firka/flutter
firka/flutter
4
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Return the correct number of semantic children for the ListView.separated constructor (#48741)

Browse Source
This commit is contained in:
rami-a 2020-01-14 16:18:48 +00:00 committed by GitHub
parent b3ea191407
commit 68d0c89ffc
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
2 changed files with 52 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
packages/flutter/lib/src/widgets/scroll_view.dart
View File

@ -1051,7 +1051,7 @@ class ListView extends BoxScrollView {
}
return widget;
},
childCount: _computeSemanticChildCount(itemCount),
childCount: _computeActualChildCount(itemCount),
addAutomaticKeepAlives: addAutomaticKeepAlives,
addRepaintBoundaries: addRepaintBoundaries,
addSemanticIndexes: addSemanticIndexes,
@ -1069,7 +1069,7 @@ class ListView extends BoxScrollView {
shrinkWrap: shrinkWrap,
padding: padding,
cacheExtent: cacheExtent,
semanticChildCount: _computeSemanticChildCount(itemCount),
semanticChildCount: itemCount,
);
/// Creates a scrollable, linear array of widgets with a custom child model.
@ -1215,8 +1215,8 @@ class ListView extends BoxScrollView {
properties.add(DoubleProperty('itemExtent', itemExtent, defaultValue: null));
}
// Helper method to compute the semantic child count for the separated constructor.
static int _computeSemanticChildCount(int itemCount) {
// Helper method to compute the actual child count for the separated constructor.
static int _computeActualChildCount(int itemCount) {
return math.max(0, itemCount * 2 - 1);
}
}

48
packages/flutter/test/widgets/list_view_builder_test.dart
View File

@ -304,6 +304,54 @@ void main() {
expect(find.text('s5'), findsNothing);
expect(find.text('i6'), findsNothing);
});
testWidgets('ListView.separated uses correct semanticChildCount', (WidgetTester tester) async {
Widget buildFrame({int itemCount}) {
return Directionality(
textDirection: TextDirection.ltr,
child: ListView.separated(
itemCount: itemCount,
itemBuilder: (BuildContext context, int index) {
return SizedBox(
height: 100.0,
child: Text('i$index'),
);
},
separatorBuilder: (BuildContext context, int index) {
return SizedBox(
height: 10.0,
child: Text('s$index'),
);
},
),
);
}
Scrollable scrollable() {
return tester.widget<Scrollable>(
find.descendant(
of: find.byType(ListView),
matching: find.byType(Scrollable),
),
);
}
await tester.pumpWidget(buildFrame(itemCount: 0));
expect(scrollable().semanticChildCount, 0);
await tester.pumpWidget(buildFrame(itemCount: 1));
expect(scrollable().semanticChildCount, 1);
await tester.pumpWidget(buildFrame(itemCount: 2));
expect(scrollable().semanticChildCount, 2);
await tester.pumpWidget(buildFrame(itemCount: 3));
expect(scrollable().semanticChildCount, 3);
await tester.pumpWidget(buildFrame(itemCount: 4));
expect(scrollable().semanticChildCount, 4);
});
}
void check({ List<int> visible = const <int>[], List<int> hidden = const <int>[] }) {