M3: Selection colors rows apply library color styles and create a style

A row's Styles menu lists this file's color styles (library copies are no
longer listed as local), then each enabled library's published color
styles under the library's name. Choosing a library style copies it in,
linked and read-only, and applies it to every fill and stroke the row
stands for in one undo step (selection.applyColorStyle with `library`).
A row linked to a style or variable now has the Styles button too, so it
can switch to another style.

Create style on an ordinary row opens a window with the next free
"Color n" name. Create makes a style of the row's whole paint (gradient
stops, opacity and blend mode included) and links it to every target in
one undo step (selection.createColorStyle {targets, name, description?}).
A name another style has, an empty name, or a row whose slots no longer
share one paint is refused, and the window stays open. Text ranges with
fills of their own take the style's value without a link.

docs/ui-parity.md

@@ -74,7 +74,7 @@ interaction feel not yet compared.
 | Transform box at small sizes | done | a press inside a layer smaller than its handles moves it, the nearest handle wins, handles answer just outside and are hidden under 16 px on screen; cursors follow each handle and the box's rotation |
 | Locked layers | done | selectable from the layers panel; no handles, not dragged with the rest of a selection |
 | Smart selection spacing | partial | with layers in a row, a column or an aligned grid selected, the Layout section shows horizontal and vertical spacing ("Mixed" until set; typed, scrubbed, fractional and negative) and pink handles in the gaps on the canvas drag them, one undo step, Escape cancels (`arrange.spacing`; sizes, parents and offsets within each track kept; at most 2,000 layers; flow children, locked layers and layers inside instances left out). A ring at each layer's centre drags it to another place in a regular row, column or complete top-left-aligned grid: the others close up and make room around it with the gaps kept, and with Cmd/Ctrl held the two layers swap places instead, previewed live while dragging (`selection_reorder_tests`; no ring on a layer under 16 px on screen). Not covered: reordering irregular grids, and several marked layers moved together. Checked by its author on macOS and in the app on Windows (#402) |
-| Selection colors | partial | for a mixed selection the Design panel lists their solid and gradient paints (children and text ranges included; hidden paints, masks, images, patterns and boolean operands left out; styles and variables listed apart): editing a colour changes every matching fill and stroke in one undo step, a row selects the layers that use it or applies a color style or color variable of the document, and a row linked to a style or variable detaches it, keeping the color (`selection.colors`, `selection.setPaint`, `selection.applyColorStyle`, `selection.bindColorVariable`, `selection.detachColor`, `selection.selectColor`). No library styles or variables from there, and no new style or variable from a row (#403) |
+| Selection colors | partial | for a mixed selection the Design panel lists their solid and gradient paints (children and text ranges included; hidden paints, masks, images, patterns and boolean operands left out; styles and variables listed apart): editing a colour changes every matching fill and stroke in one undo step, a row selects the layers that use it or applies a color style or color variable of the document, and a row linked to a style or variable detaches it, keeping the color (`selection.colors`, `selection.setPaint`, `selection.applyColorStyle`, `selection.bindColorVariable`, `selection.detachColor`, `selection.selectColor`). A row's Styles menu also lists each enabled library's published color styles under the library's name (a library that can't be read offers none), and a linked row's menu switches it to another style; a library style is copied in, linked and read-only, in the same undo step (`selection.applyColorStyle` with `library`). Create style on an ordinary row asks for a name (the next free "Color n" first) and makes a style of the row's whole paint, gradients, opacity and blend mode included, linked to every fill and stroke the row stands for in one undo step; a name in use keeps the window open (`selection.createColorStyle`). Text ranges with fills of their own take the style's value, without a link. No library variables from there, and no new variable from a row (#403) |
 | Keyboard box selection | done | Alt+Space on macOS, Ctrl+Space on Windows and Linux, or F8 (`select.area`): a box around the selection or in the middle of the view; arrows move it, Cmd/Ctrl+arrows or Shift+arrows size it (Shift with Cmd/Ctrl: farther), Enter selects like a marquee (Shift+Enter toggles, Cmd/Ctrl+Enter nested), Escape closes |
 
 ## Tools