zhongliugo 7bafe12c4f
[web] Fix scroll event bubbling in iframes (#179703)
Fixes scroll event bubbling when Flutter web is embedded in an
iframe(#156985).

When a scrollable handles a wheel event, it now calls
respond(allowPlatformDefault: false) to signal the engine.

In iframe mode, the engine always calls preventDefault() to block native
scroll chaining, then uses postMessage to explicitly scroll the parent
page only when all scrollables are at boundary

Before change:
https://issue-156985-before.web.app/

After change:
https://issue-156985-after.web.app/
2026-02-12 21:25:13 +00:00
..