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Make sure to sync the widgets even when we don't do a relayout.

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R=abarth@chromium.org

Review URL: https://codereview.chromium.org/1225093007 .
This commit is contained in:
Hixie 2015-07-09 13:06:36 -07:00
parent c73f65312b
commit 61c2a1695b
1 changed files with 27 additions and 1 deletions
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28
sdk/lib/widgets/block_viewport.dart
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@ -81,6 +81,8 @@ class BlockViewport extends RenderObjectWrapper {
// end of the last one. If there's no children, then the only offset
// is 0.0.
List<double> _offsets = <double>[0.0];
int _currentStartIndex = 0;
int _currentChildCount = 0;
int _findIndexForOffsetBeforeOrAt(double offset) {
int left = 0;
@ -117,8 +119,28 @@ class BlockViewport extends RenderObjectWrapper {
void syncRenderObject(BlockViewport old) {
super.syncRenderObject(old);
if (_dirty)
if (_dirty) {
root.markNeedsLayout();
} else {
if (_currentChildCount > 0) {
assert(_currentStartIndex >= 0);
assert(builder != null);
assert(root != null);
int lastIndex = _currentStartIndex + _currentChildCount;
for (int index = _currentStartIndex; index <= lastIndex; index += 1) {
Widget widget = builder(index);
assert(widget != null);
assert(widget.key != null);
_Key key = new _Key.fromWidget(widget);
Widget oldWidget = _childrenByKey[key];
assert(oldWidget != null);
assert(oldWidget.root.parent == root);
widget = syncChild(widget, oldWidget, root.childAfter(oldWidget.root));
assert(widget != null);
_childrenByKey[key] = widget;
}
}
}
}
Widget _getWidget(int index, BoxConstraints innerConstraints) {
@ -149,6 +171,8 @@ class BlockViewport extends RenderObjectWrapper {
}
void layout(BoxConstraints constraints) {
if (!_dirty)
return;
_dirty = false;
Map<_Key, Widget> newChildren = new Map<_Key, Widget>();
@ -261,6 +285,8 @@ class BlockViewport extends RenderObjectWrapper {
}
_childrenByKey = newChildren;
_currentStartIndex = startIndex;
_currentChildCount = _childrenByKey.length;
}
}