dragged");
+    let r = u.app.canvas.rect;
+    let ruler = egui::Pos2::new(r.min.x + 5.0, r.center().y);
+    assert!(!u.app.ui.picker_popover.as_ref().unwrap().rect.contains(ruler), "the ruler is not under the picker");
+    u.button(ruler, false);
+    assert!(!crate::handles::gradient_dragging(&u.ctx), "the release over the ruler ended the drag");
+    assert_eq!(u.app.session.undo_depth().0, depth + 1, "the drag is one undo step");
+}
+
+#[test]
+fn a_gradient_drag_whose_gesture_closes_under_the_held_button_stops_editing() {
+    // Escape (the picker closes and commits) or Undo ends the gesture while the button is still
+    // down: moving on edits nothing more, rather than adding an undo step every frame.
+    for close in ["escape", "undo"] {
+        let mut u = gradient_ui(false);
+        u.button(u.app.to_screen(200.0, 100.0), true);
+        u.frame(vec![egui::Event::PointerMoved(u.app.to_screen(100.0, 200.0))]);
+        assert!(crate::handles::gradient_dragging(&u.ctx), "{close}: the handle is being dragged");
+        if close == "escape" {
+            crate::colorpicker::close(&mut u.app);
+        } else {
+            assert!(u.app.session.undo().unwrap(), "{close}: there is a step to undo");
+        }
+        let depth = u.app.session.undo_depth().0;
+        let doc = u.app.session.doc().unwrap().clone();
+        for k in 1..=4 {
+            u.frame(vec![egui::Event::PointerMoved(u.app.to_screen(100.0 + 20.0 * f64::from(k), 200.0))]);
+        }
+        assert!(!crate::handles::gradient_dragging(&u.ctx), "{close}: the drag is over");
+        assert_eq!(u.app.session.undo_depth().0, depth, "{close}: no undo step a frame");
+        assert!(*u.app.session.doc().unwrap() == doc, "{close}: the gradient stays where the gesture left it");
+        u.button(u.app.to_screen(180.0, 200.0), false);
+    }
+}

crates/ui-egui/src/dialogs/credits.rs

@@ -247,6 +247,8 @@ const SORT_ARROW_W: f32 = 12.0;
 /// Padding inside each cell, on each side.
 const CELL_PAD: f32 = 6.0;
 const NAME_MIN_W: f32 = 110.0;
+/// The narrowest a credits column can be dragged.
+const MIN_COLUMN: f32 = 28.0;
 
 /// About ▸ Contributors: a name toggle, a sort, and the list as a grab bag or a table.
 pub fn contributors_ui(ui: &mut egui::Ui) {
@@ -341,13 +343,17 @@ fn column_width<'a>(ui: &egui::Ui, header: &str, cells: impl Iterator<Item = &'a
 }
 
 /// A credits table: columns of `widths`, the `None` one taking what the others leave (at least
-/// `flex_min`). The header stays put while the rows scroll, within `height` (header included). Too
-/// narrow for every column, it scrolls sideways rather than clip one.
+/// [`NAME_MIN_W`]). The header stays put while the rows scroll, within `height` (header included). Too
+/// narrow for every column, it scrolls sideways rather than clip one. Every
+/// column edge can be dragged, down to [`MIN_COLUMN`] (the `None` column to [`NAME_MIN_W`]): widening
+/// a column grows the table, as in a spreadsheet, and only then does it scroll sideways. When the
+/// window, a column's width or `flex_text` (the width the `None` column's text needs) changes, the
+/// columns go back to this fit, dropping any dragged widths.
 fn credits_table(
     ui: &mut egui::Ui,
     id: &str,
     widths: &[Option<f32>],
-    flex_min: f32,
+    flex_text: f32,
     height: f32,
     header: impl FnOnce(egui_extras::TableRow<'_, '_>),
     body: impl FnOnce(egui_extras::TableBody<'_>),
@@ -358,21 +364,31 @@ fn credits_table(
     // The table puts a row gap under its header.
     let body_h = (height - TABLE_HEADER_H - ui.spacing().item_spacing.y).max(TABLE_ROW_H);
     egui::ScrollArea::horizontal().id_salt((id, "h")).auto_shrink([false, true]).show(ui, |ui| {
-        let flex = (ui.available_width() - fixed).max(flex_min);
+        let flex = (ui.available_width() - fixed).max(NAME_MIN_W);
         // No gaps between cells: their padding spaces them, and the header rule runs unbroken.
         ui.spacing_mut().item_spacing.x = 0.0;
+        // The table keeps its own column widths, so a change in what they were fitted to has to clear
+        // them. Scrolling can nudge the available width, so this compares the clip rect, which scrolling
+        // never moves.
+        let fit = egui::Id::unique(("credits_fit", id));
+        let measured = (widths.to_vec(), flex_text, ui.clip_rect().width());
+        let refit = ui.data_mut(|d| d.get_temp::<(Vec<Option<f32>>, f32, f32)>(fit)).as_ref() != Some(&measured);
+        ui.data_mut(|d| d.insert_temp(fit, measured));
         let mut b = egui_extras::TableBuilder::new(ui)
             .id_salt(id)
             .striped(true)
-            .resizable(false)
+            .resizable(true)
             .auto_shrink([false, false])
             .min_scrolled_height(body_h)
             .max_scroll_height(body_h)
             .cell_layout(egui::Layout::left_to_right(egui::Align::Center));
+        if refit {
+            b.reset();
+        }
         for w in widths {
             b = b.column(match w {
-                Some(w) => egui_extras::Column::exact(*w),
-                None => egui_extras::Column::exact(flex).clip(true),
+                Some(w) => egui_extras::Column::initial(*w).at_least(MIN_COLUMN).clip(true),
+                None => egui_extras::Column::initial(flex).at_least(NAME_MIN_W).clip(true),
             });
         }
         b.header(TABLE_HEADER_H, header).body(body);
@@ -395,11 +411,13 @@ fn table(ui: &mut egui::Ui, list: &[&Contributor], v: &mut View, height: f32) {
     let t = Tokens::get(ui.ctx());
     let names = v.names;
     let widths = contributor_widths(ui, list);
+    let shown: Vec<String> = list.iter().map(|c| c.name(names)).collect();
+    let name_text = column_width(ui, SortKey::Name.label().1, shown.iter().map(String::as_str));
     credits_table(
         ui,
         "credits_table",
         &widths,
-        NAME_MIN_W,
+        name_text,
         height,
         |mut header| {
             for k in SortKey::ALL {
@@ -522,12 +540,13 @@ fn models_in(ui: &mut egui::Ui, models: &[Model], total_commits: u64) {
     let total = total_commits.max(models.iter().map(|m| m.commits).max().unwrap_or(0));
     let rows: Vec<[String; 6]> = models.iter().map(|m| model_cells(m, total)).collect();
     let widths = model_widths(ui, &rows);
+    let model_text = column_width(ui, tr(MODEL_HEADS[1]), rows.iter().filter_map(|r| r.get(1)).map(String::as_str));
     let numeric = |i: usize| i >= 3;
     credits_table(
         ui,
         "credits_models",
         &widths,
-        NAME_MIN_W,
+        model_text,
         table_height(ui, rows.len()),
         |mut header| {
             for (i, h) in MODEL_HEADS.iter().enumerate() {

crates/ui-egui/src/dialogs/credits/ui_tests.rs

@@ -267,3 +267,122 @@ fn the_about_window_draws_every_tab() {
         assert_eq!(app.ui.about_tab, tab);
     }
 }
+
+const WINDOW: f32 = 640.5;
+const WIDTHS: [Option<f32>; 3] = [None, Some(80.0), Some(80.0)];
+const NAME: f32 = 120.0;
+
+/// One frame of a table long enough to scroll, in a window `width` wide; the rects of its header cells.
+fn table_frame(ctx: &egui::Context, width: f32, widths: &[Option<f32>], name: f32, events: Vec<egui::Event>) -> Vec<Rect> {
+    let screen_rect = Some(Rect::from_min_size(egui::Pos2::ZERO, vec2(width, 300.0)));
+    let raw = egui::RawInput { screen_rect, events, ..Default::default() };
+    let mut cells = Vec::new();
+    let out = ctx.run_ui(raw, |ui| {
+        cells.clear();
+        credits_table(
+            ui,
+            "test",
+            widths,
+            name,
+            240.0,
+            |mut header| {
+                for _ in widths {
+                    header.col(|ui| cells.push(ui.max_rect()));
+                }
+            },
+            |body| {
+                body.rows(TABLE_ROW_H, 40, |mut row| {
+                    for _ in widths {
+                        row.col(|ui| {
+                            ui.label("x");
+                        });
+                    }
+                });
+            },
+        );
+    });
+    out.drop_without_applying_deltas();
+    cells
+}
+
+/// [`table_frame`] at the usual size.
+fn settled_frame(ctx: &egui::Context) -> Vec<Rect> {
+    table_frame(ctx, WINDOW, &WIDTHS, NAME, Vec::new())
+}
+
+/// A new context with the table open and settled, and the rects of its header cells.
+fn opened_table() -> (egui::Context, Vec<Rect>) {
+    let ctx = egui::Context::default();
+    settled_frame(&ctx);
+    let cells = settled_frame(&ctx);
+    (ctx, cells)
+}
+
+/// Drags a column's right edge (cells have no gap between them), then lets go.
+fn drag_edge(ctx: &egui::Context, cell: Rect, by: f32) {
+    let start = egui::pos2(cell.right(), cell.center().y);
+    let halfway = start + vec2(by / 2.0, 0.0);
+    let end = start + vec2(by, 0.0);
+    let moved = egui::Event::PointerMoved;
+    let button = |pos, pressed| egui::Event::PointerButton { pos, button: egui::PointerButton::Primary, pressed, modifiers: egui::Modifiers::NONE };
+    for event in [moved(start), button(start, true), moved(halfway), moved(end), button(end, false)] {
+        table_frame(ctx, WINDOW, &WIDTHS, NAME, vec![event]);
+    }
+}
+
+#[test]
+fn every_column_can_be_dragged_at_its_right_edge_and_stays_there() {
+    let (_, opened) = opened_table();
+    for (dragged, cell) in opened.iter().enumerate() {
+        let (ctx, _) = opened_table();
+        drag_edge(&ctx, *cell, -30.0);
+        settled_frame(&ctx);
+        let after = settled_frame(&ctx);
+        for (column, (was, now)) in opened.iter().zip(&after).enumerate() {
+            let want = if column == dragged { was.width() - 30.0 } else { was.width() };
+            assert!((now.width() - want).abs() < 1.0, "dragging column {dragged}: column {column} is {now:?}, was {was:?}");
+        }
+    }
+}
+
+#[test]
+fn a_changed_fit_replaces_the_column_widths() {
+    let (ctx, opened) = opened_table();
+    drag_edge(&ctx, opened[0], -30.0);
+    let longer_name = table_frame(&ctx, WINDOW, &WIDTHS, NAME + 80.0, Vec::new());
+    assert!((longer_name[0].width() - opened[0].width()).abs() < 1.0, "a longer name drops a dragged width: {longer_name:?}");
+    let wider = table_frame(&ctx, WINDOW, &[None, Some(200.0), Some(80.0)], NAME, Vec::new());
+    let widths: Vec<f32> = wider.iter().map(|c| c.width().round()).collect();
+    assert!(widths.ends_with(&[200.0, 80.0]), "a longer cell widens its column: {widths:?}");
+    // The table fills the window, which the layout rounds to whole points.
+    assert!(wider[2].right() <= WINDOW.ceil(), "the table still fits the window: {wider:?}");
+    let narrower = table_frame(&ctx, 400.0, &WIDTHS, NAME, Vec::new());
+    assert!(narrower[2].right() <= 400.0, "a narrower window refits the table: {narrower:?}");
+}
+
+#[test]
+fn scrolling_sideways_keeps_dragged_widths() {
+    let (ctx, opened) = opened_table();
+    drag_edge(&ctx, opened[0], 100.0);
+    settled_frame(&ctx);
+    let dragged = settled_frame(&ctx);
+    assert!((dragged[0].width() - opened[0].width() - 100.0).abs() < 1.0, "the drag took: {dragged:?}");
+    table_frame(&ctx, WINDOW, &WIDTHS, NAME, vec![egui::Event::PointerMoved(dragged[0].center())]);
+    let mut scrolled = false;
+    for delta in [-13.3, -27.77, -41.1, 30.6] {
+        let wheel = egui::Event::MouseWheel {
+            source: egui::MouseWheelSource::Unknown,
+            unit: egui::MouseWheelUnit::Point,
+            delta: vec2(delta, 0.0),
+            modifiers: egui::Modifiers::NONE,
+            phase: egui::TouchPhase::Move,
+        };
+        table_frame(&ctx, WINDOW, &WIDTHS, NAME, vec![wheel]);
+        for _ in 0..8 {
+            let cells = settled_frame(&ctx);
+            assert!((cells[0].width() - dragged[0].width()).abs() < 1.0, "scrolled by {delta}: {cells:?}");
+            scrolled |= cells[0].left() < dragged[0].left() - 1.0;
+        }
+    }
+    assert!(scrolled, "the wheel never moved the table sideways");
+}

crates/ui-egui/src/dialogs/plugins_ui.rs

@@ -138,7 +138,7 @@ pub(crate) fn save_file(app: &mut FigApp, data: &Value) {
     let shown = name.clone();
     app.pick_save(tr("Save file"), &name, &exts, move |app, path| {
         let file = path.file_name().map(|f| f.to_string_lossy().to_string()).unwrap_or(shown);
-        match std::fs::write(&path, &bytes) {
+        match figcraft_engine::file_access::write(&path, &bytes) {
             Ok(()) => app.toast(trf("Saved {name}", &[("name", &file)])),
             Err(_) => app.toast(tr("Couldn't save the file")),
         }

crates/ui-egui/src/field_tests.rs

@@ -667,11 +667,11 @@ fn the_glass_light_intensity_field_has_a_label() {
     u.ctx.data_mut(|d| d.insert_temp(Id::unique(("fx_open", 0usize)), true));
     u.frame(vec![]);
     let shapes = u.frame_output(vec![]).shapes;
-    let lead = u.ctx.read_response(Id::unique(("fx_gi", 0usize)).with("lead")).expect("the intensity field is shown").rect;
+    let lead = u.ctx.read_response(Id::unique(("fx", "lightIntensity", 0usize)).with("lead")).expect("the intensity field is shown").rect;
     let labels: Vec<(String, bool)> =
         painted_texts(&shapes).into_iter().filter(|(_, _, at)| lead.contains(at.center())).map(|(text, cut, _)| (text, cut)).collect();
     assert_eq!(labels, [("Intensity".to_string(), false)], "labelled, and not cut short");
-    let field = u.ctx.read_response(Id::unique(("fx_gi", 0usize)).with("field")).expect("its value").rect;
+    let field = u.ctx.read_response(Id::unique(("fx", "lightIntensity", 0usize)).with("field")).expect("its value").rect;
     assert_eq!(field.max.x - lead.min.x, GLASS_FIELD_W, "the width the next test measures against");
 }
 

crates/ui-egui/src/host_save_tests.rs

@@ -0,0 +1,60 @@
+//! In a page host the browser hands files to the host: a Save of the document the host opened goes
+//! out under the host's file name, a Save As under the document's own name.
+
+use std::sync::{Arc, Mutex};
+
+use figcraft_engine::Session;
+use serde_json::json;
+
+use crate::{FigApp, Services};
+
+type Saved = Arc<Mutex<Vec<String>>>;
+
+/// Services that save by downloads, with a document file the host opened.
+struct Host {
+    got: Saved,
+    file: Option<&'static str>,
+}
+
+impl Services for Host {
+    fn downloads(&self) -> bool {
+        true
+    }
+    fn download(&mut self, name: &str, _bytes: &[u8]) -> bool {
+        self.got.lock().unwrap().push(name.to_string());
+        true
+    }
+    fn host_file(&self) -> Option<String> {
+        self.file.map(str::to_string)
+    }
+}
+
+fn app(file: Option<&'static str>) -> (FigApp, Saved) {
+    let got = Saved::default();
+    let mut app = FigApp::new(Session::empty(), Box::new(Host { got: got.clone(), file }));
+    app.session.execute("file.new", &json!({"name": "Original"})).unwrap();
+    (app, got)
+}
+
+#[test]
+fn save_keeps_the_name_the_host_opened() {
+    let (mut app, got) = app(Some("client.figcraft"));
+    app.save();
+    assert_eq!(got.lock().unwrap().as_slice(), ["client.figcraft"]);
+}
+
+#[test]
+fn save_as_uses_the_document_s_own_name() {
+    let (mut app, got) = app(Some("client.figcraft"));
+    app.save_as_dialog();
+    assert_eq!(got.lock().unwrap().as_slice(), ["Original.figcraft"]);
+}
+
+#[test]
+fn without_a_host_file_or_for_a_copy_format_save_is_a_save_as() {
+    for file in [None, Some("design.json"), Some("export.fig")] {
+        let (mut app, got) = app(file);
+        app.save();
+        assert_eq!(got.lock().unwrap().as_slice(), ["Original.figcraft"], "{file:?}");
+    }
+}

crates/ui-egui/src/lib.rs

@@ -124,6 +124,8 @@ mod home_recents_tests;
 #[cfg(test)]
 mod home_tests;
 #[cfg(test)]
+mod host_save_tests;
+#[cfg(test)]
 mod idle_tests;
 #[cfg(test)]
 mod ime_tests;

crates/ui-egui/src/panels/right/effects.rs

@@ -108,7 +108,22 @@ pub(crate) fn effect_open(ctx: &egui::Context, i: usize) -> bool {
 
 /// A number field of effect `i` that can be bound to a variable (`effects/<i>/<prop>`).
 fn fx_field(app: &mut FigApp, ui: &mut Ui, ids: &[NodeId], i: usize, prop: &str, lead: Lead, value: f64, width: f32) -> Option<FieldEdit> {
-    crate::variable_ui::number_field(app, ui, ids, &format!("effects/{i}/{prop}"), Id::unique(("fx", prop, i)), lead, Some(value), "", width)
+    fx_field_in(app, ui, ids, i, prop, lead, Some(value), "", width)
+}
+
+/// [`fx_field`] showing `value` as given (a glass percentage) with `suffix` after it.
+fn fx_field_in(
+    app: &mut FigApp,
+    ui: &mut Ui,
+    ids: &[NodeId],
+    i: usize,
+    prop: &str,
+    lead: Lead,
+    value: Option<f64>,
+    suffix: &str,
+    width: f32,
+) -> Option<FieldEdit> {
+    crate::variable_ui::number_field(app, ui, ids, &format!("effects/{i}/{prop}"), Id::unique(("fx", prop, i)), lead, value, suffix, width)
 }
 
 /// Draw type-specific effect fields for shadows, blurs, noise, texture and glass, using live
@@ -290,29 +305,30 @@ fn effect_settings(app: &mut FigApp, ui: &mut Ui, ids: &[NodeId], i: usize, e: &
                     }
                 })
             };
+            // Each field takes a variable (`effects/<i>/<field>`), read as the field shows it:
+            // percentages for the 0–1 values, and the frost as `radius` (see `Glass::set_bound`).
             let pct = |v: f64| Some((v * 100.0).round());
             let unit = |v: f64| (v / 100.0).clamp(0.0, 1.0);
             row(ui, 32.0, |ui| {
-                let ed =
-                    widgets::number_field(ui, Id::unique(("fx_gl", i)), Lead::Text(tr("Light|glass")), Some(g.light_angle.round()), "°", half, 1.0);
+                let ed = fx_field_in(app, ui, ids, i, "lightAngle", Lead::Text(tr("Light|glass")), Some(g.light_angle.round()), "°", half);
                 edit(app, ed, &|v| with(&|gl| gl.light_angle = v.clamp(-180.0, 180.0)));
-                let ed = widgets::number_field(ui, Id::unique(("fx_gi", i)), Lead::Text(tr("Intensity")), pct(g.light_intensity), "%", half, 1.0);
+                let ed = fx_field_in(app, ui, ids, i, "lightIntensity", Lead::Text(tr("Intensity")), pct(g.light_intensity), "%", half);
                 edit(app, ed, &|v| with(&|gl| gl.light_intensity = unit(v)));
             });
             row(ui, 32.0, |ui| {
-                let ed = widgets::number_field(ui, Id::unique(("fx_gr", i)), Lead::Text(tr("Refraction")), pct(g.refraction), "%", half, 1.0);
+                let ed = fx_field_in(app, ui, ids, i, "refraction", Lead::Text(tr("Refraction")), pct(g.refraction), "%", half);
                 edit(app, ed, &|v| with(&|gl| gl.refraction = unit(v)));
-                let ed = widgets::number_field(ui, Id::unique(("fx_gd", i)), Lead::Text(tr("Depth")), Some(g.depth), "", half, 1.0);
+                let ed = fx_field_in(app, ui, ids, i, "depth", Lead::Text(tr("Depth")), Some(g.depth), "", half);
                 edit(app, ed, &|v| with(&|gl| gl.depth = v.clamp(1.0, 1000.0)));
             });
             row(ui, 32.0, |ui| {
-                let ed = widgets::number_field(ui, Id::unique(("fx_gs", i)), Lead::Text(tr("Dispersion")), pct(g.dispersion), "%", half, 1.0);
+                let ed = fx_field_in(app, ui, ids, i, "dispersion", Lead::Text(tr("Dispersion")), pct(g.dispersion), "%", half);
                 edit(app, ed, &|v| with(&|gl| gl.dispersion = unit(v)));
-                let ed = widgets::number_field(ui, Id::unique(("fx_gf", i)), Lead::Text(tr("Frost")), Some(g.frost), "", half, 1.0);
-                edit(app, ed, &|v| with(&|gl| gl.frost = v.clamp(0.0, 1000.0)));
+                let ed = fx_field_in(app, ui, ids, i, "radius", Lead::Text(tr("Frost")), Some(g.sanitized().frost), "", half);
+                edit(app, ed, &|v| with(&|gl| gl.frost = v.clamp(0.0, Glass::MAX_FROST)));
             });
             row(ui, 32.0, |ui| {
-                let ed = widgets::number_field(ui, Id::unique(("fx_gp", i)), Lead::Text(tr("Splay")), pct(g.splay), "%", half, 1.0);
+                let ed = fx_field_in(app, ui, ids, i, "splay", Lead::Text(tr("Splay")), pct(g.splay), "%", half);
                 edit(app, ed, &|v| with(&|gl| gl.splay = unit(v)));
             });
         }

crates/ui-egui/src/services.rs

@@ -24,6 +24,11 @@ pub trait Services {
     fn download(&mut self, _name: &str, _bytes: &[u8]) -> bool {
         false
     }
+    /// The document file a host page opened, where the app runs inside one (the browser's host
+    /// mode): a Save of that document keeps this name instead of the document's own.
+    fn host_file(&self) -> Option<String> {
+        None
+    }
     /// A folder to write several files into.
     fn pick_folder(&mut self, _title: &str) -> DialogFuture {
         Box::pin(std::future::ready(None))

crates/ui-egui/src/widgets/colorpicker.rs

@@ -978,7 +978,10 @@ pub fn show(app: &mut FigApp, ctx: &egui::Context) {
     // Sampling a colour from the canvas — the eyedropper this picker's own button started, or the
     // colour it just sampled — is the press, not a press outside: neither may close the picker.
     let picking = app.session.tool.pick_only || app.session.tool.picked.is_some();
-    pop = pop.close_on_outside(!picking);
+    // Nor may a press on the open gradient's handles or stops on the canvas: they are this picker's
+    // controls, and the canvas took the press before the picker drew (#1852).
+    let own = picking || crate::handles::gradient_dragging(ctx);
+    pop = pop.close_on_outside(!own);
     // Only the opening control is held out: any other sidebar or canvas press dismisses it.
     let mut held: Vec<Rect> = app.ui.picker_button.into_iter().collect();
     held.extend(crate::variable_ui::picker_rect(ctx));

crates/vectordrawable/src/walk.rs

@@ -24,6 +24,8 @@ pub(crate) struct Walker<'a> {
     opts: &'a VdOptions,
     warn: Warnings,
     names: std::collections::BTreeSet<String>,
+    /// The next suffix to try for each base name (names only get taken, so none before it is free).
+    next_suffix: std::collections::BTreeMap<String, usize>,
 }
 
 /// Every coordinate of `p` finite and within [`MAX_COORD`].
@@ -54,7 +56,7 @@ fn normal(b: BlendMode) -> bool {
 
 impl<'a> Walker<'a> {
     pub fn new(doc: &'a Document, opts: &'a VdOptions) -> Self {
-        Self { doc, opts, warn: Warnings::default(), names: Default::default() }
+        Self { doc, opts, warn: Warnings::default(), names: Default::default(), next_suffix: Default::default() }
     }
 
     /// Reports that the export drew nothing at all (named after `layer`).
@@ -78,12 +80,25 @@ impl<'a> Walker<'a> {
     fn unique(&mut self, name: &str) -> String {
         let base: String = name.chars().take(200).collect();
         let base = if base.trim().is_empty() { "layer".to_string() } else { base };
-        // Bounded: a set of n names leaves one of the first n + 1 candidates free.
-        let tries = self.names.len().saturating_add(1);
-        let name = (1..=tries)
-            .map(|k| if k == 1 { base.clone() } else { format!("{base}_{k}") })
-            .find(|n| !self.names.contains(n))
-            .unwrap_or_else(|| format!("{base}_{}", tries.saturating_add(1)));
+        let mut k = self.next_suffix.get(&base).copied().unwrap_or(1);
+        let mut stem = base.clone();
+        // Bounded: a set of n names leaves one of the first n + 1 candidates free. A counter
+        // that has run out (`usize::MAX`) continues from a longer stem instead of repeating.
+        let name = loop {
+            let candidate = if k == 1 { stem.clone() } else { format!("{stem}_{k}") };
+            if !self.names.contains(&candidate) {
+                k = k.saturating_add(1);
+                break candidate;
+            }
+            if k == usize::MAX {
+                stem = candidate;
+                k = 2;
+            } else {
+                k += 1;
+            }
+        };
+        let longer = stem.len() > base.len();
+        self.next_suffix.insert(base, if longer { usize::MAX } else { k });
         self.names.insert(name.clone());
         name
     }
@@ -404,3 +419,20 @@ impl<'a> Walker<'a> {
         }
     }
 }
+
+#[cfg(test)]
+mod unique_tests {
+    use super::*;
+
+    #[test]
+    fn an_exhausted_suffix_counter_still_finds_a_free_name() {
+        let (doc, opts) = (Document::new("File"), VdOptions::default());
+        let mut w = Walker::new(&doc, &opts);
+        w.next_suffix.insert("a".into(), usize::MAX);
+        w.names.insert(format!("a_{}", usize::MAX));
+        let first = w.unique("a");
+        let second = w.unique("a");
+        assert_ne!(first, second);
+        assert!(w.names.len() == 3 && w.names.contains(&first) && w.names.contains(&second));
+    }
+}

docs/components-parity.md

@@ -1,6 +1,6 @@
 # Components, variants, styles and variables parity
 
-> **Last reviewed:** 2026-10-10 · **Last updated:** 2026-11-01 · **Change:** minor (Delete on a layer inside an instance hides it as an override instead of being refused, as the help center says: "Figma will only toggle the layer's visibility instead of removing it"; library analytics list how many layers and files use each style and variable; SwiftUI and Compose code names a bound variable by its iOS or Android code syntax; library analytics count insertions and show insertions and detachments over the past 30 days, 90 days or year; a collection of this file can be extended (Extend collection on its row, `variable.extendCollection`), its extension following its edits at once, and extended collections extend again in the file; a typed or stored variable, collection or mode id names only the object with that id (#1613); colour variables can be calculated from other colours per mode — `{alpha}` replaces a colour's alpha, `{mix}` blends two — and follow them (#1280); stored variable and collection references keep their identity when another object is named like their id (follow-up to #1542); a component set's property rows fit the 240 px right panel: variant values wrap two to a line there and every + and − stays in view; opening a file contacts no team library server it names until you check it (#1097); an explicit variables file path (`variable.import`, the `variables` of `file.open` and `file.import`) is refused past 256 MiB or when it isn't a regular file, as the sibling `variables.json` already was (part of #1114); component properties keep the order they were made in when one is renamed, and Make slot asks for the slot's name first (#1536, #1537); components can't contain their own instances, directly or through others (#1084); the instance-swap menus have a search field (#1338); an instance-swap property's default menu scrolls (#1338); variables on a text style's fields from the style editor; instance-swap properties in the component playground; duplicating or Alt-dragging a main component makes an instance of it (#892); a bound colour variable's alpha applies once (#802); variables import reads `variables` outside `meta` and warns when it imports none (#790); variant properties reorder by drag; library files saved right after a read are read again; Hide when publishing note corrected; size and resizing overrides of layers inside instances (#731); variables export in the browser as a download; core editor leftovers: component playground, variables inside styles; layers and assets panels behaviour suite and fixes; extended collections tail; styles and variables behaviour suite and fixes; components behaviour suite and fixes; team libraries on the server, library usage and swapping a library; extended collections, variables import/export, gradient stops and variant properties bound to variables) · **Target:** Figma Design (desktop app 126.10.7)
+> **Last reviewed:** 2026-10-10 · **Last updated:** 2026-11-02 · **Change:** minor (glass effects take variables; Delete on a layer inside an instance hides it as an override instead of being refused, as the help center says: "Figma will only toggle the layer's visibility instead of removing it"; library analytics list how many layers and files use each style and variable; SwiftUI and Compose code names a bound variable by its iOS or Android code syntax; library analytics count insertions and show insertions and detachments over the past 30 days, 90 days or year; a collection of this file can be extended (Extend collection on its row, `variable.extendCollection`), its extension following its edits at once, and extended collections extend again in the file; a typed or stored variable, collection or mode id names only the object with that id (#1613); colour variables can be calculated from other colours per mode — `{alpha}` replaces a colour's alpha, `{mix}` blends two — and follow them (#1280); stored variable and collection references keep their identity when another object is named like their id (follow-up to #1542); a component set's property rows fit the 240 px right panel: variant values wrap two to a line there and every + and − stays in view; opening a file contacts no team library server it names until you check it (#1097); an explicit variables file path (`variable.import`, the `variables` of `file.open` and `file.import`) is refused past 256 MiB or when it isn't a regular file, as the sibling `variables.json` already was (part of #1114); component properties keep the order they were made in when one is renamed, and Make slot asks for the slot's name first (#1536, #1537); components can't contain their own instances, directly or through others (#1084); the instance-swap menus have a search field (#1338); an instance-swap property's default menu scrolls (#1338); variables on a text style's fields from the style editor; instance-swap properties in the component playground; duplicating or Alt-dragging a main component makes an instance of it (#892); a bound colour variable's alpha applies once (#802); variables import reads `variables` outside `meta` and warns when it imports none (#790); variant properties reorder by drag; library files saved right after a read are read again; Hide when publishing note corrected; size and resizing overrides of layers inside instances (#731); variables export in the browser as a download; core editor leftovers: component playground, variables inside styles; layers and assets panels behaviour suite and fixes; extended collections tail; styles and variables behaviour suite and fixes; components behaviour suite and fixes; team libraries on the server, library usage and swapping a library; extended collections, variables import/export, gradient stops and variant properties bound to variables) · **Target:** Figma Design (desktop app 126.10.7)
 
 Design systems are why teams adopt Figma. **Components: breadth ~96%, ready ~72%. Styles and
 variables: breadth ~95%, ready ~76% (estimated).** QA'd with a synthetic design system of ~300
@@ -67,7 +67,7 @@ updates with overrides kept: `library_tests.rs`, `components_scale_tests.rs`.
 | Modes: add, duplicate, rename, delete, set as default / reorder | done | layers on Auto follow a new default; explicit modes stay |
 | Deleting a bound variable or its collection | done | layers keep their last value and are unbound; aliases to it take its values and colour calculations reading it keep the colour they show |
 | Code syntax per platform (Web, iOS, Android) | done | generated CSS uses the Web name, SwiftUI the iOS one and Compose the Android one (a variable without one keeps its value there); in the variables JSON; ArkUI and Flutter have no platform of their own and write values |
-| Bindings: fills, strokes, effects, opacity, padding, gaps, sizes, radius, font family/style, font size/weight, line height, letter spacing, paragraph spacing/indent, text, visibility, layout grids, instance properties | done | type-checked per field; number variables fill text content; the Design panel's font family and font style menus start with Apply variable (string variables), and a bound one shows its variable in place of the menu; a colour variable bound to a solid paint brings its whole colour, alpha included, once (the paint's opacity restarts at 100% on binding, an opacity set while bound multiplies on top; unbinding moves the alpha back into the opacity) |
+| Bindings: fills, strokes, effects, opacity, padding, gaps, sizes, radius, font family/style, font size/weight, line height, letter spacing, paragraph spacing/indent, text, visibility, layout grids, instance properties | done | type-checked per field; glass fields too (light angle, intensity, refraction, depth, dispersion, frost and splay, percentages as the Design panel shows them); number variables fill text content; the Design panel's font family and font style menus start with Apply variable (string variables), and a bound one shows its variable in place of the menu; a colour variable bound to a solid paint brings its whole colour, alpha included, once (the paint's opacity restarts at 100% on binding, an opacity set while bound multiplies on top; unbinding moves the alpha back into the opacity) |
 | Explicit modes per frame, library collections' modes | done | stored variable and collection references resolve by exact id in export, library copies and swaps, imported aliases, alias deletion and cycle checks, Dev Inspect, the library mode picker and prototype playback; a collection or variable named like another's id no longer stands in for it there |
 | Gradient stops and variant properties bound to variables | done | a stop's binding follows it when earlier stops are removed |
 | Extended collections | done | this file's collections (Extend collection on a collection's row; following its edits at once, chains included) and library collections, including a library's own extended collections (chains through libraries); overrides per mode with reset; follow library updates, variables new to the library collection being an update of their own; modes inherited. Checked with synthetic libraries only ([gaps](gaps.md) #14) |
@@ -78,6 +78,7 @@ updates with overrides kept: `library_tests.rs`, `components_scale_tests.rs`.
 
 | Date | Change | Summary |
 |---|---|---|
+| 2026-11-02 | minor | M3, #1885: glass effects take variables, as the reference tool's do: its light angle, intensity, refraction, depth, dispersion, frost and splay bind to number variables on a layer (`variable.bind`, `effects/<i>/<lightAngle\|lightIntensity\|refraction\|depth\|dispersion\|radius\|splay>`, `radius` being the frost) and in an effect style (`style.bind`), and the Design panel's glass fields take a variable like the shadow and blur fields. A variable reads as the field shows it: intensity, refraction, dispersion and splay in percent. Tests: `binding_lists_tests::glass_fields_take_number_variables`, `effects_tests::glass_fields_take_bound_numbers_as_the_panel_shows_them`. Grade unchanged. |
 | 2026-11-01 | patch | M3: Delete on a layer inside an instance hides it (an override) instead of being refused ("You can't delete a layer or object from an instance. If you try, Figma will only toggle the layer's visibility instead of removing it", Guide to auto layout); `edit.delete` reports those ids under `hidden`, the structure and the main component stay as they were, one undo step; deleting the instance itself still removes it. Found by a documentation audit of the auto layout page. Test: `components_behaviour_tests::deleting_a_layer_inside_an_instance_hides_it_instead` (the refusal row for it is gone from `what_instances_cannot_override_is_refused`). Numbers unchanged |
 | 2026-10-31 | minor | M3, gap 10: library analytics cover styles and variables. A file reports how many of its layers use each of a library's styles and variables, and Show usage (`library.usage`) lists them beside the components, by a Type choice, with their layers and files. Layers inside instances count for their component. Insertions, detachments and modes aren't counted for them yet. Numbers unchanged. Tests: `library_assets_tests`. |
 | 2026-10-31 | minor | M6: as the help center describes code syntax, Dev Mode's SwiftUI and Compose code now writes a bound variable's iOS or Android code syntax in place of its value, as CSS already wrote the Web one: fills, strokes and their weight, sizes, corner radius, gaps, padding, opacity, the font family and size and the characters. A variable with no code syntax for the platform keeps the value, since a name made up here wouldn't exist in the code it lands in. ArkUI and Flutter have no code syntax platform and are unchanged. Test: `variables_behaviour_tests::swiftui_and_compose_name_variables_by_their_code_syntax`. Numbers unchanged. Grade unchanged |

docs/target-app-parity.md

@@ -1,6 +1,6 @@
 # FigCraft parity with Figma
 
-> **Last reviewed:** 2026-10-10 · **Last updated:** 2026-11-01 · **Change:** minor (bulleted lists use the same bullet at every level of indentation, as the help center says, instead of a white bullet and a square at the deeper levels; typing `1)` and a space at the start of a paragraph starts a numbered list, as `1.` does, both being the help center's creation characters; a link on text is underlined by default, as the help center says, and Underline takes the underline off while the link stays; a Dash cap setting (none, round or square) on Dash and Custom strokes, drawn on both ends of every dash; gap 6: widgets draw lines and SVG pictures (plugin API 6); gap 6: a widget opens its plugin's panel (plugin API 5), whose callbacks redraw it; the browser build uses the fonts installed on the computer once asked, each read when text uses it (#1051); plugin widgets have hover styles: a layer's `hover` fill, stroke, opacity or text colour shows while the pointer is over it (gap 6); Thai, Lao, Khmer and Burmese lines break between words (#1219); MCP and control calls name their document (#998); shadows of images with transparent pixels follow their alpha (#1289); Arabic draft catalog; truncated text fills its last line before the ellipsis and keeps truncating when resized; auto-height text with max lines (#1375, #1376, #1377), numbers unchanged; plugin widgets take text input and a property menu (plugin API 4); boards: templates and tables; boards: a shared timer and voting sessions; boards: the dot grid, connector ends dragged to re-attach, curved connectors; `.sketch` import, best effort: import/export breadth 86% → 87%, file formats 60% → 61%, headline numbers unchanged; Canvas & navigation's remaining work no longer lists outline mode's Include hidden layers and Include object bounds; boards: area 22 (weight 0, outside the weighted sum); CJK line breaking: JIS X 4051's line-start and line-end sets completed with the halfwidth small kana, the halfwidth and spacing (semi-)voiced sound marks, iteration marks 〱–〵 and the halfwidth parentheses; Turkish reviewed, Czech and Indonesian drafts, the Japanese draft completed; reviewed Russian catalog and integer plurals; vector edit mode regions: hover hatch, selection and drag; plugin log byte/count limits (#191); core editor leftovers: component playground, auto gap handles, variables inside styles, inner shadows and background blur on groups, command-made text readable on dark pages, a one-step frame/group convert, delays on mouse triggers and manual overlay offsets, wrapped-line alignment; starter templates, a Templates tab and Getting started tips on the home screen: essentials ~57% → ~59%; everyday editing partials: number fields, outline options, Hide when publishing, cursors, panel widths, dark pages, numbers unchanged but menu breadth 211/211; text box sizes measured against documents re-saved by other software: whole-pixel line heights, advances on a 1024-per-em grid, letter spacing between glyphs only, numbers unchanged; .fig export checked by opening written files in other software, numbers unchanged; a public figcraft-server: open hosting, owner tokens, per-address limits, idle expiry, moderation, install.sh; experimental .fig export; keyboard shortcut parity suite and bindings; Simplified Chinese draft catalog; Latin American Spanish overlay; prototyping tail: gamepad triggers, widgets in prototypes, mode lookups; plugin directory on figcraft-server; Japanese and Korean draft catalogs and CJK UI fonts; plugin widgets and the plugin panel tail; French, German and Brazilian Portuguese draft catalogs; cursor chat and spotlight in live sessions; layers and assets panels behaviour suite and fixes; vector multi-edit and edit tail; dev resources links; extended collections tail; branch version history and finer list merges; headline percentages recomputed from the area table: feature breadth ~84%, core ~94%, mainstream ~50%; text lists, hanging punctuation and decoration styles; comments and version history behaviour suite and fixes; canvas navigation, guides and grids behaviour suite and fixes; export and inspect behaviour suite and fixes; .fig import: editable vector networks and more layer kinds; shapes and vector behaviour suite and fixes; paint and effects behaviour suite and fixes; frames, groups, sections and masks behaviour suite and fixes; styles and variables behaviour suite and fixes; prototyping behaviour suite and fixes; components behaviour suite and fixes; embedded image colour profiles; layers panel keyboard: F2 rename, Shift+F10 context menu, keyboard box selection, 10k-layer QA; per-side stroke weight variables; text behaviour suite: CJK line breaking, metrics, vertical trim; selection and transform behaviour suite and fixes; `.fig` import, best effort; auto layout behaviour suite and fixes; Display P3: gamut warning and soft-proof (true P3 blocked upstream); several windows; localization layer with a draft Spanish catalog; hostingLine truncated
+> **Last reviewed:** 2026-10-10 · **Last updated:** 2026-11-02 · **Change:** minor (glass bends with a thick-lens profile and splits its colours over 8 steps, measured against the reference tool; bulleted lists use the same bullet at every level of indentation, as the help center says, instead of a white bullet and a square at the deeper levels; typing `1)` and a space at the start of a paragraph starts a numbered list, as `1.` does, both being the help center's creation characters; a link on text is underlined by default, as the help center says, and Underline takes the underline off while the link stays; a Dash cap setting (none, round or square) on Dash and Custom strokes, drawn on both ends of every dash; gap 6: widgets draw lines and SVG pictures (plugin API 6); gap 6: a widget opens its plugin's panel (plugin API 5), whose callbacks redraw it; the browser build uses the fonts installed on the computer once asked, each read when text uses it (#1051); plugin widgets have hover styles: a layer's `hover` fill, stroke, opacity or text colour shows while the pointer is over it (gap 6); Thai, Lao, Khmer and Burmese lines break between words (#1219); MCP and control calls name their document (#998); shadows of images with transparent pixels follow their alpha (#1289); Arabic draft catalog; truncated text fills its last line before the ellipsis and keeps truncating when resized; auto-height text with max lines (#1375, #1376, #1377), numbers unchanged; plugin widgets take text input and a property menu (plugin API 4); boards: templates and tables; boards: a shared timer and voting sessions; boards: the dot grid, connector ends dragged to re-attach, curved connectors; `.sketch` import, best effort: import/export breadth 86% → 87%, file formats 60% → 61%, headline numbers unchanged; Canvas & navigation's remaining work no longer lists outline mode's Include hidden layers and Include object bounds; boards: area 22 (weight 0, outside the weighted sum); CJK line breaking: JIS X 4051's line-start and line-end sets completed with the halfwidth small kana, the halfwidth and spacing (semi-)voiced sound marks, iteration marks 〱–〵 and the halfwidth parentheses; Turkish reviewed, Czech and Indonesian drafts, the Japanese draft completed; reviewed Russian catalog and integer plurals; vector edit mode regions: hover hatch, selection and drag; plugin log byte/count limits (#191); core editor leftovers: component playground, auto gap handles, variables inside styles, inner shadows and background blur on groups, command-made text readable on dark pages, a one-step frame/group convert, delays on mouse triggers and manual overlay offsets, wrapped-line alignment; starter templates, a Templates tab and Getting started tips on the home screen: essentials ~57% → ~59%; everyday editing partials: number fields, outline options, Hide when publishing, cursors, panel widths, dark pages, numbers unchanged but menu breadth 211/211; text box sizes measured against documents re-saved by other software: whole-pixel line heights, advances on a 1024-per-em grid, letter spacing between glyphs only, numbers unchanged; .fig export checked by opening written files in other software, numbers unchanged; a public figcraft-server: open hosting, owner tokens, per-address limits, idle expiry, moderation, install.sh; experimental .fig export; keyboard shortcut parity suite and bindings; Simplified Chinese draft catalog; Latin American Spanish overlay; prototyping tail: gamepad triggers, widgets in prototypes, mode lookups; plugin directory on figcraft-server; Japanese and Korean draft catalogs and CJK UI fonts; plugin widgets and the plugin panel tail; French, German and Brazilian Portuguese draft catalogs; cursor chat and spotlight in live sessions; layers and assets panels behaviour suite and fixes; vector multi-edit and edit tail; dev resources links; extended collections tail; branch version history and finer list merges; headline percentages recomputed from the area table: feature breadth ~84%, core ~94%, mainstream ~50%; text lists, hanging punctuation and decoration styles; comments and version history behaviour suite and fixes; canvas navigation, guides and grids behaviour suite and fixes; export and inspect behaviour suite and fixes; .fig import: editable vector networks and more layer kinds; shapes and vector behaviour suite and fixes; paint and effects behaviour suite and fixes; frames, groups, sections and masks behaviour suite and fixes; styles and variables behaviour suite and fixes; prototyping behaviour suite and fixes; components behaviour suite and fixes; embedded image colour profiles; layers panel keyboard: F2 rename, Shift+F10 context menu, keyboard box selection, 10k-layer QA; per-side stroke weight variables; text behaviour suite: CJK line breaking, metrics, vertical trim; selection and transform behaviour suite and fixes; `.fig` import, best effort; auto layout behaviour suite and fixes; Display P3: gamut warning and Line truncated
 
 The authoritative assessment of how close FigCraft is to Figma Design. [`ROADMAP.md`](../ROADMAP.md)
 summarizes it; [`gaps.md`](gaps.md) is the ranked work list; the measured menu checklist is
@@ -648,6 +648,7 @@ Carried over from the ROADMAP's "Shipped so far" (2026-10-10). The test count th
 
 | Date | Change | Summary |
 |---|---|---|
+| 2026-11-02 | minor | M3, #1885: glass bends the backdrop with the reference tool's thick-lens profile (most a 1-unit bevel in from the edge, falling off as the 3.5th power of the way out of the curve to nothing `depth` further in) and splits its colours over 8 steps, red and blue 0.16 of the bend apart at 100% dispersion. Measured against the reference tool on synthetic files at 2×: the black band a pane pulls to its edge ends within 3 px of the reference tool's, and red and blue part 2.27 px at 50% dispersion and 4.66 px at 100% (2.38 and 4.69 there). Tests: `glass::tests::the_bend_follows_the_thick_lens_profile`, `glass::tests::dispersion_splits_the_channels_along_the_bend`. Grade unchanged. |
 | 2026-11-01 | patch | M4: bulleted lists draw the same bullet at every level of indentation ("Figma bullets will keep the same styling at all levels of indentation", Create bulleted and numbered lists); the deeper levels drew a white bullet and a small square, pinned as silent before. Numbered levels (1., a., i.) are unchanged. Found by a documentation audit of the text rules. Test: `tail_tests::list_numbering_by_level` (the bullets row). Numbers unchanged |
 | 2026-11-01 | patch | M4: typing `1)` followed by a space at the start of a plain paragraph starts a numbered list, as `1.` already did ("Enter one of the creation characters below followed by a Space: 1. 1)", Create bulleted and numbered lists). Found by a documentation audit of the text rules. Test: `text_tail_tests::typing_a_creation_character_and_a_space_starts_a_list`. Numbers unchanged |
 | 2026-11-01 | patch | M4: a link made with `text.link` (Cmd/Ctrl+K, Shift+Cmd/Ctrl+U) underlines the linked text unless it has a decoration of its own ("Links are styled with an underline by default. Use the keyboard shortcut to remove the underline", Add links to text); Underline (Cmd/Ctrl+U) takes the underline off and the link stays. Found by a documentation audit of the text rules. Test: `text_behaviour_tests::a_link_is_underlined_by_default_and_underline_takes_it_off`. Numbers unchanged |

docs/ui-parity.md

@@ -1,6 +1,6 @@
 # UI and interaction parity
 
-> **Last reviewed:** 2026-10-10 · **Last updated:** 2026-11-02 · **Change:** minor (the Fill section of a text whose characters were coloured differently while editing shows mixed content, characters that all share fills the layer doesn't have show those, and a layer-level fill edit reaches every character (#1856); a click with the Bend tool on a sharp point curves it, its handles along the line between its neighbours, as Edit vector layers says (#1875); wrap style: Auto, Balance and Pretty on a text layer decide where its lines break, as Explore text properties says (#1827), with the Type settings control, `text.wrapStyle`, `node.set wrapStyle`, inspect and the CSS `text-wrap`; Backspace or Delete at the start of a list item keeps the item's indentation level, as the lists article says; max lines on auto-width text keep it auto width, hugging that many lines, as the text properties article says; superscript and subscript are synthesised where the font has no glyphs for them, from the standard glyphs shrunk and shifted by the font's OS/2 metrics, and a run mixing available and unavailable glyphs is synthesised whole, as Explore text properties says (#1828); Alt+Enter while editing text opens the link at the caret, as the accessibility page documents; Minimize, by its shortcut or the button by the file name, collapses the navigation bar and both sidebars as the help center says, with the right sidebar back while something is selected (#1835); the interface size keys of the help center's accessibility page: Cmd/Ctrl+Shift+Alt with =, - and 0 step the interface through the Preferences sizes and back to the system's size; Cmd/Ctrl+Alt+arrows rotate the selection a degree at a time, 15 with Shift, as the help center's accessibility page says; they resized before; the Layers panel answers Ctrl+1 as well as Alt+1 on Windows and Linux, the two keys the help center gives it; the colour picker's Image tab shows a placeholder and Upload from computer, an asset preview, and a file dropped on it replaces the image, keeping the fill mode, crop and position (#1682); the keyboard's Menu key opens the context menu, as Shift+F10 does; the eyedropper with Cmd/Ctrl+Shift makes a colour style or variable of what it picks; sidebar number and text fields keep their text vertically centered when focused, including typography spacing; with the pen out, Enter or a double-click ends the path and edits the vector with the Move tool instead of drawing on (#1430); the Actions palette offers only commands that run from it, and no second row reading like a menu item: Place image opens the file dialog (#1574); Preferences ▸ Scroll wheel zoom: a mouse wheel zooms the canvas about the pointer and Cmd/Ctrl+wheel scrolls (#1390); boolean operations refuse input past their caps, and a boolean group past them draws without its result (#1104); the selection and hover outlines of rounded rectangles and frames follow their corners (#1506); colour picker review fixes for text undo, fitted sidebars, moving controls and gradient variables; Corner smoothing: an original icon and the shared number-field drag gesture, preserving fractional baselines; guides snap to layers when dragged; Crop image: Object ▸ Crop image, the right-click menu and the image fill row enter crop mode (`image.crop`, #1464); the Design panel's sections on one grid — 16 / 8 margins, 88 + 8 + 88 + 8 + 24 columns, 24 pt rows, 4 pt between a row's buttons (#858); the toolbar on one 32 pt grid, without its Resources button (#1210); colour picker LCH and OKLCH models; an XML (Android Vector Drawable) export format; Context menus: the Menu key reaches egui 0.37 but is unbound (row done → partial); the Text on a path tool; board tool keys pinned; community fixes: the text box by dragging, the font picker keys, the pen path on leaving Design, a still canvas in vector edit mode, a scrolling pages list, colour emoji, readable new text in frames, system theme on first run; the Small caps sample in Type settings drawn from capitals; recent files as cards; vector edit mode: hovering, hatching, selecting and dragging filled regions; home screen: Templates tab, first-run templates and Getting started tips; number fields: scrub rates, arrow steps, arithmetic with brackets, relative edits of mixed values; outline mode's hidden layers and object bounds; Hide when publishing; cursors per tool and modifier; panel widths; dark pages for files made in the dark theme; drag threshold and double-clicks into text in groups; rotation origin on Alt+R and placing with Enter: no documented shortcut missing; keyboard shortcut parity suite and bindings; cursor chat and spotlight in live sessions; layers and assets panels behaviour suite and fixes; vector multi-edit and the vector edit tail; canvas navigation, guides and grids behaviour suite and fixes; shapes and vector behaviour suite and fixes; paint and effects behaviour suite and fixes; frames, groups, sections and masks behaviour suite and fixes;Line truncated
+> **Last reviewed:** 2026-10-10 · **Last updated:** 2026-11-04 · **Change:** minor (the Fill section of a text whose characters were coloured differently while editing shows mixed content, characters that all share fills the layer doesn't have show those, and a layer-level fill edit reaches every character (#1856); a press on the open gradient's handles or stops on the canvas keeps the colour picker open through the drag, as its own control (#1852); a click with the Bend tool on a sharp point curves it, its handles along the line between its neighbours, as Edit vector layers says (#1875); wrap style: Auto, Balance and Pretty on a text layer decide where its lines break, as Explore text properties says (#1827), with the Type settings control, `text.wrapStyle`, `node.set wrapStyle`, inspect and the CSS `text-wrap`; Backspace or Delete at the start of a list item keeps the item's indentation level, as the lists article says; max lines on auto-width text keep it auto width, hugging that many lines, as the text properties article says; superscript and subscript are synthesised where the font has no glyphs for them, from the standard glyphs shrunk and shifted by the font's OS/2 metrics, and a run mixing available and unavailable glyphs is synthesised whole, as Explore text properties says (#1828); Alt+Enter while editing text opens the link at the caret, as the accessibility page documents; Minimize, by its shortcut or the button by the file name, collapses the navigation bar and both sidebars as the help center says, with the right sidebar back while something is selected (#1835); the interface size keys of the help center's accessibility page: Cmd/Ctrl+Shift+Alt with =, - and 0 step the interface through the Preferences sizes and back to the system's size; Cmd/Ctrl+Alt+arrows rotate the selection a degree at a time, 15 with Shift, as the help center's accessibility page says; they resized before; the Layers panel answers Ctrl+1 as well as Alt+1 on Windows and Linux, the two keys the help center gives it; the colour picker's Image tab shows a placeholder and Upload from computer, an asset preview, and a file dropped on it replaces the image, keeping the fill mode, crop and position (#1682); the keyboard's Menu key opens the context menu, as Shift+F10 does; the eyedropper with Cmd/Ctrl+Shift makes a colour style or variable of what it picks; sidebar number and text fields keep their text vertically centered when focused, including typography spacing; with the pen out, Enter or a double-click ends the path and edits the vector with the Move tool instead of drawing on (#1430); the Actions palette offers only commands that run from it, and no second row reading like a menu item: Place image opens the file dialog (#1574); Preferences ▸ Scroll wheel zoom: a mouse wheel zooms the canvas about the pointer and Cmd/Ctrl+wheel scrolls (#1390); boolean operations refuse input past their caps, and a boolean group past them draws without its result (#1104); the selection and hover outlines of rounded rectangles and frames follow their corners (#1506); colour picker review fixes for text undo, fitted sidebars, moving controls and gradient variables; Corner smoothing: an original icon and the shared number-field drag gesture, preserving fractional baselines; guides snap to layers when dragged; Crop image: Object ▸ Crop image, the right-click menu and the image fill row enter crop mode (`image.crop`, #1464); the Design panel's sections on one grid — 16 / 8 margins, 88 + 8 + 88 + 8 + 24 columns, 24 pt rows, 4 pt between a row's buttons (#858); the toolbar on one 32 pt grid, without its Resources button (#1210); colour picker LCH and OKLCH models; an XML (Android Vector Drawable) export format; Context menus: the Menu key reaches egui 0.37 but is unbound (row done → partial); the Text on a path tool; board tool keys pinned; community fixes: the text box by dragging, the font picker keys, the pen path on leaving Design, a still canvas in vector edit mode, a scrolling pages list, colour emoji, readable new text in frames, system theme on first run; the Small caps sample in Type settings drawn from capitals; recent files as cards; vector edit mode: hovering, hatching, selecting and dragging filled regions; home screen: Templates tab, first-run templates and Getting started tips; number fields: scrub rates, arrow steps, arithmetic with brackets, relative edits of mixed values; outline mode's hidden layers and object bounds; Hide when publishing; cursors per tool and modifier; panel widths; dark pages for files made in the dark theme; drag threshold and double-clicks into text in groups; rotation origin on Alt+R and placing with Enter: no documented shortcut missing; keyboard shortcut parity suite and bindings; cursor chat and spotlight in live sessions; layers and assets panels behaviour suite and fixes; vector multi-edit and the vector edit tail; canvas navigation, guides and grids behaviour suite and fixes; shapes and vecLine truncated
 
 Fine canvas control is what Figma users feel first: handles, snapping, nudging, modifier keys,
 drag behaviour, numeric precision. This checklist covers the tools, gestures and panels. Status:
@@ -30,7 +30,7 @@ interaction feel not yet compared.
 | Colour names in hex fields | done | every hex field (fills, strokes, text ranges, effects, layout grids, colour variables, page and prototype backgrounds, the colour picker's Hex) takes a CSS colour name as well: `red` becomes `FF0000`; case, spaces and hyphens are ignored (`Light Blue`); names are opaque and keep the colour's opacity; hex wins where both could match. The picker's CSS field takes every CSS name too (`Color::from_hex_or_name`, `color::named`) |
 | Fields select their text on focus | done | Number and text values keep their vertical position when their editor gains focus (including typography spacing; `sidebar_field_text_stays_in_place_on_focus`). a click or Tab into a one-line field selects all of its text, so typing replaces the value: hex and colour fields, number fields, inline fields (a fill's hex, variable values, renames), names, search boxes and dialog fields; a drag from the press selects only what it covers; multi-line fields (descriptions, comments) keep the caret where clicked. The first click into an inline field (a fill's hex) now takes the keyboard; it took a second click. A rename (double-click, F2, File ▸ Rename, a page) selects the whole name before its field first draws, so a key typed in that same frame replaces the name; it was appended (`widgets::select_all_on_focus`, `select_all_tests`, `layers_rename_tests`) |
 | Colour picker models | done | Hex, RGB, HSL, HSB, LCH, OKLCH and CSS; LCH and OKLCH keep lightness and hue when a colour leaves sRGB (chroma comes down); the values typed stay while the colour is theirs (a hue typed on a grey, a chroma sRGB can't hold); CSS reads `lch()` and `oklch()` with any hue unit and `none` (`figcraft_color::{Lch, Oklch}`). Values are the stored channels read as sRGB |
-| Colour picker placement and dismissal | done | Opens 8 pt beside the sidebar at the opening control, lifted to fit the screen; outside presses (including the sidebar), Escape and X close it. Reopening resets a dragged position; eyedropper sampling keeps it open. |
+| Colour picker placement and dismissal | done | Opens 8 pt beside the sidebar at the opening control, lifted to fit the screen; outside presses (including the sidebar), Escape and X close it. Reopening resets a dragged position; eyedropper sampling keeps it open, and so does a drag of the open gradient's handles or stops on the canvas (#1852). |
 | Colour picker image well | partial | the Image tab shows a checkered placeholder and Upload from computer until there is a file (no dialog at once); an image paint shows its asset preview; a file dropped on the open picker replaces the image, keeping the fill mode, crop, position and adjustments (`image.replace`). Layers' fills and strokes only (text ranges, styles and selection colours keep Upload). The Fill and Stroke swatches take no drop: a dragged file's position isn't known, so a drop with none goes to the open picker |
 | Colour picker on a new fill or stroke | done | + opens the picker on the new paint when the selection shares one paint list; on a mixed selection + adds a paint to each layer and no picker opens (#404) |
 | Fill section on a text with coloured characters | done | a text's Fill section shows what its characters show: characters coloured differently while editing are mixed content ("Click + to replace mixed content", as a mixed selection; the developer documentation's `fills`: "Text nodes can have multiple sets of fills if some characters are colored differently than others"), and characters that all share fills the layer doesn't have show those. Any layer-level fill edit (a row, its picker, +, reordering, `fill.*`, `node.set`) reaches every character, starting from the list they showed; the characters' own fills go in the same undo step; the canvas gradient and crop handles show and edit the paint the row shows, the characters' own, also when their image is already in Crop mode (`text_mixed_fill_tests`, `canvas::handles::character_fill_tests`, engine `text_fill_tests`; #1856). A range selected while editing keeps its own Fill row |
@@ -114,7 +114,7 @@ interaction feel not yet compared.
 | Masks: what a mask hides doesn't take clicks; a mask group's box is the mask's | done | |
 | Layout grids (Ctrl+G) | done | columns, rows and grid; stretch, left, centre, right; Auto count; several per frame; styles; not shown or snapped on a rotated frame; a nested frame's grids snap but only top-level frames draw them |
 | Gamut warnings for Display P3 files | done | colour picker note; View ▸ Soft-proof sRGB stripes what sRGB can't show (the canvas itself is sRGB) |
-| Gradient and padding/gap handles on the canvas | done | |
+| Gradient and padding/gap handles on the canvas | done | the gradient's handles and stops show while its picker is open, and dragging one keeps the picker open (#1852) |
 | Hover outline, selection colours, handle sizes | done | measured from UI3 screenshots; the outline follows the layer's geometry, rounded corners (each radius and the smoothing) included, whatever the stroke alignment (#1506) |
 | Cursors per tool and modifier | done | the engine names a cursor for every tool, modifier and hover target (`tool.overlay.cursor`, tabled in `cursor_tests`) and the UI shows the system's or draws its own at the pointer (`cursors.rs`, `cursors_tests`; original glyphs from lines and the code-drawn icons). Arrow for Move and Scale; two-headed arrows on the handles that follow the handle and the box's rotation; outside a corner a curved rotate arrow turned to that corner, turning with the pointer while rotating; crosshair for the frame, section, slice, shape, pencil and Text tools; the I-beam over a text with the Text tool and over the text being edited; the pen as a cross with what a click does beside it (nothing: a new point; a ring: closes, connects to or goes on from a point; a plus: adds a point on a segment, also Alt in vector edit mode; a curve: bends, the Bend tool or Cmd/Ctrl); open and closed hand for the Hand tool, Space and the middle button; zoom in and out (Alt) while Z is held; eyedropper; comment pin; the copy cursor with Alt over a selected layer and while Alt-dragging; not-allowed while a drag resizes, rotates or moves a layer inside an instance (it is undone on release) and over a layers row that takes no drop. Ruler guides and gradient, crop and padding handles keep their own cursors (the tool's used to replace them). `ui.inspect` reports `cursor`. Left: no cursor for removing a point with the pen (the pen doesn't remove points); the drawn cursors follow the pointer a frame behind the system's; not compared with Figma's side by side |
 | Multiplayer cursors, cursor chat, spotlight | partial | in live sessions: named cursors, chat bubbles that fade, `/` to chat, spotlight from your avatar's menu with a banner; no audio or reactions |
@@ -180,6 +180,7 @@ in the table. `crates/ui-egui/src/shortcut_keys_tests.rs` drives the keys a look
 | Date | Change | Summary |
 |---|---|---|
 | 2026-11-02 | patch | Fill section: a text whose characters were coloured differently while editing shows mixed content, as a mixed selection does ("Text nodes can have multiple sets of fills if some characters are colored differently than others", the developer documentation's `fills`); characters that all share fills the layer doesn't have (all of them styled while editing) show those instead of the layer's older list; and a layer-level fill edit (a row, its picker, +, reordering, `fill.*`, `node.set`) reaches every character, their own fills going in the same undo step. The section used to show the layer's own fill, a single colour the canvas no longer showed (#1856). Tests: `text_mixed_fill_tests`, engine `text_fill_tests`. Numbers unchanged |
+| 2026-11-04 | patch | M1, #1852: a press on one of the open gradient's handles or stops on the canvas is the colour picker's own, not a press outside it (Figma keeps the picker and the handles up while a handle or stop is dragged; the stops are made to be dragged: "You can click and drag a stop to change its placement on the gradient", Use gradients as a fill or stroke). The canvas took the press and began the drag, then the picker, drawn later in the same frame, saw a press outside its card and closed, committing the drag's interaction at once; the handles vanished with it and the drag went on without an undo step of its own. Now the picker stays while a gradient handle or stop drags, and the drag is one undo step; a press elsewhere on the canvas still closes it. A handle drag whose button goes up off the canvas (over a panel or the picker) ends there too, instead of waiting, uncommitted, to move the handle to the next press on the canvas. Tests: `colorpicker_selection_tests::dragging_a_gradient_handle_on_the_canvas_keeps_the_picker_open`, `colorpicker_selection_tests::a_gradient_drag_released_off_the_canvas_ends_there`. |
 | 2026-11-02 | patch | M8, #1875: a click with the Bend tool on a sharp point between two segments gives it handles along the line between its neighbours, a third of the way to each ("Click on a point or path where you want to add a curve", Edit vector layers); a click on a curved point still makes it sharp, a drag still sets the handles by hand, an endpoint is left alone. Between a handle's end and a point both within reach of the pointer, the nearer one on the page is hit (the handle on a tie), so a short path's point (its handles a few pixels long) can be clicked again. Before, only a drag curved a point, and a short one left two tiny handles in its direction. Tests: `vectoredit::tests::short_handles_leave_their_point_clickable`, `vectoredit::tests::a_bend_click_curves_a_sharp_point_between_its_neighbours`, `bend_tool_smooths_and_sharpens_points`. Numbers unchanged. |
 | 2026-11-02 | minor | M4, #1827: wrap style on a text layer (`WrapStyle`: Auto, Balance, Pretty): Balance re-breaks each paragraph at the narrowest width that keeps its line count (bisection over the greedy breaker, as browsers balance), Pretty narrows one of the last four lines just enough so the last line isn't one word; `text.wrapStyle`, `node.set wrapStyle` (`textWrap` too), inspect `wrapStyle`, Dev Mode CSS `text-wrap` (Tailwind `text-balance` / `text-pretty`), the Type settings control under Vertical trim. Per-paragraph settings, text-style support and the `.fig` import/export mapping stay open. Test: `text_behaviour_tests::balance_and_pretty_wrap_styles_break_lines_as_documented`. |
 | 2026-11-02 | patch | M4: Backspace or Delete at the start of a list item takes its marker and keeps its level ("Use Backspace or Delete at the beginning of a list item to delete the counter, but keep the same level of indentation", Create bulleted and numbered lists): a plain paragraph may now carry a list level, and the text layout starts it where that level's item text starts (the gutters stay even when no list is left). Backspace used to drop the level too, and Delete at an item's start deleted the next character. Tab on such a paragraph types a tab, as outside a list. Tests: `text_tail_tests::list_keys_at_list_items`, text crate `behaviour_tests::a_plain_paragraph_at_a_list_level_starts_where_the_items_text_does` |

packaging/web/README.md

@@ -107,6 +107,104 @@ Local test: `python3 -m http.server 8767` inside the folder, then open http://lo
   (`allow-popups` lets Help links open in a new tab).
 - Don't send `X-Frame-Options: DENY` or a `frame-ancestors` CSP that excludes the embedding page.
 
+## Host mode (`?host=parent`, or the page's own document)
+
+A page can embed FigCraft so that it hands files over instead of downloading them and reports
+unsaved changes. Two opt-in transports carry the same messages:
+
+- **`?host=parent`** on the iframe's URL (`https://example.com/figcraft/?host=parent`): a
+  **same-origin** framing page talks to the app over `postMessage`. Opened outside an iframe, the
+  URL gives the normal app with downloads; with a parent on another origin there is no host mode
+  either (messages to another origin are dropped silently, so saves would be lost while the
+  document looked saved).
+- **`data-host="page"`** (the exact value `page`) on the canvas: a page that loads the module into
+  its own document gets the same behaviour over DOM `CustomEvent`s on the canvas, with no iframe
+  (see below).
+
+| Message | Direction | Fields |
+|---|---|---|
+| `figcraft:ready` | app → page | `version`, `appVersion`: the app is running and listening; send a file now |
+| `figcraft:open` | page → app | `name`, `bytes` (an `ArrayBuffer` or `Uint8Array`): open like File › Open (a payload over the browser open limit of 512 MB is refused; anything malformed is ignored) |
+| `figcraft:save` | app → page | `name`, `saveAs`, `bytes` (a transferred `ArrayBuffer`): every file the app would otherwise download. The page stores it and reports failures itself. `saveAs` says whether the file becomes the document's file: `false` after Save of the file the page sent, under its own name; `true` for a document file (`.figcraft`, `.json`) under a name the page didn't send — Save As, or a Save of a document the page never sent — after which the next Save carries that name with `false`; `false` for copies and exports that don't become the document (rendered images, SVG, PDF, `.fig` copies, the variables exports) |
+| `figcraft:dirty` | app → page | `dirty`: unsaved changes appeared or went away |
+| `figcraft:failed` | app → page | `error`: the app couldn't start (no WebGPU or WebGL2, for example) |
+
+Files reach the page through the app's download service, the path this web build saves by: Save As
+(and a Save of a document with no file yet), the `.fig` copy, the export panel and its dialog,
+Export frames as PDF, plugin output and the variables export (Variables panel ▸ Export…). In host
+mode each arrives as `figcraft:save` instead of a download.
+
+In host mode the app starts with no document (the home screen), so the page sends the file to edit
+and guards leaving the page while changes are unsaved. `&author=` on the URL names the user for
+comments and board notes.
+
+### Same-document host mode
+
+The host application loads the wasm-bindgen module itself and gives FigCraft one of its own
+canvases, so there is no iframe and no `?host=parent`. It opts in with `data-host="page"` on that
+canvas — the exact value `page` — and the canvas keeps the id the app looks up
+(`id="figcraft_canvas"`):
+
+```html
+<canvas id="figcraft_canvas" data-host="page" style="width: 100%; height: 720px; display: block;"></canvas>
+```
+
+The page and the app then talk with DOM `CustomEvent`s on the canvas instead of `postMessage`. The
+app dispatches the same messages it would post to a parent — `figcraft:ready`, `figcraft:save`,
+`figcraft:dirty`, `figcraft:failed` — with the message fields (without the type) as the event's
+`detail`, and it opens a document when the page dispatches a `figcraft:open` event with
+`detail: { name, bytes }`. Events do not bubble, so listen on the canvas itself (two editors on
+one page can't hear each other).
+
+Add the listeners before `init`: the app announces itself with `figcraft:ready` while `init` is
+still running, and a file sent in reply would otherwise be missed.
+
+```js
+import init from "./figcraft-web-<hash>.js"; // the wasm-bindgen glue shipped with the app
+
+const canvas = document.getElementById("figcraft_canvas");
+
+canvas.addEventListener("figcraft:ready", async () => {
+  // The app is listening; hand it a document now, if you have one.
+  const bytes = await documentBytes(); // an ArrayBuffer or Uint8Array
+  canvas.dispatchEvent(new CustomEvent("figcraft:open", {
+    detail: { name: "Poster.figcraft", bytes },
+  }));
+});
+
+// Every file FigCraft would otherwise download arrives here.
+canvas.addEventListener("figcraft:save", (event) => {
+  const { name, saveAs, bytes } = event.detail; // bytes is an ArrayBuffer
+  // Store the file under `name`; `saveAs` says whether it becomes the document's file.
+  // Report your own errors.
+  storeFile(name, bytes, saveAs);
+});
+canvas.addEventListener("figcraft:dirty", (event) => {
+  unsaved = event.detail.dirty; // warn before leaving, as you like
+});
+canvas.addEventListener("figcraft:failed", (event) => {
+  showError(event.detail.error); // the app couldn't start
+});
+
+await init({ module_or_path: "./figcraft-web-<hash>_bg.wasm" });
+```
+
+- Saves are not downloads in this mode: the `bytes` in `figcraft:save` hold the file, and the host
+  decides where it goes.
+- `?author=` on the page's URL still names the user for comments and board notes.
+- An unframed page that uses `?host=parent` keeps the normal app with downloads.
+  `data-host="page"` turns this mode on only when `?host=parent` is absent: if `?host=parent` is
+  present it takes precedence, so a same-origin framed page uses the parent bridge, while an
+  unframed or cross-origin page gets no bridge and keeps normal downloads.
+
+The messages and both transports are the shared contract of [`craft-web-host`](https://github.com/storytold/craft-libs/tree/main/crates/web-host) (storytold/craft-libs#420), the same for every Craft app: its README lists every message, including `saved`, with the compatibility notes. In `figcraft:ready`, `version` is the contract's (`"1"`) and `appVersion` is this app's release. FigCraft reads bytes, so a host sends `bytes`, not a `File`.
+
+### Trust and limits
+
+- **Who is trusted.** In page host mode the page and FigCraft share one document, so any script on the page can drive the app: open files in it and receive what it saves. Use this mode only for a page you control. The iframe mode (`?host=parent`) answers only the parent window, on the page's own origin.
+- **Files from the host are untrusted input.** An opened file goes through the same reading as one picked with File ▸ Open or dropped on the window, with the same format limits; before it is copied into the app's memory, its size is checked against the host open limit (512 MB) and a larger file is refused, and a name is cut to 255 characters.
+- **The event and message names are the interface.** `figcraft:ready`, `figcraft:open`, `figcraft:save`, `figcraft:dirty` and `figcraft:failed`, and the fields they carry (the same as the `?host=parent` messages), stay stable; changing one is a breaking change.
+
 ## Renderer selection and fallback flags
 
 FigCraft renders with wgpu. It uses **WebGPU** when the browser has it and falls back to