Add keys to ResourceImages.

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

@@ -2049,8 +2049,10 @@ class NetworkImage extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
+    ImageResource imageResource = imageCache.load(src, scale: scale);
     return new RawImageResource(
-      image: imageCache.load(src, scale: scale),
+      key: key == null ? new ObjectKey(imageResource) : null,
+      image: imageResource,
       width: width,
       height: height,
       color: color,
@@ -2171,8 +2173,10 @@ class AsyncImage extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
+    ImageResource imageResource = imageCache.loadProvider(provider);
     return new RawImageResource(
-      image: imageCache.loadProvider(provider),
+      key: key == null ? new ObjectKey(imageResource) : null,
+      image: imageResource,
       width: width,
       height: height,
       color: color,
@@ -2272,8 +2276,10 @@ class AssetImage extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
+    ImageResource imageResource = (bundle ?? DefaultAssetBundle.of(context)).loadImage(name);
     return new RawImageResource(
-      image: (bundle ?? DefaultAssetBundle.of(context)).loadImage(name),
+      key: key == null ? new ObjectKey(imageResource) : null,
+      image: imageResource,
       width: width,
       height: height,
       color: color,

packages/flutter/test/widget/image_test.dart

+// Copyright 2016 The Chromium 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 'dart:async';
+import 'dart:ui' as ui show Image;
+
+import 'package:mojo/core.dart' as core;
+import 'package:flutter_test/flutter_test.dart';
+import 'package:flutter/services.dart';
+import 'package:flutter/rendering.dart';
+import 'package:flutter/widgets.dart';
+import 'package:test/test.dart';
+
+void main() {
+  test('Verify NetworkImage sets an ObjectKey on its ImageResource if it doesn\'t have a key', () {
+    testWidgets((WidgetTester tester) {
+      final String testUrl = 'https://foo.bar/baz1.png';
+      tester.pumpWidget(
+        new NetworkImage(
+          scale: 1.0,
+          src: testUrl
+        )
+      );
+
+      ImageResource imageResource = imageCache.load(testUrl, scale: 1.0);
+      expect(tester.findElementByKey(new ObjectKey(imageResource)), isNotNull);
+    });
+  });
+
+  test('Verify NetworkImage doesn\'t set an ObjectKey on its ImageResource if it has a key', () {
+    testWidgets((WidgetTester tester) {
+      final String testUrl = 'https://foo.bar/baz2.png';
+      tester.pumpWidget(
+        new NetworkImage(
+          key: new GlobalKey(),
+          scale: 1.0,
+          src: testUrl
+        )
+      );
+
+      ImageResource imageResource = imageCache.load(testUrl, scale: 1.0);
+      expect(tester.findElementByKey(new ObjectKey(imageResource)), isNull);
+    });
+  });
+
+  test('Verify AsyncImage sets an ObjectKey on its ImageResource if it doesn\'t have a key', () {
+    testWidgets((WidgetTester tester) {
+      ImageProvider imageProvider = new TestImageProvider();
+      tester.pumpWidget(new AsyncImage(provider: imageProvider));
+
+      ImageResource imageResource = imageCache.loadProvider(imageProvider);
+      expect(tester.findElementByKey(new ObjectKey(imageResource)), isNotNull);
+    });
+  });
+
+  test('Verify AsyncImage doesn\'t set an ObjectKey on its ImageResource if it has a key', () {
+    testWidgets((WidgetTester tester) {
+      ImageProvider imageProvider = new TestImageProvider();
+      tester.pumpWidget(
+        new AsyncImage(
+          key: new GlobalKey(),
+          provider: imageProvider
+        )
+      );
+
+      ImageResource imageResource = imageCache.loadProvider(imageProvider);
+      expect(tester.findElementByKey(new ObjectKey(imageResource)), isNull);
+    });
+  });
+
+  test('Verify AssetImage sets an ObjectKey on its ImageResource if it doesn\'t have a key', () {
+    testWidgets((WidgetTester tester) {
+      final String name = 'foo';
+      final AssetBundle assetBundle = new TestAssetBundle();
+      tester.pumpWidget(
+        new AssetImage(
+          name: name,
+          bundle: assetBundle
+        )
+      );
+
+      ImageResource imageResource = assetBundle.loadImage(name);
+      expect(tester.findElementByKey(new ObjectKey(imageResource)), isNotNull);
+    });
+  });
+
+  test('Verify AssetImage doesn\'t set an ObjectKey on its ImageResource if it has a key', () {
+    testWidgets((WidgetTester tester) {
+      final String name = 'foo';
+      final AssetBundle assetBundle = new TestAssetBundle();
+      tester.pumpWidget(
+        new AssetImage(
+          key: new GlobalKey(),
+          name: name,
+          bundle: assetBundle
+        )
+      );
+
+      ImageResource imageResource = assetBundle.loadImage(name);
+      expect(tester.findElementByKey(new ObjectKey(imageResource)), isNull);
+    });
+  });
+
+  test('Verify AsyncImage resets its RenderImage when changing providers if it doesn\'t have a key', () {
+    testWidgets((WidgetTester tester) {
+      final GlobalKey key = new GlobalKey();
+      TestImageProvider imageProvider1 = new TestImageProvider();
+      tester.pumpWidget(
+        new Container(
+          key: key,
+          child: new AsyncImage(
+            provider: imageProvider1
+          )
+        )
+      );
+      RenderImage renderImage = key.currentContext.findRenderObject();
+      expect(renderImage.image, isNull);
+
+      // An exception will be thrown when we try to draw the image.  Catch it.
+      RenderingExceptionHandler originalRenderingExceptionHandler = debugRenderingExceptionHandler;
+      debugRenderingExceptionHandler = (_, __, ___, ____) => null;
+      imageProvider1.complete();
+      tester.pump();
+      tester.pump();
+      debugRenderingExceptionHandler = originalRenderingExceptionHandler;
+
+      renderImage = key.currentContext.findRenderObject();
+      expect(renderImage.image, isNotNull);
+
+      TestImageProvider imageProvider2 = new TestImageProvider();
+      tester.pumpWidget(
+        new Container(
+          key: key,
+          child: new AsyncImage(
+            provider: imageProvider2
+          )
+        )
+      );
+
+      renderImage = key.currentContext.findRenderObject();
+      expect(renderImage.image, isNull);
+
+    });
+  });
+
+  test('Verify AsyncImage doesn\'t reset its RenderImage when changing providers if it has a key', () {
+    testWidgets((WidgetTester tester) {
+      final GlobalKey key = new GlobalKey();
+      TestImageProvider imageProvider1 = new TestImageProvider();
+      tester.pumpWidget(
+        new AsyncImage(
+            key: key,
+            provider: imageProvider1
+        )
+      );
+      RenderImage renderImage = key.currentContext.findRenderObject();
+      expect(renderImage.image, isNull);
+
+      // An exception will be thrown when we try to draw the image.  Catch it.
+      RenderingExceptionHandler originalRenderingExceptionHandler = debugRenderingExceptionHandler;
+      debugRenderingExceptionHandler = (_, __, ___, ____) => null;
+      imageProvider1.complete();
+      tester.pump();
+      tester.pump();
+      debugRenderingExceptionHandler = originalRenderingExceptionHandler;
+
+      renderImage = key.currentContext.findRenderObject();
+      expect(renderImage.image, isNotNull);
+
+      TestImageProvider imageProvider2 = new TestImageProvider();
+      tester.pumpWidget(
+        new AsyncImage(
+          key: key,
+          provider: imageProvider2
+        )
+      );
+
+      renderImage = key.currentContext.findRenderObject();
+      expect(renderImage.image, isNotNull);
+    });
+  });
+
+}
+
+class TestImageProvider extends ImageProvider {
+  final Completer<ImageInfo> _completer = new Completer<ImageInfo>();
+
+  @override
+  Future<ImageInfo> loadImage() => _completer.future;
+
+  void complete() {
+    _completer.complete(new ImageInfo(image:new TestImage()));
+  }
+}
+
+class TestAssetBundle extends AssetBundle {
+  final ImageResource _imageResource = new ImageResource(new Completer<ImageInfo>().future);
+
+  @override
+  ImageResource loadImage(String key) => _imageResource;
+
+  @override
+  Future<String> loadString(String key) => new Completer<String>().future;
+
+  @override
+  Future<core.MojoDataPipeConsumer> load(String key) => new Completer<core.MojoDataPipeConsumer>().future;
+}
+
+class TestImage extends ui.Image {
+  @override
+  int get width => 100;
+
+  @override
+  int get height => 100;
+
+  @override
+  void dispose() {
+  }
+}