feature: Eliah shared selection model — designer ↔ editor link (+ AI rail)

• Type: feature (Track B)
• Status: backlog
• Track: B
• Parent: feature-eliah-shell
• Opened: 2026-06-23

Goal

One shared, bidirectional selection/command model wired across the designer and the editor. Selecting a component anywhere highlights it everywhere; commands (rename, wire event, and future AI actions) operate on this model, never on layout state.

Why

The thing Delphi/Lazarus did adequately and is the real IDE value. Make it first-class and explicit so it stays clean and so AI tooling has a rail to ride.

Scope

• Selection model (render-agnostic, in garin): "current selection" = a set of component ids in the active form's doc model, with change events.
• Designer → editor: selecting a widget in the designer scrolls/highlights its creation + event-handler code in the editor.
• Editor → designer: placing the caret on a component identifier selects that component in the designer.
• Command surface: actions take the selection (e.g. "wire OnClick" generates a handler stub + assigns it; "rename" updates code + .lfm + doc model together).
• AI rail (stub only here): AI tooling is a command source + a console pane, emitting the same commands ("link button click to SaveFile"). No layout or mode special-casing — it operates on selection + doc model like any command.

Acceptance

Designer selection moves the editor caret to the matching code and vice-versa; at least one command (wire OnClick stub) works end-to-end through the selection model; the command surface is documented so AI/menus/shortcuts are interchangeable sources. gui_suite + garin green (selection model unit-tested headless via bochan); screenshot of linked selection.

Notes

• Keep the selection model in apps/ide/garin (render-agnostic, bochan-testable), faces (eliah/ilja) subscribe.
• Event-handler wiring touches code generation; reuse garin/lfmload + buffer/editor mutation. Mind the streamer/RTTI path.

Log

• 2026-06-23 — filed (milestone 5 of feature-eliah-shell).

Progress 2026-06-24 — shared model + bidirectional link landed

Foundation (commit a74c646, garin, bochan-tested):

• docmodel node Name (the object <Name>: identifier) — captured + emitted by lfmload (was discarded); FindByName.
• garin/selection.TSelectionModel: shared current selection (index) + Select/SelectByName/Clear/SelectedName/change-count.
• selection.LfmFindObjectLine / LfmObjectNameAt: component name <-> .lfm line.

Wiring (commit 1ce2032, eliah + lib/pcl):

• THandler.Sel routes all selections through the model (synced on doc swap).
• Designer -> editor: select a node -> editor loads the design .lfm + scrolls (TMemo.CaretToLine) to its object <Name> line.
• Editor -> designer: 'Link' toolbar button reads the caret line (new TMemo.CaretLine + TWidgetSet.MemoCaretLine virtual + gtk get_iter_at_mark/ iter_get_line bindings) and selects the component declared there.
• The 'Link' button is one command source on the shared model — menus/shortcuts/AI are interchangeable sources.

Gates: garin 157/157, eliah --smoke OK (both directions, deterministic via SelectFromEditorLine), gui_suite OK, screenshot shows the Link button.

Remaining (keeps this ticket open)

• wire-OnClick command: generate a handler stub + assignment (touches .pas codegen); the example end-to-end command from the acceptance.
• AI rail + console pane (stub): an AI command source emitting the same selection/command ops; no layout special-casing.
• Command-surface doc: short note so AI/menus/shortcuts are documented as interchangeable sources.
• Editor->designer on caret move (not just the button): wants a TMemo caret/ click signal; the button covers it for now.
• Link currently keys on the .lfm object declaration (the box-emulation creation site); .pas event-handler navigation arrives with wire-OnClick.

DONE 2026-06-24

Wire-OnClick command landed (commit after 1bff46b): selecting a component + 'OnClick' assigns OnClick = <Name>Click (round-trips in the .lfm, shows in the inspector) and generates an undoable handler stub in the editor (idempotent). Command surface documented (devdocs/developer/eliah-command-surface.md). AI rail split to a suggestion ticket (backlog/feature-eliah-ai-command-rail) per the decision that it mainly adds networking, little local-test value.

M5 acceptance met: designer<->editor selection link both directions; one command (wire OnClick) end-to-end through the shared model; command surface documented (menu/shortcut/AI interchangeable). Gates: garin 162/162, eliah --smoke OK, gui_suite OK, screenshots of Link + OnClick.

Deferred (own tickets / minor):

• AI command rail + console pane — backlog/feature-eliah-ai-command-rail.
• editor->designer on caret move (not just the Link button) — wants a TMemo caret/click signal; the button covers it.
• .pas event-handler navigation (the link keys on the .lfm object declaration = the box-emulation creation site); the wire command already seeds .pas stubs.