#446 chunk D: Popups and overlays (tooltip, completion, ctx menu, dialog)

[JDonaghy]

Sub-task of #446 — Migrate GTK draw wiring to ScreenLayout::draw()

Scope (chunk 4 of 4): Popup and overlay surfaces

Migrate popup surfaces that already use pre-computed layout structs. These should be the easiest to migrate since their layout is computed independently of the rasteriser.

Surfaces:

• Tooltip — Surface::Tooltip, uses TooltipLayout
• Completion popup — Surface::Completions, uses CompletionsLayout
• Context menu — Surface::ContextMenu, uses ContextMenuLayout
• Dialog — Surface::Dialog, uses DialogLayout
• Rich text popup (hover) — Surface::RichTextPopup, uses RichTextPopupLayout
• Find/replace overlay — Surface::FindReplace
• Toast stack — Surface::Toast
• Palette (all pickers) — Surface::Palette

Note: These may be migratable independently of chunks B and C since they use their own layout structs. Could be done in parallel.

Branch: continue on issue-446-screen-layout-draw or separate branch if done in parallel.

Depends on

• #446 chunk A: Scaffolding + paint-only surfaces (no hit-test) #460 (chunk A — scaffolding must be in place)
• May NOT need quadraui#211 — popups use pre-computed layouts, not _layout() methods

Related

• Parent: Migrate GTK draw wiring to quadraui ScreenLayout::draw() #446
• Previous chunks: #446 chunk A: Scaffolding + paint-only surfaces (no hit-test) #460, #446 chunk B: Hit-test chrome surfaces (tab bars, status bars, breadcrumbs) #461, #446 chunk C: Complex surfaces (editor, scrollbars, terminal) #462

[JDonaghy]

Implementation notes (2026-05-18, coordinator)

Popups use pre-computed layout structs — they should NOT hit the same measurement divergence that broke chunk B. The pattern is:

// These already compute layout before paint:
Surface::Tooltip { tooltip, layout }      // TooltipLayout pre-computed
Surface::Completions { completions, layout } // CompletionsLayout pre-computed  
Surface::ContextMenu { menu, layout }     // ContextMenuLayout pre-computed
Surface::Dialog { dialog, layout }        // DialogLayout pre-computed
Surface::RichTextPopup { popup, layout }  // RichTextPopupLayout pre-computed

These surfaces pass their layout struct directly to Surface — no post-paint _layout() call needed. The FrameHitMap gives zone detection; the pre-computed layout gives fine-grained hit-test. This is the clean path.

Start with tooltips (simplest, no click dispatch needed), then completions (click dispatch exists via CompletionsLayout::hit_test), then work through the rest.

Use the same QScreenLayout alias pattern from PR #464. Build the frame in the draw closure, push surfaces, call frame.draw(b).

Pull quadraui first: cd ~/src/quadraui && git pull

Files: src/gtk/draw.rs only.

[JDonaghy]

Landed in PR #470. Rich text popup migration deferred to #469.