Image should handle InheritedWidget ancestor changes (#5656)

packages/flutter/lib/src/widgets/image.dart

@@ -193,6 +193,15 @@ class _ImageState extends State<Image> {
       _resolveImage();
   }
 
+  @override
+  void deactivate() {
+    // If this image is activated again then force _imageStream to be recreated,
+    // in case the InheritedWidget ancestors it depends on have changed.
+    _imageStream?.removeListener(_handleImageChanged);
+    _imageStream = null;
+    super.deactivate();
+  }
+
   @override
   void dependenciesChanged() {
     _resolveImage();
@@ -205,12 +214,6 @@ class _ImageState extends State<Image> {
     super.reassemble();
   }
 
-  @override
-  void dispose() {
-    _imageStream.removeListener(_handleImageChanged);
-    super.dispose();
-  }
-
   void _resolveImage() {
     final ImageStream oldImageStream = _imageStream;
     _imageStream = config.image.resolve(createLocalImageConfiguration(

packages/flutter/test/widget/image_test.dart

@@ -163,16 +163,146 @@ void main() {
     expect(renderImage.image, isNotNull);
   });
 
+  testWidgets('Verify ImageProvider configuration inheritance', (WidgetTester tester) async {
+    final GlobalKey mediaQueryKey1 = new GlobalKey(debugLabel: 'mediaQueryKey1');
+    final GlobalKey mediaQueryKey2 = new GlobalKey(debugLabel: 'mediaQueryKey2');
+    final GlobalKey imageKey = new GlobalKey(debugLabel: 'image');
+    final TestImageProvider imageProvider = new TestImageProvider();
+
+    // Of the two nested MediaQuery objects, the innermost one,
+    // mediaQuery2, should define the configuration of the imageProvider.
+    await tester.pumpWidget(
+      new MediaQuery(
+        key: mediaQueryKey1,
+        data: new MediaQueryData(
+          devicePixelRatio: 10.0,
+          padding: EdgeInsets.zero,
+        ),
+        child: new MediaQuery(
+          key: mediaQueryKey2,
+          data: new MediaQueryData(
+            devicePixelRatio: 5.0,
+            padding: EdgeInsets.zero,
+          ),
+          child: new Image(
+            key: imageKey,
+            image: imageProvider
+          ),
+        )
+      )
+    );
+
+    expect(imageProvider._configuration.devicePixelRatio, 5.0);
+
+    // This is the same widget hierarchy as before except that the
+    // two MediaQuery objects have exchanged places. The imageProvider
+    // should be resolved again, with the new innermost MediaQuery.
+    await tester.pumpWidget(
+      new MediaQuery(
+        key: mediaQueryKey2,
+        data: new MediaQueryData(
+          devicePixelRatio: 5.0,
+          padding: EdgeInsets.zero,
+        ),
+        child: new MediaQuery(
+          key: mediaQueryKey1,
+          data: new MediaQueryData(
+            devicePixelRatio: 10.0,
+            padding: EdgeInsets.zero,
+          ),
+          child: new Image(
+            key: imageKey,
+            image: imageProvider
+          ),
+        )
+      )
+    );
+
+    expect(imageProvider._configuration.devicePixelRatio, 10.0);
+  });
+
+  testWidgets('Verify ImageProvider configuration inheritance again', (WidgetTester tester) async {
+    final GlobalKey mediaQueryKey1 = new GlobalKey(debugLabel: 'mediaQueryKey1');
+    final GlobalKey mediaQueryKey2 = new GlobalKey(debugLabel: 'mediaQueryKey2');
+    final GlobalKey imageKey = new GlobalKey(debugLabel: 'image');
+    final TestImageProvider imageProvider = new TestImageProvider();
+
+    // This is just a variation on the previous test.  In this version the location
+    // of the Image changes and the MediaQuery widgets do not.
+    await tester.pumpWidget(
+      new Row(
+        children: <Widget> [
+          new MediaQuery(
+            key: mediaQueryKey2,
+            data: new MediaQueryData(
+              devicePixelRatio: 5.0,
+              padding: EdgeInsets.zero,
+            ),
+            child: new Image(
+              key: imageKey,
+              image: imageProvider
+            )
+          ),
+          new MediaQuery(
+            key: mediaQueryKey1,
+            data: new MediaQueryData(
+              devicePixelRatio: 10.0,
+              padding: EdgeInsets.zero,
+            ),
+            child: new Container(width: 100.0)
+          )
+        ]
+      )
+    );
+
+    expect(imageProvider._configuration.devicePixelRatio, 5.0);
+
+    await tester.pumpWidget(
+      new Row(
+        children: <Widget> [
+          new MediaQuery(
+            key: mediaQueryKey2,
+            data: new MediaQueryData(
+              devicePixelRatio: 5.0,
+              padding: EdgeInsets.zero,
+            ),
+            child: new Container(width: 100.0)
+          ),
+          new MediaQuery(
+            key: mediaQueryKey1,
+            data: new MediaQueryData(
+              devicePixelRatio: 10.0,
+              padding: EdgeInsets.zero,
+            ),
+            child: new Image(
+              key: imageKey,
+              image: imageProvider
+            )
+          )
+        ]
+      )
+    );
+
+    expect(imageProvider._configuration.devicePixelRatio, 10.0);
+  });
+
 }
 
 class TestImageProvider extends ImageProvider<TestImageProvider> {
   final Completer<ImageInfo> _completer = new Completer<ImageInfo>();
+  ImageConfiguration _configuration;
 
   @override
   Future<TestImageProvider> obtainKey(ImageConfiguration configuration) {
     return new SynchronousFuture<TestImageProvider>(this);
   }
 
+  @override
+  ImageStream resolve(ImageConfiguration configuration) {
+    _configuration = configuration;
+    return super.resolve(configuration);
+  }
+
   @override
   ImageStreamCompleter load(TestImageProvider key) => new OneFrameImageStreamCompleter(_completer.future);