Fix #585 : a two-finger tap undoes, a three-finger tap redoes

Preferences › Devices › Enable Touch Gestures (on by default) was stored but nothing read it: no touch gesture was implemented. - `touch::Taps` follows the fingers egui reports (winit reads them from the system: WM_POINTER on Windows): fingers down together and lifted within half a second, none moved more than 16 points, is a tap. Two fingers undo, three redo, with the preference on. - egui makes the first finger the pointer too, so it has pressed on the canvas by the time a second lands: that press is dropped then (its tool interaction rolled back), and the rest of the gesture presses nothing. The tap so undoes what came before it, not the first finger's mark. - A pen is one contact, so pen strokes and taps are unaffected; pinch zoom is unchanged. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Merge pull request: land #616 (fix #597 )
2026-10-09 05:39:47 +07:00 · 2026-10-09 05:31:24 +07:00 · 2026-10-09 05:26:43 +07:00 · 2026-10-09 05:25:17 +07:00 · 2026-10-09 05:22:09 +07:00
9 changed files with 267 additions and 7 deletions
@@ -4,7 +4,7 @@ VectorCraft is a clean-room, open-source, pure-Rust reimplementation of the Adob

 This file tracks **how far we are and what's left**. Time estimates are wall-clock hours of continuous Claude Opus 5.5 agent work (including builds and the CI gate), given both for **one agent** and for **4–6 parallel agents** on disjoint crates. They are counted from the remaining work (see [Parity estimate](#parity-estimate)), calibrated against measured throughput, and updated as work lands.

-_Last updated: 2026-10-09 (after placed documents (File › Place of a `.vectorcraft` file, linked), M4.14–M4.98, M8.1–M8.20, M14.4–M14.7, the MCP prompts, resource templates, completions and logging, the 2026-10-07 issue fixes, the Layers panel rework and the 2026-10-08 community contributions: Pen and shape-tool modifiers, path editing, Layers, Artboards, Swatches/Brushes and dialogs, Japanese composition and PDF text, Hebrew/Arabic type, interface languages (Spanish among them), the font menu, saved selections, MCP and EPS, the missing-font export warning (#319), open paths in the Shape Builder (#374), PDF/`.ai` import keeping strokes live and hidden and nested layers (#372), per-corner Live Corners (#381), SVG type opening at the size it draws at (#396), the Wayland clipboard with copied-file paste (#398), ruler guides that can be selected, moved and deleted (#414), two batches of Preferences options that were stored but unused (#394), skeleton reads with `document.find` for large documents over MCP (#416) and anchors dragged with Direct Selection snapping to points, segments and smart guides, clipped SVG layers opening as clipping layers (#420), PDF/`.ai` layers read on pages of tens of millions of operators (#419), Document Color Mode putting RGB greys on the black plate on request and converting pattern tiles (#421) and movable dialogs with Offset Path's Joins dropdown (#423) and numeric fields scrubbed by dragging their label (#400), stroke weight presets in the stroke unit (#426), the Appearance panel's Opacity popup (#430), type on a path brackets, flip and Type on a Path Options that keep the type in place (#429), Layers rows dragged with a ghost and dropped on the trash or New Layer (#435), tool flyouts opening on a right or corner press (#436), tool flyouts torn off into floating toolbars (#437), the Shape Builder's erase mode deleting edges too (#439), installed fonts registered outside the font folders and fonts installed while the app runs listed in the font menus (#443), alike circular corners on rectangles that aren't square (#442), tool cursors as OS cursors so the pointer no longer trails over the canvas (#444), artboards copied and pasted with their art (#446), guides dragged out of the rulers snapping to the art's side midpoints and the artboards, artboard guides (#451), the toolbar's double arrow and Window › Toolbars › Double Column switching between one and two columns in any window height (#455), the Smart Guides display options and Snapping Tolerance (#394), Font Size and Leading combo boxes with preset lists in the Character and Properties panels and the Control bar (#458), screenshots pasted from the clipboard on macOS, Windows and the web (#457), the Properties panel's Fill and Stroke matching the Control bar's, Illustrator's Window menu panel keys (Shift+F7 for Align…) and Alt-wheel zoom whatever the wheel preference (Discord feedback), the point/area type widget (Discord feedback), groups in legacy Illustrator .ai files (Discord feedback), a rotating desktop log file (#465), image controls in the Control bar and Properties panel: Image Trace with its presets, Mask, Crop Image, Embed/Unembed, and an Image Trace object's preset, Expand and Release (Discord feedback), the Pen working as the Anchor Point tool with Alt held over a selected path's handles and anchors, and anchor buttons that convert, connect and cut paths at the selected anchors (Discord feedback), Japanese hanging punctuation (burasagari, #463), Escape leaving Presentation Mode with no screen mode saved across restarts, documents dropped on the desktop app opening as tabs of their own and a note that an `.ai` file's art off its artboards isn't in the part read (#472), Add/Delete Anchor Point tool icons drawn from the Pen tool's (#479), EPS import running more of PostScript Level 3 (patterns, Type 3 fonts, mesh shadings, masked images, VM and resource probes), and a preview that stands in saying why (Discord feedback, #466, #469, #474), chords with modifiers recorded in Edit › Keyboard Shortcuts (#487), Type Object Selection by Path Only (#394), Anti-aliased Artwork (#394), Show Pixel Grid (#394), pen and touch taps pressed and lifted within one frame clicking where they tapped and the Linux/Wayland pen-tablet workaround (#491), bounding-box resizes landing on the other objects' anchors and centres with labels, and the Rotate, Scale, Shear and Reflect tools snapping their drags (#482), Shift-drag marquees that toggle the objects or anchors they reach and a Lasso whose Alt subtraction keeps the rest of the selection (#483), the mouse wheel stepping the focused numeric field, the dialogs' and preferences' drag values made such fields (#485), Show The Home Screen When No Documents Are Open (#394), Numbers Without Units Are Points (#394), Auto-Collapse Iconic Panels (#394), the Contextual Task Bar moved by its handle and its More Options menu pinning and resetting its position, a designed macOS DMG windoLine truncated
+_Last updated: 2026-10-09 (after placed documents (File › Place of a `.vectorcraft` file, linked), M4.14–M4.98, M8.1–M8.20, M14.4–M14.7, the MCP prompts, resource templates, completions and logging, the 2026-10-07 issue fixes, the Layers panel rework and the 2026-10-08 community contributions: Pen and shape-tool modifiers, path editing, Layers, Artboards, Swatches/Brushes and dialogs, Japanese composition and PDF text, Hebrew/Arabic type, interface languages (Spanish among them), the font menu, saved selections, MCP and EPS, the missing-font export warning (#319), open paths in the Shape Builder (#374), PDF/`.ai` import keeping strokes live and hidden and nested layers (#372), per-corner Live Corners (#381), SVG type opening at the size it draws at (#396), the Wayland clipboard with copied-file paste (#398), ruler guides that can be selected, moved and deleted (#414), two batches of Preferences options that were stored but unused (#394), skeleton reads with `document.find` for large documents over MCP (#416) and anchors dragged with Direct Selection snapping to points, segments and smart guides, clipped SVG layers opening as clipping layers (#420), PDF/`.ai` layers read on pages of tens of millions of operators (#419), Document Color Mode putting RGB greys on the black plate on request and converting pattern tiles (#421) and movable dialogs with Offset Path's Joins dropdown (#423) and numeric fields scrubbed by dragging their label (#400), stroke weight presets in the stroke unit (#426), the Appearance panel's Opacity popup (#430), type on a path brackets, flip and Type on a Path Options that keep the type in place (#429), Layers rows dragged with a ghost and dropped on the trash or New Layer (#435), tool flyouts opening on a right or corner press (#436), tool flyouts torn off into floating toolbars (#437), the Shape Builder's erase mode deleting edges too (#439), installed fonts registered outside the font folders and fonts installed while the app runs listed in the font menus (#443), alike circular corners on rectangles that aren't square (#442), tool cursors as OS cursors so the pointer no longer trails over the canvas (#444), artboards copied and pasted with their art (#446), guides dragged out of the rulers snapping to the art's side midpoints and the artboards, artboard guides (#451), the toolbar's double arrow and Window › Toolbars › Double Column switching between one and two columns in any window height (#455), the Smart Guides display options and Snapping Tolerance (#394), Font Size and Leading combo boxes with preset lists in the Character and Properties panels and the Control bar (#458), screenshots pasted from the clipboard on macOS, Windows and the web (#457), the Properties panel's Fill and Stroke matching the Control bar's, Illustrator's Window menu panel keys (Shift+F7 for Align…) and Alt-wheel zoom whatever the wheel preference (Discord feedback), the point/area type widget (Discord feedback), groups in legacy Illustrator .ai files (Discord feedback), a rotating desktop log file (#465), image controls in the Control bar and Properties panel: Image Trace with its presets, Mask, Crop Image, Embed/Unembed, and an Image Trace object's preset, Expand and Release (Discord feedback), the Pen working as the Anchor Point tool with Alt held over a selected path's handles and anchors, and anchor buttons that convert, connect and cut paths at the selected anchors (Discord feedback), Japanese hanging punctuation (burasagari, #463), Escape leaving Presentation Mode with no screen mode saved across restarts, documents dropped on the desktop app opening as tabs of their own and a note that an `.ai` file's art off its artboards isn't in the part read (#472), Add/Delete Anchor Point tool icons drawn from the Pen tool's (#479), EPS import running more of PostScript Level 3 (patterns, Type 3 fonts, mesh shadings, masked images, VM and resource probes), and a preview that stands in saying why (Discord feedback, #466, #469, #474), chords with modifiers recorded in Edit › Keyboard Shortcuts (#487), Type Object Selection by Path Only (#394), Anti-aliased Artwork (#394), Show Pixel Grid (#394), pen and touch taps pressed and lifted within one frame clicking where they tapped and the Linux/Wayland pen-tablet workaround (#491), bounding-box resizes landing on the other objects' anchors and centres with labels, and the Rotate, Scale, Shear and Reflect tools snapping their drags (#482), Shift-drag marquees that toggle the objects or anchors they reach and a Lasso whose Alt subtraction keeps the rest of the selection (#483), the mouse wheel stepping the focused numeric field, the dialogs' and preferences' drag values made such fields (#485), Show The Home Screen When No Documents Are Open (#394), Numbers Without Units Are Points (#394), Auto-Collapse Iconic Panels (#394), the Contextual Task Bar moved by its handle and its More Options menu pinning and resetting its position, a designed macOS DMG windoLine truncated

 ## Where we are

@@ -6,7 +6,7 @@ use std::rc::Rc;
 use std::sync::{Arc, Mutex};

 use vectorcraft_engine::Session;
-use vectorcraft_engine::cmd::clipboard::{FILE_HEAD, Flavour, PASTE_ORDER, file_flavour};
+use vectorcraft_engine::cmd::clipboard::{FILE_HEAD, Flavour, PASTE_ORDER, file_flavour, is_address};
 use vectorcraft_engine::cmd::fileio;
 use vectorcraft_engine::cmd::recovery::{self, Hold, RecoveryStore};
 use vectorcraft_ui_egui::graphics::GraphicsLoss;
@@ -200,7 +200,8 @@ fn track_paste(pasted: &Rc<RefCell<Pasted>>) {
    let on_paste = wasm_bindgen::closure::Closure::<dyn FnMut(web_sys::ClipboardEvent)>::new(move |e: web_sys::ClipboardEvent| {
        let Some(data) = e.clipboard_data() else { return };
        let Some(files) = data.files().filter(|f| f.length() > 0) else { return };
-        if data.get_data("text").is_ok_and(|t| !t.is_empty()) {
+        // Text is egui's, but for the address a browser's Copy Image puts next to the picture.
+        if data.get_data("text").is_ok_and(|t| !t.is_empty() && !is_address(&t)) {
            return;
        }
        e.prevent_default();
@@ -21,7 +21,7 @@ use vectorcraft_color::Swatch;
 use vectorcraft_doc::{Document, GraphicStyle, ImageBlob, Node, NodeId, PatternDef, Symbol, TextStyleDef};
 use vectorcraft_geom::Rect;

-pub use flavours::{BITMAP, EMF, FILE_HEAD, Flavour, PASTE_ORDER, PDF, PNG, SVG, TEXT, file_flavour};
+pub use flavours::{BITMAP, EMF, FILE_HEAD, Flavour, PASTE_ORDER, PDF, PNG, SVG, TEXT, file_flavour, is_address};
 pub(crate) use resources::SwatchChoices;

 use super::*;
@@ -220,6 +220,25 @@ mod tests {
        s
    }

+    /// The address a browser's Copy Image puts next to the picture (#597), and text that isn't one.
+    #[test]
+    fn an_address_alone_is_told_from_other_text() {
+        for a in [
+            "https://example.com/cat.png",
+            " http://x.org/a?b=1
+",
+            "HTTPS://EXAMPLE.COM",
+            "file:///C:/art/cat.png",
+            "data:image/png;base64,iVBOR",
+            "blob:https://x.org/1",
+        ] {
+            assert!(is_address(a), "{a}");
+        }
+        for t in ["Pasted words", "see https://example.com", "https://a.org https://b.org", "https://", "example.com/cat.png", ""] {
+            assert!(!is_address(t), "{t}");
+        }
+    }
+
    #[test]
    fn copy_exports_svg_that_round_trips_through_paste() {
        let mut s = session();
@@ -30,6 +30,15 @@ pub const EMF: &str = "image/emf";
 /// What Paste reads from other apps, best first: vector art before text, text before bitmaps
 /// (word processors offer a picture of copied text too).
 pub const PASTE_ORDER: [&str; 5] = [SVG, PDF, EMF, TEXT, BITMAP];
+/// Is `text` only an address (a web page's, an image's, a file's)? A browser's Copy Image puts the
+/// image's address as text next to the picture: then the picture is what Paste takes (#597). An
+/// address alone pastes as text, and nothing is fetched.
+pub fn is_address(text: &str) -> bool {
+    const SCHEMES: [&str; 6] = ["http://", "https://", "file://", "ftp://", "data:", "blob:"];
+    let t = text.trim();
+    !t.chars().any(char::is_whitespace) && SCHEMES.iter().any(|s| t.get(..s.len()).is_some_and(|h| h.eq_ignore_ascii_case(s)) && t.len() > s.len())
+}
+
 /// How much of a copied file [`file_flavour`] needs to tell what it is.
 pub const FILE_HEAD: usize = 4096;

@@ -79,6 +79,8 @@ enum Drag {
    /// A Selection tool move dragged off the canvas: the panels get the art
    /// ([`widgets::PanelDrag::Art`]).
    Art,
+    /// Fingers making a touch gesture ([`crate::touch`]): the first one's press does nothing.
+    Gesture,
 }

 fn drag_id() -> egui::Id {
@@ -474,6 +476,7 @@ fn handle_input(app: &mut VectorcraftApp, ui: &Ui, resp: &egui::Response, rect:
    let at = hover.or_else(|| pointer.interact_pos().filter(|p| rect.contains(*p)));
    app.hover_doc = hover.map(|p| xf.to_doc(p));
    let view = app.view_info();
+    touch_gestures(app, ui, rect, view);
    let drag: Option<Drag> = ui.data(|d| d.get_temp(drag_id()));
    // A modifier pressed or released over the canvas re-hovers the tool, so what it changes shows
    // without moving the mouse (Alt switches the Shape Builder to erase mode).
@@ -565,7 +568,7 @@ fn handle_input(app: &mut VectorcraftApp, ui: &Ui, resp: &egui::Response, rect:
                        vm.rotation = vectorcraft_geom::normalize_deg(deg);
                    }
                }
-                Drag::ZoomBox { .. } | Drag::Art => {}
+                Drag::ZoomBox { .. } | Drag::Art | Drag::Gesture => {}
                Drag::Tool if drag_art_out(app, ui, resp, p, view) => {
                    ui.data_mut(|dd| dd.insert_temp(drag_id(), Drag::Art));
                }
@@ -609,7 +612,7 @@ fn handle_input(app: &mut VectorcraftApp, ui: &Ui, resp: &egui::Response, rect:
                    let ev = PointerEvent { kind: PointerKind::Up, pos: xf.to_doc(p), mods: mods(m, space), pressure: pen_pressure(ui, false) };
                    dispatch(app, &ev, view);
                }
-                Drag::Art => {}
+                Drag::Art | Drag::Gesture => {}
                Drag::Pan { .. } | Drag::RotateView { .. } => {}
            }
        }
@@ -688,6 +691,50 @@ fn wheel(i: &egui::InputState, wheel_zooms: bool, line: f32, page: f32, alt_turn
    (zoom, scroll)
 }

+/// Enable Touch Gestures: this frame's finger contacts on the canvas ([`crate::touch`]). A second
+/// finger drops the press the first one began (its tool interaction rolled back; the rest of the
+/// gesture presses nothing), and a tap of two fingers undoes, one of three redoes.
+fn touch_gestures(app: &mut VectorcraftApp, ui: &Ui, rect: egui::Rect, view: vectorcraft_engine::ViewInfo) {
+    if !app.session.prefs.touch_gestures {
+        return;
+    }
+    let (touches, now): (Vec<_>, f64) = ui.input(|i| {
+        let t = i.events.iter().filter_map(|e| match e {
+            egui::Event::Touch { id, phase, pos, .. } => Some((*id, *phase, *pos)),
+            _ => None,
+        });
+        (t.collect(), i.time)
+    });
+    if touches.is_empty() {
+        return;
+    }
+    let key = egui::Id::new("canvas-touch");
+    let mut taps: crate::touch::Taps = ui.data(|d| d.get_temp(key)).unwrap_or_default();
+    let mut tap = None;
+    for (id, phase, pos) in touches {
+        // A gesture begins on the canvas.
+        if phase == egui::TouchPhase::Start && !taps.is_down() && !rect.contains(pos) {
+            continue;
+        }
+        match taps.feed(id, phase, pos, now) {
+            Some(crate::touch::Touch::Fingers) => {
+                if ui.data(|d| d.get_temp::<Drag>(drag_id())) == Some(Drag::Tool) {
+                    // Nothing it began is kept; the tool's mouse-up returns it to rest.
+                    let _ = app.session.cancel_interaction();
+                    dispatch(app, &PointerEvent { kind: PointerKind::Up, pos: Point::ZERO, mods: Mods::default(), pressure: 1.0 }, view);
+                }
+                ui.data_mut(|d| d.insert_temp(drag_id(), Drag::Gesture));
+            }
+            Some(crate::touch::Touch::Tap(n)) => tap = crate::touch::tap_command(n),
+            None => {}
+        }
+    }
+    ui.data_mut(|d| d.insert_temp(key, taps));
+    if let Some(cmd) = tap {
+        crate::menus::invoke(app, cmd, serde_json::json!({}));
+    }
+}
+
 /// A Selection tool move dragged off the canvas (to `p`, over a panel) turns into a panel drag of
 /// the selected art ([`widgets::PanelDrag::Art`]): the move is dropped, so the art stays where it
 /// was, and the panel it is released on takes it (the Graphic Styles panel makes a style of it).
@@ -1865,6 +1912,40 @@ mod tests {
        out.textures_delta.clear();
    }

+    /// Enable Touch Gestures (#585): a two-finger tap undoes and a three-finger one redoes, and the
+    /// first finger's press (the pointer egui makes of it) draws nothing. Off, a tap does nothing.
+    #[test]
+    fn two_finger_tap_undoes_and_three_finger_tap_redoes() {
+        let mut app = VectorcraftApp::new(Session::new(), Default::default());
+        app.session.execute("file.new", &json!({"width": 400, "height": 300})).unwrap();
+        app.session.execute("shape.rectangle", &json!({"x": 50, "y": 50, "width": 40, "height": 40})).unwrap();
+        app.select_tool("rectangle");
+        let ctx = egui::Context::default();
+        frame(&mut app, &ctx, vec![]);
+        let count = |app: &VectorcraftApp| app.session.active().unwrap().doc.layers[0].children().unwrap().len();
+        let c = app.canvas_rect.unwrap().center();
+        let touch = |n: u64, phase, pos| egui::Event::Touch { device_id: egui::TouchDeviceId(1), id: egui::TouchId(n), phase, pos, force: None };
+        let button = |pos, pressed| egui::Event::PointerButton { pos, button: egui::PointerButton::Primary, pressed, modifiers: Default::default() };
+        // `fingers` fingers tap at the centre, the first also pressing as the pointer and moving a
+        // little (as a rectangle drag would begin).
+        let tap = |app: &mut VectorcraftApp, fingers: u64| {
+            let at = |n: u64| c + vec2(n as f32 * 50.0, 0.0);
+            frame(app, &ctx, vec![touch(0, egui::TouchPhase::Start, at(0)), egui::Event::PointerMoved(at(0)), button(at(0), true)]);
+            frame(app, &ctx, vec![touch(0, egui::TouchPhase::Move, at(0) + vec2(6.0, 6.0)), egui::Event::PointerMoved(at(0) + vec2(6.0, 6.0))]);
+            frame(app, &ctx, (1..fingers).map(|n| touch(n, egui::TouchPhase::Start, at(n))).collect());
+            frame(app, &ctx, vec![touch(0, egui::TouchPhase::End, at(0)), button(at(0) + vec2(6.0, 6.0), false), egui::Event::PointerGone]);
+            frame(app, &ctx, (1..fingers).map(|n| touch(n, egui::TouchPhase::End, at(n))).collect());
+            frame(app, &ctx, vec![]);
+        };
+        tap(&mut app, 2);
+        assert_eq!(count(&app), 0, "the rectangle undone, none drawn");
+        tap(&mut app, 3);
+        assert_eq!(count(&app), 1, "redone");
+        app.session.prefs.touch_gestures = false;
+        tap(&mut app, 2);
+        assert_eq!(count(&app), 2, "off: the first finger draws as the pointer, and nothing is undone");
+    }
+
    /// The Artboard tool's label holds the artboard's name (never translated); the tools' own
    /// labels are interface text.
    #[test]
@@ -50,6 +50,7 @@ pub mod sysclip;
 pub mod theme;
 pub mod titlebar;
 pub mod toolbar;
+mod touch;
 mod ui_fonts;
 pub mod unsaved;
 pub mod widgets;
@@ -8,7 +8,7 @@
 //! reads from a paste itself ([`VectorcraftApp::paste_from_host`]).

 use serde_json::{Value, json};
-use vectorcraft_engine::cmd::clipboard::{EMF, Flavour, PASTE_ORDER, PDF, SVG, TEXT, looks_like_svg};
+use vectorcraft_engine::cmd::clipboard::{BITMAP, EMF, Flavour, PASTE_ORDER, PDF, SVG, TEXT, is_address, looks_like_svg};

 use crate::VectorcraftApp;

@@ -90,6 +90,8 @@ impl VectorcraftApp {
                    return Ok(());
                }
                let Some(f) = cb.read(&PASTE_ORDER) else { return Ok(()) };
+                // Text that is only an address goes with a browser's copied picture: the picture.
+                let f = if f.mime == TEXT && is_address(&String::from_utf8_lossy(&f.data)) { cb.read(&[BITMAP]).unwrap_or(f) } else { f };
                import_command(&f, center)
            }
            // Text only: SVG markup is art, other text is left alone.
@@ -167,6 +167,22 @@ fn text_from_another_app_pastes_as_point_text_and_svg_text_as_art() {
    assert_eq!(count(&app), before);
 }

+/// A browser's Copy Image: the picture with its address as text (and HTML, which Paste doesn't
+/// read). The picture is pasted; an address alone pastes as text, nothing is fetched (#597).
+#[test]
+fn an_image_copied_in_a_browser_pastes_as_the_picture_not_its_address() {
+    let (mut app, board) = app();
+    let url = b"https://example.com/images/cat.png".to_vec();
+    copy_elsewhere(&board, vec![(TEXT, url.clone()), ("text/html", b"<img src=\"https://example.com/images/cat.png\">".to_vec()), (PNG, blue_png())]);
+    run(&mut app, "edit.paste", json!({}));
+    let NodeKind::Image(im) = &pasted(&app)[0].kind else { panic!("not an image: {:?}", pasted(&app)[0].kind) };
+    assert!(im.link.is_none() && (im.width, im.height) == (4, 2));
+    copy_elsewhere(&board, vec![(TEXT, url)]);
+    run(&mut app, "edit.paste", json!({}));
+    let NodeKind::Text(t) = &pasted(&app)[0].kind else { panic!("not type") };
+    assert_eq!(t.plain_text(), "https://example.com/images/cat.png");
+}
+
 #[test]
 fn a_pdf_from_another_app_pastes_as_vectors_ahead_of_its_bitmap() {
    let (mut app, board) = app();
@@ -0,0 +1,131 @@
+//! Touch gestures on the canvas (Preferences › Devices › Enable Touch Gestures, #585): a tap with
+//! two fingers undoes, one with three redoes.
+//!
+//! egui hands every finger's contact over as [`egui::Event::Touch`] (winit reads them from the
+//! system: `WM_POINTER` on Windows), and makes the first finger the mouse pointer too. So the first
+//! finger has pressed on the canvas by the time a second lands: that press is dropped then
+//! ([`Taps::feed`] says [`Touch::Fingers`]), and the tap undoes what came before it.
+
+use egui::{Pos2, TouchId, TouchPhase};
+
+/// How long the fingers of a tap may stay down, in seconds.
+const TAP_TIME: f64 = 0.5;
+/// How far (points) a finger of a tap may move: further, it is a pinch or a pan.
+const TAP_SLOP: f32 = 16.0;
+
+/// What a touch event made of the gesture.
+#[derive(Clone, Copy, Debug, PartialEq, Eq)]
+pub(crate) enum Touch {
+    /// A second finger landed: the gesture isn't the first finger's press.
+    Fingers,
+    /// All fingers lifted from a tap of this many fingers (two or more).
+    Tap(usize),
+}
+
+/// The fingers down and how the gesture they make has gone so far.
+#[derive(Clone, Debug, Default)]
+pub(crate) struct Taps {
+    /// Each finger down and where it landed.
+    down: Vec<(TouchId, Pos2)>,
+    /// The most fingers down at once in this gesture.
+    most: usize,
+    /// When its first finger landed.
+    start: f64,
+    /// A finger moved too far or stayed too long: not a tap.
+    spoilt: bool,
+}
+
+impl Taps {
+    /// Follow a finger's `phase` at `pos` (touch `id`) at time `now` (seconds).
+    pub(crate) fn feed(&mut self, id: TouchId, phase: TouchPhase, pos: Pos2, now: f64) -> Option<Touch> {
+        match phase {
+            TouchPhase::Start => {
+                if self.down.is_empty() {
+                    *self = Self { start: now, ..Self::default() };
+                }
+                if !self.down.iter().any(|(d, _)| *d == id) {
+                    self.down.push((id, pos));
+                }
+                let before = self.most;
+                self.most = self.most.max(self.down.len());
+                (before < 2 && self.most >= 2).then_some(Touch::Fingers)
+            }
+            TouchPhase::Move => {
+                if self.down.iter().any(|(d, at)| *d == id && at.distance(pos) > TAP_SLOP) {
+                    self.spoilt = true;
+                }
+                None
+            }
+            TouchPhase::End | TouchPhase::Cancel => {
+                let known = self.down.len();
+                self.down.retain(|(d, _)| *d != id);
+                if self.down.len() == known {
+                    return None;
+                }
+                self.spoilt |= phase == TouchPhase::Cancel || now - self.start > TAP_TIME;
+                (self.down.is_empty() && !self.spoilt && self.most >= 2).then_some(Touch::Tap(self.most))
+            }
+        }
+    }
+
+    /// A finger is down.
+    pub(crate) fn is_down(&self) -> bool {
+        !self.down.is_empty()
+    }
+}
+
+/// The command a tap of `fingers` runs: two undo, three redo.
+pub(crate) fn tap_command(fingers: usize) -> Option<&'static str> {
+    match fingers {
+        2 => Some("edit.undo"),
+        3 => Some("edit.redo"),
+        _ => None,
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn id(n: u64) -> TouchId {
+        TouchId(n)
+    }
+
+    #[test]
+    fn two_and_three_finger_taps() {
+        let mut t = Taps::default();
+        let p = Pos2::new(100.0, 100.0);
+        assert_eq!(t.feed(id(1), TouchPhase::Start, p, 0.0), None);
+        assert_eq!(t.feed(id(2), TouchPhase::Start, p + egui::vec2(60.0, 0.0), 0.05), Some(Touch::Fingers));
+        assert!(t.is_down());
+        assert_eq!(t.feed(id(1), TouchPhase::Move, p + egui::vec2(3.0, 2.0), 0.1), None);
+        assert_eq!(t.feed(id(1), TouchPhase::End, p, 0.15), None, "one finger still down");
+        assert_eq!(t.feed(id(2), TouchPhase::End, p, 0.2), Some(Touch::Tap(2)));
+        assert!(!t.is_down());
+        // Three fingers.
+        for (n, at) in [(4, 0.0), (5, 0.02), (6, 0.04)] {
+            t.feed(id(n), TouchPhase::Start, p, 1.0 + at);
+        }
+        let ends: Vec<_> = [4, 5, 6].into_iter().map(|n| t.feed(id(n), TouchPhase::End, p, 1.2)).collect();
+        assert_eq!(ends, [None, None, Some(Touch::Tap(3))]);
+        assert_eq!((tap_command(2), tap_command(3), tap_command(1)), (Some("edit.undo"), Some("edit.redo"), None));
+    }
+
+    #[test]
+    fn a_pinch_a_long_press_a_cancel_or_one_finger_is_no_tap() {
+        let p = Pos2::new(100.0, 100.0);
+        let gesture = |moved: f32, held: f64, last: TouchPhase, fingers: u64| {
+            let mut t = Taps::default();
+            for n in 0..fingers {
+                t.feed(id(n), TouchPhase::Start, p, 0.0);
+            }
+            t.feed(id(0), TouchPhase::Move, p + egui::vec2(moved, 0.0), held / 2.0);
+            (0..fingers).filter_map(|n| t.feed(id(n), if n + 1 == fingers { last } else { TouchPhase::End }, p, held)).last()
+        };
+        assert_eq!(gesture(0.0, 0.2, TouchPhase::End, 2), Some(Touch::Tap(2)));
+        assert_eq!(gesture(40.0, 0.2, TouchPhase::End, 2), None, "a pinch");
+        assert_eq!(gesture(0.0, 0.9, TouchPhase::End, 2), None, "held too long");
+        assert_eq!(gesture(0.0, 0.2, TouchPhase::Cancel, 2), None, "cancelled");
+        assert_eq!(gesture(0.0, 0.2, TouchPhase::End, 1), None, "a pen or one finger");
+    }
+}
Author	SHA1	Message	Date
bflatasticandClaude Opus 5.5	aa125bfff1	Fix #585 : a two-finger tap undoes, a three-finger tap redoes Preferences › Devices › Enable Touch Gestures (on by default) was stored but nothing read it: no touch gesture was implemented. - `touch::Taps` follows the fingers egui reports (winit reads them from the system: WM_POINTER on Windows): fingers down together and lifted within half a second, none moved more than 16 points, is a tap. Two fingers undo, three redo, with the preference on. - egui makes the first finger the pointer too, so it has pressed on the canvas by the time a second lands: that press is dropped then (its tool interaction rolled back), and the rest of the gesture presses nothing. The tap so undoes what came before it, not the first finger's mark. - A pen is one contact, so pen strokes and taps are unaffected; pinch zoom is unchanged. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>	2026-10-09 05:39:47 +07:00
BFlat	e037064b2d	Merge pull request: land #616 (fix #597 ) Land #616 (fix #597: a browser-copied image pastes as the picture)	2026-10-09 05:31:24 +07:00
bflatastic	564a3ae662	Merge #616 : Fix #597 : an image copied in a browser pastes as the picture, not its address # Conflicts: # ROADMAP.md	2026-10-09 05:26:43 +07:00
BFlat	106abe639f	Merge pull request: land #612 , #610 , #611 Land #612 (fix #593), #610 (Shaper groups), #611 (per-paragraph attributes)	2026-10-09 05:25:17 +07:00
bflatasticandClaude Opus 5.5	54eed6ec4c	Fix #597 : an image copied in a browser pastes as the picture, not its address A browser's Copy Image puts the picture on the clipboard with the image's address as text (and HTML). Paste takes text before bitmaps, as word processors offer a picture of copied text, so it pasted the address. - `clipboard::is_address`: text that is only an address (http, https, file, ftp, data or blob). - Desktop paste (Windows, macOS, Linux): such text gives way to the clipboard's bitmap when it has one. An address alone pastes as text, as before; nothing is fetched. - Web: a paste whose text is only an address takes its picture file. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>	2026-10-09 05:22:09 +07:00