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// Copyright 2014 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
import 'package:flutter/rendering.dart';
import 'package:flutter/widgets.dart';
import 'package:flutter_test/flutter_test.dart';
class TestFlowDelegate extends FlowDelegate {
TestFlowDelegate({required this.startOffset}) : super(repaint: startOffset);
final Animation<double> startOffset;
@override
BoxConstraints getConstraintsForChild(int i, BoxConstraints constraints) {
return constraints.loosen();
}
@override
void paintChildren(FlowPaintingContext context) {
double dy = startOffset.value;
for (int i = 0; i < context.childCount; ++i) {
context.paintChild(i, transform: Matrix4.translationValues(0.0, dy, 0.0));
dy += 0.75 * context.getChildSize(i)!.height;
}
}
@override
bool shouldRepaint(TestFlowDelegate oldDelegate) => startOffset == oldDelegate.startOffset;
}
class OpacityFlowDelegate extends FlowDelegate {
OpacityFlowDelegate(this.opacity);
double opacity;
@override
void paintChildren(FlowPaintingContext context) {
for (int i = 0; i < context.childCount; ++i) {
context.paintChild(i, opacity: opacity);
}
}
@override
bool shouldRepaint(OpacityFlowDelegate oldDelegate) => opacity != oldDelegate.opacity;
}
// OpacityFlowDelegate that paints one of its children twice
class DuplicatePainterOpacityFlowDelegate extends OpacityFlowDelegate {
DuplicatePainterOpacityFlowDelegate(double opacity) : super(opacity);
@override
void paintChildren(FlowPaintingContext context) {
for (int i = 0; i < context.childCount; ++i) {
context.paintChild(i, opacity: opacity);
}
if (context.childCount > 0) {
context.paintChild(0, opacity: opacity);
}
}
}
void main() {
testWidgets('Flow control test', (WidgetTester tester) async {
final AnimationController startOffset = AnimationController.unbounded(
vsync: tester,
);
final List<int> log = <int>[];
Widget buildBox(int i) {
return GestureDetector(
onTap: () {
log.add(i);
},
child: Container(
width: 100.0,
height: 100.0,
color: const Color(0xFF0000FF),
child: Text('$i', textDirection: TextDirection.ltr),
),
);
}
await tester.pumpWidget(
Flow(
delegate: TestFlowDelegate(startOffset: startOffset),
children: <Widget>[
buildBox(0),
buildBox(1),
buildBox(2),
buildBox(3),
buildBox(4),
buildBox(5),
buildBox(6),
],
),
);
await tester.tap(find.text('0'));
expect(log, equals(<int>[0]));
await tester.tap(find.text('1'));
expect(log, equals(<int>[0, 1]));
await tester.tap(find.text('2'));
expect(log, equals(<int>[0, 1, 2]));
log.clear();
await tester.tapAt(const Offset(20.0, 90.0));
expect(log, equals(<int>[1]));
startOffset.value = 50.0;
await tester.pump();
log.clear();
await tester.tapAt(const Offset(20.0, 90.0));
expect(log, equals(<int>[0]));
});
testWidgets('paintChild gets called twice', (WidgetTester tester) async {
await tester.pumpWidget(
Flow(
delegate: DuplicatePainterOpacityFlowDelegate(1.0),
children: const <Widget>[
SizedBox(width: 100.0, height: 100.0),
SizedBox(width: 100.0, height: 100.0),
],
),
);
final dynamic exception = tester.takeException();
expect(exception, isFlutterError);
final FlutterError error = exception as FlutterError;
expect(error.toStringDeep(), equalsIgnoringHashCodes(
'FlutterError\n'
' Cannot call paintChild twice for the same child.\n'
' The flow delegate of type DuplicatePainterOpacityFlowDelegate\n'
' attempted to paint child 0 multiple times, which is not\n'
' permitted.\n',
));
});
testWidgets('Flow opacity layer', (WidgetTester tester) async {
const double opacity = 0.2;
await tester.pumpWidget(
Flow(
delegate: OpacityFlowDelegate(opacity),
children: const <Widget>[
SizedBox(width: 100.0, height: 100.0),
],
),
);
ContainerLayer? layer = RendererBinding.instance!.renderView.debugLayer;
while (layer != null && layer is! OpacityLayer)
layer = layer.firstChild as ContainerLayer?;
expect(layer, isA<OpacityLayer>());
final OpacityLayer? opacityLayer = layer as OpacityLayer?;
expect(opacityLayer!.alpha, equals(opacity * 255));
expect(layer!.firstChild, isA<TransformLayer>());
});
testWidgets('Flow can set and update clipBehavior', (WidgetTester tester) async {
const double opacity = 0.2;
await tester.pumpWidget(
Flow(
delegate: OpacityFlowDelegate(opacity),
children: const <Widget>[
SizedBox(width: 100.0, height: 100.0),
],
),
);
// By default, clipBehavior should be Clip.hardEdge
final RenderFlow renderObject = tester.renderObject(find.byType(Flow));
expect(renderObject.clipBehavior, equals(Clip.hardEdge));
for(final Clip clip in Clip.values) {
await tester.pumpWidget(
Flow(
delegate: OpacityFlowDelegate(opacity),
children: const <Widget>[
SizedBox(width: 100.0, height: 100.0),
],
clipBehavior: clip,
),
);
expect(renderObject.clipBehavior, clip);
}
});
testWidgets('Flow.unwrapped can set and update clipBehavior', (WidgetTester tester) async {
const double opacity = 0.2;
await tester.pumpWidget(
Flow.unwrapped(
delegate: OpacityFlowDelegate(opacity),
children: const <Widget>[
SizedBox(width: 100.0, height: 100.0),
],
),
);
// By default, clipBehavior should be Clip.hardEdge
final RenderFlow renderObject = tester.renderObject(find.byType(Flow));
expect(renderObject.clipBehavior, equals(Clip.hardEdge));
for(final Clip clip in Clip.values) {
await tester.pumpWidget(
Flow.unwrapped(
delegate: OpacityFlowDelegate(opacity),
children: const <Widget>[
SizedBox(width: 100.0, height: 100.0),
],
clipBehavior: clip,
),
);
expect(renderObject.clipBehavior, clip);
}
});
}