← board

feature: define Eliah's own layout in a streamed .lfm (dogfooding)

Goal

Eliah builds its window imperatively while the project ships a working .lfm streaming loader. Define Eliah's static layout (toolbar buttons, tree, editor, output, error list, designer paint-box, inspector, value edit — bounds + event bindings) in apps/ide/eliah/eliah.lfm and stream it via InitInheritedComponent (THandler becomes a TEliahForm(TForm) with published handlers; FindChild binds typed fields). Keep behaviour (menu, palette, designer paint, undo, reflow) in code. One-time work, beneficial forever.

apps/ide/eliah/eliah.lfm is committed as the starting artifact (the form + 16 child widgets with bounds + event names).

Streaming bugs surfaced (and the 3 already fixed)

The loader had only ever been exercised with a single TButton (Caption + OnClick). A real multi-widget form exposed:

  1. Method-backed properties never applied — SetOrdProp/SetStrProp only wrote direct-field props (SetKind=0); Caption/Left/Top/Width/Height use setter methods (SetKind=1) and were silently skipped. FIXED (typinfo invokes the setter). test_pcl_lfm now asserts the streamed captions.
  2. CreateInstance didn't zero the instance — reused heap left FHandle garbage; a pre-Realize FHandle<>nil check dereferenced junk. FIXED.
  3. Widgets relying on constructor-allocated arrays — TListBox/TComboBox SetLength FItems/FRows in their constructor, which streaming (CreateInstance) skips, leaving them nil → FItems[0] crash. FIXED (AddItem grows on demand; also drops the 256 cap).

4th blocker — FIXED 2026-06-23

A streamed TPaintBox had Canvas = nil (TPaintBox.Create makes FCanvas, which CreateInstance skips). ControlDrawTramp does paintBox.Canvas.Handle := cr on every expose → nil deref → segfault (an adjacent event-wired widget just shifted layout timing enough to trigger the draw). Fixed: TPaintBox.CreateHandle creates FCanvas if nil. Root-caused as Track B / lib, NOT resource inclusion (props streamed fine) and NOT the compiler (GetMethodAddr returns correct addresses).

Constructor-skip audit (2026-06-23)

All four blockers were the same theme: the streamer (CreateInstance) does NOT run constructors, and the loader had only ever been tested with a single TButton. Audited every PCL constructor:

The contract is now documented at lib/rtl/typinfo.pas:CreateInstance.

Remaining work

All streaming blockers are fixed. Only the re-application of the conversion is left: re-create the TEliahForm main.pas (the version that already passed --smoke; it only died on the now-fixed Canvas crash) and verify with an ffmpeg screenshot that the streamed layout renders + is interactive. eliah.lfm is committed and ready.

Note

The 4 streaming fixes benefit ALL RTTI streaming (and fixed the silently-empty captions in test_pcl_lfm), independent of Eliah.

DONE 2026-06-24 (commit 64f1526)

Eliah's whole window chrome now streams from apps/ide/eliah/eliah.lfm into TEliahForm via {$R}/InitInheritedComponent — toolbar (incl Link/OnClick) + the nested-TPaned splitter tree + every leaf widget. ~200 lines of imperative widget creation replaced by streaming (main.pas net -85 lines).

The ticket's premise was stale (written for the flat M0 layout; M1 rebuilt the window as a nested-TPaned tree). De-risked first with test/gui/test_pcl_stream_paned (now in gui_suite): proved deep nested TPaned streams, Realize recursively parents + packs TPaned slots by order, and published fields/methods bind — zero rtl/pcl changes needed beyond the already-landed streamer-adoption work.

Gates: garin 162/162, eliah --smoke OK, gui_suite OK, screenshot identical to the imperative build. The 4 old constructor-skip "blockers" were already obsoleted by the streamer adopting the metaclass virtual ctor (real ctors run; stopgaps reverted).