Bind JSX scroll listeners to their target node

[dogukani]

Problem

JSX onScroll listeners are delegated to Document::body(), but UI scroll events do not bubble. The native view scrolls while the Virtual List recycler and its scroll display remain stale.

Change

Bind JSX scroll listeners to their target node. Keep delegation for bubbling events and the existing document-level routes.

Verification

• Built the Virtual List Windows app using this compiler branch together with Dispatch virtual list scroll events core#57, Synchronize native scroll state with the UI tree windows#5, and Refresh virtual list rows after native scrolling examples#1. The previously broken build showed stale scroll state; the rebuilt app was manually retested and appears fixed.
• Compiler architecture, TypeScript, runtime-header syntax (native and 16-bit wchar_t), binding-composition, global-host-mutations, deferred-intrinsic-protocols, recursive-native-carriers, dynamic-value-metadata, value-contracts, and declaration-overlays checks passed.
• npm run gate remains red on this Windows checkout with broad emitted-baseline drift (157 corpus entries moved); the change is confined to the runtime header, which is included by emitted units rather than copied into their generated source. The drift has not been attributed to this patch, so the gate is not claimed as passing.
• test:hot-path-shapes cannot run with Windows Clang because the allocation-profile path requires <execinfo.h>.

The manually triggered Linux CI run passed: full compiler build, Hono C++ compilation, and byte-for-byte verification of both routes. Review and the emitted-gate baseline question remain before merge.

macOS and iOS

• Built the Virtual List example on macOS (Apple silicon, macOS 26.6.2) with this branch's rebuilt dist/cli.js (GEA_GEATSC_BIN), together with Dispatch virtual list scroll events core#57, Refresh virtual list rows after native scrolling examples#1 and Sync macOS scroll containers with the engine apple#1. The emitted runtime header contains the scroll target binding. Manual trackpad scrolling updated rows during movement, and captured frames showed no blank or mismatched rows.
• The same combination ran on an iPhone 16 Pro simulator (iOS 26.4), where rows updated during a slow drag.
• npm run gate was not run on macOS.

Summary by CodeRabbit

• Bug Fixes
  • Scroll event listeners now attach directly to their target, while other bubbling events continue to use BODY delegation.

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ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Advanced

Run ID: 6969ecea-b835-452c-a96d-900ef9624654

📥 Commits

Reviewing files that changed from the base of the PR and between e1ba2d5 and 869eb86.

📒 Files selected for processing (1)

• src/targets/cpp/runtime/gea_runtime.h

Included review availability: Your plan provides up to 10 included reviews per hour; 8 remain after this review.

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📝 Walkthrough

Walkthrough

bindNodeListener now registers scroll listeners on their target and returns before BODY delegation. The comment clarifies that bubbling events are delegated to BODY, while scroll events stay on their target.

Changes

Scroll Listener Targeting

Layer / File(s)	Summary
Listener registration behavior src/targets/cpp/runtime/gea_runtime.h	The comment distinguishes bubbling events delegated to BODY from scroll events. For scroll, bindNodeListener registers the listener on the target and returns.

Priority: ➖ Normal

Estimated code review effort: 2 (Simple) | ~8 minutes

Change: Bug fix

Suggested reviewers: dashersw

Merge Risk: ⚪ Minimal · up to 869eb

Scroll handlers now attach to their target so non-bubbling scroll events can be received. No concrete merge-blocking regression is established; engine-side listener cleanup could not be verified.

🚥 Pre-merge checks | ✅ 5

❌ Failed checks (1 inconclusive)

Check name	Status	Explanation	Resolution

✅ Passed checks (5 passed)

Check name	Status	Explanation
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check. Docstring coverage is scoped to functions touched by this diff. Analyzed 0 functions across 0…
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and concisely describes the main change: binding JSX scroll listeners to their target nodes.

✨ Finishing Touches

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🧪 Generate unit tests (beta)

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