Eliah — pane reflow / resizable splitters

• Type: feature (app / demo)
• Status: backlog
• Track: B
• Parent: feature-eliah-ide
• Blocked-by: feature-eliah-m0-window
• Opened: 2026-06-22

Motivation

M0 lays panes with absolute gtk_fixed bounds. The window is resizable but panes do not reflow, and there are no drag-splitters between panes. The IDE wants the tiled panes to track the window size (single sizable window — the whole point).

Options

• Recompute pane bounds on window size-allocate and re-SetBounds each pane (keeps gtk_fixed; needs a resize signal hook in PCL — may be a PCL gap).
• Add real GtkPaned (HPaned/VPaned) support to PCL for drag-splitters (bigger; benefits all PCL apps). If PCL can't express it → still app-side, but a PCL feature ticket may be the cleaner route.

Acceptance

Resizing the Eliah window reflows the panes to fill it; (stretch) draggable splitters between panes. No modal/subwindows introduced.

Log

• 2026-06-22 — filed from M0 caveat (absolute bounds, no reflow).
• 2026-06-23 — DONE (core). Took option 1: wired 'size-allocate' on the form's fixed container in pcl/gtk3widgets so TForm.OnResize fires with the content w/h (was a real PCL gap — only TPaintBox had it). eliah Relayout(w,h) recomputes all pane bounds on resize, clamped for tiny windows. Smoke-covered; full gui_suite green. STRETCH not done: draggable GtkPaned splitters — left as a separate future enhancement (bigger, benefits all PCL apps).