Status: Implemented (landed 2026-04-23) Scope: Redesign the graph-canvas input/interaction features that the earlier egui_graphs-based implementations did not meet the project's standards bar for. These are explicitly not part of the egui_graphs retirement baseline — they need design work, not just plumbing rework.

Parent: ../../../archive_docs/checkpoint_2026-04-19/graphshell_docs/implementation_strategy/shell/2026-04-18_egui_graphs_retirement_plan.md (archived 2026-04-19)

Standards bar: Firefox-consistent where Firefox has a precedent, WAI-ARIA conformant for composite widgets, ergonomic for both pointer and keyboard users, modular (each feature independently gated and testable), effective (resolves a real user need).

---

Each feature below was in service before M2, was orphaned when M2 landed the graph-canvas live path, and is being re-landed on graph-canvas + CanvasCamera. The egui_graphs-era implementation does not meet the standards bar above as drawn. Each entry describes the gap and the redesign direction.

Previous shape: Right-drag rectangle selection, or Shift+Left-drag (user-preference gate).

Problems:

• Right-drag conflicts with Firefox's convention that right-click/right-drag surface a context menu. The current code suppresses the context menu when the lasso completes a drag, which is an active compensation.
• No keyboard equivalent — fails WAI-ARIA composite-widget selection patterns. Users who cannot use a pointer cannot perform multi-selection.

Redesign:

• Default pointer gesture: Shift+Left-drag rectangle select. Right-drag surfaces the context menu; remove the right-drag lasso default.
• Keep right-drag lasso as a user preference for power users, but not the default.
• Add keyboard multi-select: Shift+Arrow extends selection in spatial direction; Ctrl+Shift+A select all visible; Ctrl+A already exists.
• Route through ActionRegistry so bindings are user-remappable (per the project's Control UI/UX principle).
• Build against graph_canvas::engine::InteractionEngine's existing LassoBegin / LassoUpdate / LassoComplete state machine.

Previous shape: Tab / Shift+Tab cycles nodes in NodeIndex order.

Problems:

• NodeIndex order is arbitrary to the user — not spatial, not temporal, not semantic.
• No ARIA role/label on the graph surface; screen readers announce nothing.
• No focus-change live-region announcement.
• Tab cycles every node; WAI-ARIA composite-widget convention is that Tab enters/exits the widget while arrow keys navigate within.

Redesign:

• Graph surface gets role="application" (or role="graphicsdocument" if the assistive tech supports it) with aria-label describing the view.
• Arrow keys navigate spatially between visible nodes (nearest neighbor in the arrow direction, tie-break by index). This matches how every other graph editor works.
• Tab enters the graph surface (if not focused) or leaves it (if focused); does not cycle individual nodes.
• Focus change emits an ARIA live-region announcement with the focused node's accessibility name.
• Integrate with Graphshell's existing semantic-tagging system (render/semantic_tags.rs) for richer announcements.

Previous shape: Hover a node/edge, tooltip appears.

Problems:

• Hover-only affordance. Keyboard users never see it. Touch users never see it. Screen readers never announce it.
• Fails the project's Control UI/UX principle ("Every control surface must be operable with the active input mode without requiring the other").
• No dismiss affordance (Esc should close).

Redesign:

• Hover and focus both trigger the tooltip (for pointer and keyboard users respectively).
• Tooltip content exposed via aria-describedby on the focused node element (synthetic focus target in the graph surface's DOM-equivalent accessibility tree).
• Escape dismisses; pointer-leave / focus-leave dismisses.
• Live-region update on focus change (see 1.2).
• Consider integrating with the existing semantic badges in render/semantic_tags.rs to surface the same information in both the tooltip and the accessibility announcement.

Previous shape: Raw + / - keys trigger zoom; 0 resets.

Problems:

• Raw + / - conflicts with any text input on the graph surface (future inline edit, search-on-graph, etc.)
• Not Firefox-consistent. Firefox uses Ctrl+= / Ctrl+- / Ctrl+0.

Redesign:

• Rebind to Ctrl+= (zoom in), Ctrl+- (zoom out), Ctrl+0 (reset zoom).
• On macOS also accept Cmd+= / Cmd+- / Cmd+0.
• Route through ActionRegistry; user-remappable.
• Apply against CanvasCamera.zoom.
• Preserve the existing zoom clamp (0.1 to 10.0 or per-view min/max).

---

All four features above can land independently once the baseline retirement (parent plan) is complete. None blocks the others.

Prerequisites from the baseline:

• CanvasCamera is the single camera authority (baseline §1.C)
• canvas_bridge::collect_canvas_events handles all portable input translation (baseline §1.D)
• ProjectedScene::hit_proxies provides node/edge hit testing (already done)

Additional infrastructure to add in this follow-on:

• Semantic accessibility projection over ProjectedScene (needed for 1.2, 1.3)
• ActionRegistry entries for the new bindings (needed for 1.1, 1.4)
• Live-region host adapter (egui + iced) — placeholder trait, real implementation depends on each host's accessibility story

---

• Do not reintroduce the egui_graphs dependency for any of these features.
• Do not implement the egui host adapter's accessibility layer under the assumption that iced's layer will look the same — keep the portable seam minimal and let hosts supply their own AT integration.
• Do not design for Gamepad input in this follow-on; that's covered by the Control UI/UX plan.

---

• Plan created alongside egui_graphs retirement baseline.

• Default lasso gesture landed as Shift+Left-drag; right-drag remains available as a preference without owning the default graph-surface gesture.
• Spatial keyboard traversal landed on the graph surface: arrow keys move between visible nodes, Shift+Arrow extends selection, Ctrl+Shift+A selects visible nodes, and Ctrl+A remains select-all.
• Graph-surface focus announcements landed with semantic-tag and lifecycle detail, and the accessibility bridge now exposes the graph surface as an application-style canvas with descriptive keyboard guidance.
• Graph-surface tooltips now surface for hovered nodes and edges as well as focused nodes, support Escape dismissal, and clear once the hover/focus target changes.
• Zoom shortcuts now route through remappable bindings (Ctrl+=, Ctrl+-, Ctrl+0, with command-key parity where the binding system maps command to control semantics).