Preserve ResponsiveRow child state across Row/Wrap layout switches#6663
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Key each child's ControlWidget with a GlobalObjectKey tied to its Control identity so Flutter re-parents existing elements when the layout flips between Row and Wrap on a breakpoint change, instead of unmounting and re-inflating the subtree. Stateful descendants (video players, WebViews, scroll positions) now survive window resizes across breakpoints. Fixes #6661
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Description
ResponsiveRowControl.build()returns aRowwhen the resolvedcolvalues fit withincolumnsand aWrapwhen they don't. When a window resize crosses a breakpoint, the widget type at that slot changes, so Flutter's reconciliation unmounts the whole child subtree and inflates a new one — destroying any FlutterStatebelow (video players, WebViews, scroll positions, focus).This PR keys each child's
ControlWidgetwith aGlobalObjectKeytied to itsControlmodel identity. Since Dart-sideControlinstances are patched in place, the key is stable across rebuilds with no cache, and Flutter re-parents the existing elements into the newRow/Wrapwithin the same frame — child state now survives breakpoint changes.This also fixes a latent bug on the same line: the
ResponsiveRowControl's own widgetkeywas passed to every child'sControlWidget, which would produce duplicate-key errors if ever non-null.Verification
Scripted repro with a scrollable
ColumninsideResponsiveRow(scroll offset lives in FlutterState, same class of state as a video player's): scroll to 300, resize the window 900→500 px across the MD breakpoint, probe withscroll_to(delta=5).Before (0.86 client): offset resets to 0 on every Row↔Wrap flip (probe lands at 5).
After: offset is preserved (probe lands at 305, and 310 after flipping back).
Related issues
Fixes #6661
Summary by Sourcery
Preserve ResponsiveRow children’s widget state when switching between Row and Wrap layouts by stabilizing their identity-based keys.
Bug Fixes:
Enhancements: