[animations] added onClosed (#122)

Author: The-Redhat

packages/animations/lib/src/open_container.dart

@@ -66,6 +66,7 @@ class OpenContainer extends StatefulWidget {
       borderRadius: BorderRadius.all(Radius.circular(4.0)),
     ),
     this.openShape = const RoundedRectangleBorder(),
+    this.onClosed,
     @required this.closedBuilder,
     @required this.openBuilder,
     this.tappable = true,
@@ -163,6 +164,9 @@ class OpenContainer extends StatefulWidget {
   ///  * [Material.shape], which is used to implement this property.
   final ShapeBorder openShape;
 
+  /// Called when the container was popped and has returned to the closed state.
+  final VoidCallback onClosed;
+
   /// Called to obtain the child for the container in the closed state.
   ///
   /// The [Widget] returned by this builder is faded out when the container
@@ -220,8 +224,8 @@ class _OpenContainerState extends State<OpenContainer> {
   // same widget included in the [_OpenContainerRoute] where it fades out.
   final GlobalKey _closedBuilderKey = GlobalKey();
 
-  void openContainer() {
-    Navigator.of(context).push(_OpenContainerRoute(
+  Future<void> openContainer<T>() async {
+    await Navigator.of(context).push(_OpenContainerRoute(
       closedColor: widget.closedColor,
       openColor: widget.openColor,
       closedElevation: widget.closedElevation,
@@ -235,6 +239,9 @@ class _OpenContainerState extends State<OpenContainer> {
       transitionDuration: widget.transitionDuration,
       transitionType: widget.transitionType,
     ));
+    if (widget.onClosed != null) {
+      widget.onClosed();
+    }
   }
 
   @override

packages/animations/test/open_container_test.dart

@@ -1448,6 +1448,48 @@ void main() {
     expect(find.text('Closed 2'), findsNothing);
     expect(find.text('Open 2'), findsOneWidget);
   });
+  testWidgets('onClosed callback is called when container has closed',
+      (WidgetTester tester) async {
+    bool hasClosed = false;
+    final Widget openContainer = OpenContainer(
+      onClosed: () {
+        hasClosed = true;
+      },
+      closedBuilder: (BuildContext context, VoidCallback action) {
+        return GestureDetector(
+          onTap: action,
+          child: const Text('Closed'),
+        );
+      },
+      openBuilder: (BuildContext context, VoidCallback action) {
+        return GestureDetector(
+          onTap: action,
+          child: const Text('Open'),
+        );
+      },
+    );
+
+    await tester.pumpWidget(
+      _boilerplate(child: openContainer),
+    );
+
+    expect(find.text('Open'), findsNothing);
+    expect(find.text('Closed'), findsOneWidget);
+    expect(hasClosed, isFalse);
+
+    await tester.tap(find.text('Closed'));
+    await tester.pumpAndSettle();
+
+    expect(find.text('Open'), findsOneWidget);
+    expect(find.text('Closed'), findsNothing);
+
+    await tester.tap(find.text('Open'));
+    await tester.pumpAndSettle();
+
+    expect(find.text('Open'), findsNothing);
+    expect(find.text('Closed'), findsOneWidget);
+    expect(hasClosed, isTrue);
+  });
 }
 
 Color _getScrimColor(WidgetTester tester) {