notescraft/specs/editor-previews/tasks.md

Tasks: Editor previews: colors, external links, fenced diagrams and trees

Rules: each task is independently testable. Order = execution order. Every task ends with cargo test -p <crate>, cargo clippy -p <crate> --all-targets -- -D warnings and cargo fmt -p <crate> for the crates it touched; the last task runs cargo xtask ci (parts) and cargo xtask i18n.

• 1. Detect colors in text
  Files: crates/editor/src/preview/{mod.rs,color.rs}, crates/editor/src/lib.rs
  Done when: tests pass: hex 3/4/6/8 accepted, wrong lengths and non-hex rejected; rgb/rgba/hsl/hsla with valid arguments (alpha as 0-1 or percent) accepted, out-of-range or malformed arguments give none; Detected { range, rgb, alpha } ranges lie on char boundaries of accented and emoji text; a hex preceded or followed by an alphanumeric (word#abc123x) is skipped; lines over 4 KiB and notes over 2,000 colors are cut off without panic; a 1 MiB line is bounded.

• 2. Detect named colors in inline code
  Files: crates/editor/src/preview/named.rs
  Done when: tests pass: the 16 basic CSS names match as whole words (case-insensitive) only when the caller says the run is inline code and named colors are on; reddish, Red-ish and bored give none; each name maps to the exact CSS rgb.

• 3. Detect tree blocks
  Files: crates/editor/src/preview/tree.rs
  Done when: tests pass: detect_tree(label, body) accepts an empty, text or tree label with at least 2 lines of which at least 2 have a tree glyph (│ ├ └ ─ or the ASCII forms |--, '--, `--) followed by a name, returns rows { prefix, name, folder } (folder when the name ends in / or the next row is deeper); box-drawing tables, ASCII art and other labels are rejected; body over 64 KiB or 2,000 lines is rejected; copy text is not part of the result (the caller keeps the source).

• 4. Add preview settings
  Files: crates/engine/src/prefs/app_settings.rs, crates/engine/src/prefs/settings.rs (only if validation needs it), crates/engine/tests/settings.rs
  Done when: tests pass: EditorSettings.previews { colors: true, named_colors: false }, serde defaults for old files, settings.set of editor.previews.colors / editor.previews.named_colors round-trips through config.toml, bad types are refused.

• 5. Swatches in rendered rows
  Files: crates/ui-egui/src/views/note_view/{inlines.rs,painting.rs,select.rs,edit.rs}, crates/ui-egui/src/widgets/previews.rs, crates/ui-egui/src/shell/app/editor/blocks.rs
  Done when: tests pass: a plain-text or inline-code color gets a 12 pt rounded swatch (radius 3, one border, alpha composited) before it; #123 tags and invalid values get none; previews off draws none and skips detection; selecting across a swatch copies exactly the source and the caret byte offset equals the source; rows with inline math draw none; no NoteEdit is ever produced.

• 6. Swatches in fenced code
  Files: crates/ui-egui/src/views/note_view/blocks/code_card.rs
  Done when: tests pass: a css, scss, less, html, xml, svg, json, yaml, toml or ini fence draws swatches for its colors, a rust fence draws none.

• 7. Right-click color menu
  Files: crates/ui-egui/src/widgets/color_menu.rs, crates/ui-egui/src/text/views/note_view.rs, crates/i18n/locales/en.toml
  Done when: tests pass: secondary click on a swatch opens a menu with the color and hex, Copy color, Copy as rgb (clipboard text exact), Color previews switch and Named colors switch; each switch runs settings.set and the setting survives reload; the menu opens only inside a swatch rect.

• 8. External link arrow
  Files: crates/ui-egui/src/views/note_view/{inlines.rs,painting.rs}, crates/ui-egui/src/widgets/previews.rs
  Done when: tests pass: a markdown link to http:// or https:// is followed by a 16 pt up-right arrow in the link color, wikilinks and vault-relative links get none, clicking the link still returns the same clicked_link.

• 9. Tree card
  Files: crates/ui-egui/src/views/note_view/blocks/tree_card.rs, crates/ui-egui/src/views/note_view.rs, crates/ui-egui/src/text/views/note_view.rs
  Done when: tests pass: a qualifying fence draws a TREE card with Copy (clipboard equals the source bytes) and a folder or file icon per row; box-drawing tables and other fences stay ordinary code cards.

• 10. Mermaid Source/Diagram toggle, chips and fallbacks
  Files: crates/ui-egui/src/views/diagram_view.rs, crates/ui-egui/src/views/diagram_view/paint.rs, crates/ui-egui/src/views/note_view.rs, crates/ui-egui/src/views/center.rs, crates/ui-egui/src/shell/app/window/views.rs, crates/ui-egui/src/text/views/diagram_view.rs
  Done when: tests pass: a parseable mermaid fence shows as a diagram with a Source/Diagram toggle (default Diagram); Source shows the original text through the code card and edits go through the normal editing path; the choice is remembered per block while the note is open and survives an edit above the block; a parse error shows an error chip with the first message line, an unknown diagram kind an unsupported chip, and an over-limit diagram a size message, each leaving the source visible.

• 11. Docs, snapshot check and the gate
  Files: ROADMAP.md, docs/ARCHITECTURE.md
  Done when: a snapshot of a fixture note (colors, links, mermaid, tree) at 1440x900 in Mocha and Latte shows every preview; a 1,000-color note's detection stays under 10 ms (measured); cargo fmt --check, workspace clippy, cargo xtask layers, i18n, tree are green and the test suites of the touched crates pass; ROADMAP and ARCHITECTURE describe the new module and settings.