Do not add spacing to the first child's width in RenderWrap line wrapping (#15272)
The first child fits on the line if the line can accomodate its width.
After the first child the line needs room for the child's width plus spacing.
diff --git a/packages/flutter/lib/src/rendering/wrap.dart b/packages/flutter/lib/src/rendering/wrap.dart
index b97e44f..bfde260 100644
--- a/packages/flutter/lib/src/rendering/wrap.dart
+++ b/packages/flutter/lib/src/rendering/wrap.dart
@@ -608,8 +608,7 @@
child.layout(childConstraints, parentUsesSize: true);
final double childMainAxisExtent = _getMainAxisExtent(child);
final double childCrossAxisExtent = _getCrossAxisExtent(child);
- if (runMainAxisExtent + childMainAxisExtent + spacing > mainAxisLimit) {
- assert(childCount > 0);
+ if (childCount > 0 && runMainAxisExtent + spacing + childMainAxisExtent > mainAxisLimit) {
mainAxisExtent = math.max(mainAxisExtent, runMainAxisExtent);
crossAxisExtent += runCrossAxisExtent;
if (runMetrics.isNotEmpty)
diff --git a/packages/flutter/test/widgets/wrap_test.dart b/packages/flutter/test/widgets/wrap_test.dart
index 3cf2088..174604a 100644
--- a/packages/flutter/test/widgets/wrap_test.dart
+++ b/packages/flutter/test/widgets/wrap_test.dart
@@ -851,4 +851,19 @@
const Offset(0.0, 20.0)
]);
});
+
+ testWidgets('Object exactly matches container width', (WidgetTester tester) async {
+ await tester.pumpWidget(new Wrap(
+ direction: Axis.horizontal,
+ textDirection: TextDirection.ltr,
+ spacing: 10.0,
+ runSpacing: 10.0,
+ children: <Widget>[
+ const SizedBox(width: 800.0, height: 0.0),
+ ],
+ ));
+
+ expect(tester.renderObject<RenderBox>(find.byType(Wrap)).size, equals(const Size(800.0, 600.0)));
+ verify(tester, <Offset>[const Offset(0.0, 0.0)]);
+ });
}
