Redo: Modal dismissed by any button (#36956)
This PR makes ModalBarrier dismiss modal with any button press instead of primary button up, by making it use a private recognizer _AnyTapGestureRecognizer that is similar to TapGestureRecognizer but accepts gestures by any single button.
diff --git a/packages/flutter/lib/src/widgets/modal_barrier.dart b/packages/flutter/lib/src/widgets/modal_barrier.dart
index 567a7f9..37b66e5 100644
--- a/packages/flutter/lib/src/widgets/modal_barrier.dart
+++ b/packages/flutter/lib/src/widgets/modal_barrier.dart
@@ -3,6 +3,7 @@
// found in the LICENSE file.
import 'package:flutter/foundation.dart';
+import 'package:flutter/gestures.dart';
import 'basic.dart';
import 'container.dart';
@@ -81,12 +82,11 @@
// On Android, the back button is used to dismiss a modal. On iOS, some
// modal barriers are not dismissible in accessibility mode.
excluding: !semanticsDismissible || !modalBarrierSemanticsDismissible,
- child: GestureDetector(
- onTapDown: (TapDownDetails details) {
+ child: _ModalBarrierGestureDetector(
+ onAnyTapDown: () {
if (dismissible)
Navigator.maybePop(context);
},
- behavior: HitTestBehavior.opaque,
child: Semantics(
label: semanticsDismissible ? semanticsLabel : null,
textDirection: semanticsDismissible && semanticsLabel != null ? Directionality.of(context) : null,
@@ -175,3 +175,162 @@
);
}
}
+
+// Recognizes tap down by any pointer button.
+//
+// It is similar to [TapGestureRecognizer.onTapDown], but accepts any single
+// button, which means the gesture also takes parts in gesture arenas.
+class _AnyTapGestureRecognizer extends PrimaryPointerGestureRecognizer {
+ _AnyTapGestureRecognizer({
+ Object debugOwner,
+ }) : super(debugOwner: debugOwner);
+
+ VoidCallback onAnyTapDown;
+
+ bool _sentTapDown = false;
+ bool _wonArenaForPrimaryPointer = false;
+ // The buttons sent by `PointerDownEvent`. If a `PointerMoveEvent` comes with a
+ // different set of buttons, the gesture is canceled.
+ int _initialButtons;
+
+ @override
+ void addAllowedPointer(PointerDownEvent event) {
+ super.addAllowedPointer(event);
+ // `_initialButtons` must be assigned here instead of `handlePrimaryPointer`,
+ // because `acceptGesture` might be called before `handlePrimaryPointer`,
+ // which relies on `_initialButtons` to create `TapDownDetails`.
+ _initialButtons = event.buttons;
+ }
+
+ @override
+ void handlePrimaryPointer(PointerEvent event) {
+ if (event is PointerUpEvent || event is PointerCancelEvent) {
+ resolve(GestureDisposition.rejected);
+ _reset();
+ } else if (event.buttons != _initialButtons) {
+ resolve(GestureDisposition.rejected);
+ stopTrackingPointer(primaryPointer);
+ }
+ }
+
+ @override
+ void resolve(GestureDisposition disposition) {
+ if (_wonArenaForPrimaryPointer && disposition == GestureDisposition.rejected) {
+ // This can happen if the gesture has been canceled. For example, when
+ // the pointer has exceeded the touch slop, the buttons have been changed,
+ // or if the recognizer is disposed.
+ assert(_sentTapDown);
+ _reset();
+ }
+ super.resolve(disposition);
+ }
+
+ @override
+ void didExceedDeadlineWithEvent(PointerDownEvent event) {
+ _checkDown(event.pointer);
+ }
+
+ @override
+ void acceptGesture(int pointer) {
+ super.acceptGesture(pointer);
+ if (pointer == primaryPointer) {
+ _checkDown(pointer);
+ _wonArenaForPrimaryPointer = true;
+ _reset();
+ }
+ }
+
+ @override
+ void rejectGesture(int pointer) {
+ super.rejectGesture(pointer);
+ if (pointer == primaryPointer) {
+ // Another gesture won the arena.
+ assert(state != GestureRecognizerState.possible);
+ _reset();
+ }
+ }
+
+ void _checkDown(int pointer) {
+ if (_sentTapDown)
+ return;
+ if (onAnyTapDown != null)
+ onAnyTapDown();
+ _sentTapDown = true;
+ }
+
+ void _reset() {
+ _sentTapDown = false;
+ _wonArenaForPrimaryPointer = false;
+ _initialButtons = null;
+ }
+
+ @override
+ String get debugDescription => 'any tap';
+
+ @override
+ void debugFillProperties(DiagnosticPropertiesBuilder properties) {
+ super.debugFillProperties(properties);
+ properties.add(FlagProperty('wonArenaForPrimaryPointer', value: _wonArenaForPrimaryPointer, ifTrue: 'won arena'));
+ properties.add(FlagProperty('sentTapDown', value: _sentTapDown, ifTrue: 'sent tap down'));
+ }
+}
+
+class _ModalBarrierSemanticsDelegate extends SemanticsGestureDelegate {
+ const _ModalBarrierSemanticsDelegate({this.onAnyTapDown});
+
+ final VoidCallback onAnyTapDown;
+
+ @override
+ void assignSemantics(RenderSemanticsGestureHandler renderObject) {
+ renderObject.onTap = onAnyTapDown;
+ }
+}
+
+
+class _AnyTapGestureRecognizerFactory extends GestureRecognizerFactory<_AnyTapGestureRecognizer> {
+ const _AnyTapGestureRecognizerFactory({this.onAnyTapDown});
+
+ final VoidCallback onAnyTapDown;
+
+ @override
+ _AnyTapGestureRecognizer constructor() => _AnyTapGestureRecognizer();
+
+ @override
+ void initializer(_AnyTapGestureRecognizer instance) {
+ instance.onAnyTapDown = onAnyTapDown;
+ }
+}
+
+// A GestureDetector used by ModalBarrier. It only has one callback,
+// [onAnyTapDown], which recognizes tap down unconditionally.
+class _ModalBarrierGestureDetector extends StatelessWidget {
+ const _ModalBarrierGestureDetector({
+ Key key,
+ @required this.child,
+ @required this.onAnyTapDown,
+ }) : assert(child != null),
+ assert(onAnyTapDown != null),
+ super(key: key);
+
+ /// The widget below this widget in the tree.
+ /// See [RawGestureDetector.child].
+ final Widget child;
+
+ /// Immediately called when a pointer causes a tap down.
+ /// See [_AnyTapGestureRecognizer.onAnyTapDown].
+ final VoidCallback onAnyTapDown;
+
+ @override
+ Widget build(BuildContext context) {
+ final Map<Type, GestureRecognizerFactory> gestures = <Type, GestureRecognizerFactory>{
+ _AnyTapGestureRecognizer: _AnyTapGestureRecognizerFactory(onAnyTapDown: onAnyTapDown),
+ };
+
+ return RawGestureDetector(
+ gestures: gestures,
+ behavior: HitTestBehavior.opaque,
+ semantics: _ModalBarrierSemanticsDelegate(onAnyTapDown: onAnyTapDown),
+ child: child,
+ );
+ }
+}
diff --git a/packages/flutter/test/widgets/modal_barrier_test.dart b/packages/flutter/test/widgets/modal_barrier_test.dart
index d80ec98..cc5c267 100644
--- a/packages/flutter/test/widgets/modal_barrier_test.dart
+++ b/packages/flutter/test/widgets/modal_barrier_test.dart
@@ -7,6 +7,7 @@
import 'package:flutter/material.dart';
import 'package:flutter/rendering.dart';
import 'package:flutter/widgets.dart';
+import 'package:flutter/gestures.dart' show kSecondaryButton;
import 'semantics_tester.dart';
@@ -41,7 +42,7 @@
await tester.tap(find.text('target'));
await tester.pumpWidget(subject);
expect(tapped, isFalse,
- reason: 'because the tap is prevented by ModalBarrier');
+ reason: 'because the tap is not prevented by ModalBarrier');
});
testWidgets('ModalBarrier does not prevent interactions with widgets in front of it', (WidgetTester tester) async {
@@ -57,10 +58,38 @@
await tester.tap(find.text('target'));
await tester.pumpWidget(subject);
expect(tapped, isTrue,
- reason: 'because the tap is not prevented by ModalBarrier');
+ reason: 'because the tap is prevented by ModalBarrier');
});
- testWidgets('ModalBarrier pops the Navigator when dismissed', (WidgetTester tester) async {
+ testWidgets('ModalBarrier does not prevent interactions with translucent widgets in front of it', (WidgetTester tester) async {
+ bool dragged = false;
+ final Widget subject = Stack(
+ textDirection: TextDirection.ltr,
+ children: <Widget>[
+ const ModalBarrier(dismissible: false),
+ GestureDetector(
+ behavior: HitTestBehavior.translucent,
+ onHorizontalDragStart: (_) {
+ dragged = true;
+ },
+ child: const Center(
+ child: Text('target', textDirection: TextDirection.ltr),
+ ),
+ ),
+ ],
+ );
+
+ await tester.pumpWidget(subject);
+ await tester.dragFrom(
+ tester.getBottomRight(find.byType(GestureDetector)) - const Offset(10, 10),
+ const Offset(-20, 0),
+ );
+ await tester.pumpWidget(subject);
+ expect(dragged, isTrue,
+ reason: 'because the drag is prevented by ModalBarrier');
+ });
+
+ testWidgets('ModalBarrier pops the Navigator when dismissed by primay tap', (WidgetTester tester) async {
final Map<String, WidgetBuilder> routes = <String, WidgetBuilder>{
'/': (BuildContext context) => FirstWidget(),
'/modal': (BuildContext context) => SecondWidget(),
@@ -85,6 +114,56 @@
reason: 'The route should have been dismissed by tapping the barrier.');
});
+ testWidgets('ModalBarrier pops the Navigator when dismissed by primary tap down', (WidgetTester tester) async {
+ final Map<String, WidgetBuilder> routes = <String, WidgetBuilder>{
+ '/': (BuildContext context) => FirstWidget(),
+ '/modal': (BuildContext context) => SecondWidget(),
+ };
+
+ await tester.pumpWidget(MaterialApp(routes: routes));
+
+ // Initially the barrier is not visible
+ expect(find.byKey(const ValueKey<String>('barrier')), findsNothing);
+
+ // Tapping on X routes to the barrier
+ await tester.tap(find.text('X'));
+ await tester.pump(); // begin transition
+ await tester.pump(const Duration(seconds: 1)); // end transition
+
+ // Tap on the barrier to dismiss it
+ await tester.press(find.byKey(const ValueKey<String>('barrier')));
+ await tester.pump(); // begin transition
+ await tester.pump(const Duration(seconds: 1)); // end transition
+
+ expect(find.byKey(const ValueKey<String>('barrier')), findsNothing,
+ reason: 'The route should have been dismissed by tapping the barrier.');
+ });
+
+ testWidgets('ModalBarrier pops the Navigator when dismissed by non-primary tap down', (WidgetTester tester) async {
+ final Map<String, WidgetBuilder> routes = <String, WidgetBuilder>{
+ '/': (BuildContext context) => FirstWidget(),
+ '/modal': (BuildContext context) => SecondWidget(),
+ };
+
+ await tester.pumpWidget(MaterialApp(routes: routes));
+
+ // Initially the barrier is not visible
+ expect(find.byKey(const ValueKey<String>('barrier')), findsNothing);
+
+ // Tapping on X routes to the barrier
+ await tester.tap(find.text('X'));
+ await tester.pump(); // begin transition
+ await tester.pump(const Duration(seconds: 1)); // end transition
+
+ // Tap on the barrier to dismiss it
+ await tester.press(find.byKey(const ValueKey<String>('barrier')), buttons: kSecondaryButton);
+ await tester.pump(); // begin transition
+ await tester.pump(const Duration(seconds: 1)); // end transition
+
+ expect(find.byKey(const ValueKey<String>('barrier')), findsNothing,
+ reason: 'The route should have been dismissed by tapping the barrier.');
+ });
+
testWidgets('ModalBarrier does not pop the Navigator with a WillPopScope that returns false', (WidgetTester tester) async {
bool willPopCalled = false;
final Map<String, WidgetBuilder> routes = <String, WidgetBuilder>{
