Revert "Enable taking screenshots of arbitrary RenderObjects from a running a… (#20637)" (#21395)

This reverts commit 3306fc10.

bin/internal/goldens.version

-da615501c1032cb803b2a5623b07d7f4834d9640
+1a999092d10a22bc700214b257cd4890c5800078

packages/flutter/lib/src/rendering/layer.dart

@@ -50,8 +50,6 @@ abstract class Layer extends AbstractNode with DiagnosticableTreeMixin {
   Layer _previousSibling;
 
   /// Removes this layer from its parent layer's child list.
-  ///
-  /// This has no effect if the layer's parent is already null.
   @mustCallSuper
   void remove() {
     parent?._removeChild(this);
@@ -590,11 +588,7 @@ class OffsetLayer extends ContainerLayer {
     assert(bounds != null);
     assert(pixelRatio != null);
     final ui.SceneBuilder builder = new ui.SceneBuilder();
-    final Matrix4 transform = new Matrix4.translationValues(
-      (-bounds.left  - offset.dx) * pixelRatio,
-      (-bounds.top - offset.dy) * pixelRatio,
-      0.0,
-    );
+    final Matrix4 transform = new Matrix4.translationValues(bounds.left - offset.dx, bounds.top - offset.dy, 0.0);
     transform.scale(pixelRatio, pixelRatio);
     builder.pushTransform(transform.storage);
     addToScene(builder, Offset.zero);

packages/flutter/lib/src/rendering/object.dart

@@ -60,13 +60,7 @@ typedef void PaintingContextCallback(PaintingContext context, Offset offset);
 /// New [PaintingContext] objects are created automatically when using
 /// [PaintingContext.repaintCompositedChild] and [pushLayer].
 class PaintingContext extends ClipContext {
-
-  /// Creates a painting context.
-  ///
-  /// Typically only called by [PaintingContext.repaintCompositedChild]
-  /// and [pushLayer].
-  @protected
-  PaintingContext(this._containerLayer, this.estimatedBounds)
+  PaintingContext._(this._containerLayer, this.estimatedBounds)
     : assert(_containerLayer != null),
       assert(estimatedBounds != null);
 
@@ -92,19 +86,8 @@ class PaintingContext extends ClipContext {
   ///  * [RenderObject.isRepaintBoundary], which determines if a [RenderObject]
   ///    has a composited layer.
   static void repaintCompositedChild(RenderObject child, { bool debugAlsoPaintedParent = false }) {
-    assert(child._needsPaint);
-    _repaintCompositedChild(
-      child,
-      debugAlsoPaintedParent: debugAlsoPaintedParent,
-    );
-  }
-
-  static void _repaintCompositedChild(
-    RenderObject child, {
-    bool debugAlsoPaintedParent = false,
-    PaintingContext childContext,
-  }) {
     assert(child.isRepaintBoundary);
+    assert(child._needsPaint);
     assert(() {
       // register the call for RepaintBoundary metrics
       child.debugRegisterRepaintBoundaryPaint(
@@ -124,32 +107,9 @@ class PaintingContext extends ClipContext {
       child._layer.debugCreator = child.debugCreator ?? child.runtimeType;
       return true;
     }());
-    childContext ??= new PaintingContext(child._layer, child.paintBounds);
+    final PaintingContext childContext = new PaintingContext._(child._layer, child.paintBounds);
     child._paintWithContext(childContext, Offset.zero);
-    childContext.stopRecordingIfNeeded();
-  }
-
-  /// In debug mode, repaint the given render object using a custom painting
-  /// context that can record the results of the painting operation in addition
-  /// to performing the regular paint of the child.
-  ///
-  /// See also:
-  ///
-  ///  * [repaintCompositedChild], for repainting a composited child without
-  ///    instrumentation.
-  static void debugInstrumentRepaintCompositedChild(
-    RenderObject child, {
-    bool debugAlsoPaintedParent = false,
-    @required PaintingContext customContext,
-  }) {
-    assert(() {
-      _repaintCompositedChild(
-        child,
-        debugAlsoPaintedParent: debugAlsoPaintedParent,
-        childContext: customContext,
-      );
-      return true;
-    }());
+    childContext._stopRecordingIfNeeded();
   }
 
   /// Paint a child [RenderObject].
@@ -165,7 +125,7 @@ class PaintingContext extends ClipContext {
     }());
 
     if (child.isRepaintBoundary) {
-      stopRecordingIfNeeded();
+      _stopRecordingIfNeeded();
       _compositeChild(child, offset);
     } else {
       child._paintWithContext(this, offset);
@@ -199,20 +159,10 @@ class PaintingContext extends ClipContext {
       }());
     }
     child._layer.offset = offset;
-    appendLayer(child._layer);
+    _appendLayer(child._layer);
   }
 
-  /// Adds a layer to the recording requiring that the recording is already
-  /// stopped.
-  ///
-  /// Do not call this function directly: call [addLayer] or [pushLayer]
-  /// instead. This function is called internally when all layers not
-  /// generated from the [canvas] are added.
-  ///
-  /// Subclasses that need to customize how layers are added should override
-  /// this method.
-  @protected
-  void appendLayer(Layer layer) {
+  void _appendLayer(Layer layer) {
     assert(!_isRecording);
     layer.remove();
     _containerLayer.append(layer);
@@ -260,19 +210,7 @@ class PaintingContext extends ClipContext {
     _containerLayer.append(_currentLayer);
   }
 
-  /// Stop recording to a canvas if recording has started.
-  ///
-  /// Do not call this function directly: functions in this class will call
-  /// this method as needed. This function is called internally to ensure that
-  /// recording is stopped before adding layers or finalizing the results of a
-  /// paint.
-  ///
-  /// Subclasses that need to customize how recording to a canvas is performed
-  /// should override this method to save the results of the custom canvas
-  /// recordings.
-  @protected
-  @mustCallSuper
-  void stopRecordingIfNeeded() {
+  void _stopRecordingIfNeeded() {
     if (!_isRecording)
       return;
     assert(() {
@@ -333,8 +271,8 @@ class PaintingContext extends ClipContext {
   ///  * [pushLayer], for adding a layer and using its canvas to paint with that
   ///    layer.
   void addLayer(Layer layer) {
-    stopRecordingIfNeeded();
-    appendLayer(layer);
+    _stopRecordingIfNeeded();
+    _appendLayer(layer);
   }
 
   /// Appends the given layer to the recording, and calls the `painter` callback
@@ -357,21 +295,15 @@ class PaintingContext extends ClipContext {
   /// See also:
   ///
   ///  * [addLayer], for pushing a leaf layer whose canvas is not used.
-  void pushLayer(ContainerLayer childLayer, PaintingContextCallback painter, Offset offset, { Rect childPaintBounds }) {
+  void pushLayer(Layer childLayer, PaintingContextCallback painter, Offset offset, { Rect childPaintBounds }) {
     assert(!childLayer.attached);
     assert(childLayer.parent == null);
     assert(painter != null);
-    stopRecordingIfNeeded();
-    appendLayer(childLayer);
-    final PaintingContext childContext = createChildContext(childLayer, childPaintBounds ?? estimatedBounds);
+    _stopRecordingIfNeeded();
+    _appendLayer(childLayer);
+    final PaintingContext childContext = new PaintingContext._(childLayer, childPaintBounds ?? estimatedBounds);
     painter(childContext, offset);
-    childContext.stopRecordingIfNeeded();
-  }
-
-  /// Creates a compatible painting context to paint onto [childLayer].
-  @protected
-  PaintingContext createChildContext(ContainerLayer childLayer, Rect bounds) {
-    return new PaintingContext(childLayer, bounds);
+    childContext._stopRecordingIfNeeded();
   }
 
   /// Clip further painting using a rectangle.
@@ -2104,6 +2036,7 @@ abstract class RenderObject extends AbstractNode with DiagnosticableTreeMixin im
   Rect get paintBounds;
 
   /// Override this method to paint debugging information.
+  @protected
   void debugPaint(PaintingContext context, Offset offset) { }
 
   /// Paint this render object into the given context at the given offset.

packages/flutter/test/foundation/service_extensions_test.dart

@@ -512,7 +512,7 @@ void main() {
 
     // If you add a service extension... TEST IT! :-)
     // ...then increment this number.
-    expect(binding.extensions.length, 38);
+    expect(binding.extensions.length, 37);
 
     expect(console, isEmpty);
     debugPrint = debugPrintThrottled;

packages/flutter/test/rendering/proxy_box_test.dart

@@ -185,43 +185,12 @@ void main() {
     image = await boundary.toImage();
     expect(image.width, equals(20));
     expect(image.height, equals(20));
-    ByteData data = await image.toByteData();
-
-    int getPixel(int x, int y) => data.getUint32((x + y * image.width) * 4);
-
+    final ByteData data = await image.toByteData();
     expect(data.lengthInBytes, equals(20 * 20 * 4));
     expect(data.elementSizeInBytes, equals(1));
-    expect(getPixel(0, 0), equals(0x00000080));
-    expect(getPixel(image.width - 1, 0 ), equals(0xffffffff));
-
-    final OffsetLayer layer = boundary.layer;
-
-    image = await layer.toImage(Offset.zero & const Size(20.0, 20.0));
-    expect(image.width, equals(20));
-    expect(image.height, equals(20));
-    data = await image.toByteData();
-    expect(getPixel(0, 0), equals(0x00000080));
-    expect(getPixel(image.width - 1, 0 ), equals(0xffffffff));
-
-    // non-zero offsets.
-    image = await layer.toImage(const Offset(-10.0, -10.0) & const Size(30.0, 30.0));
-    expect(image.width, equals(30));
-    expect(image.height, equals(30));
-    data = await image.toByteData();
-    expect(getPixel(0, 0), equals(0x00000000));
-    expect(getPixel(10, 10), equals(0x00000080));
-    expect(getPixel(image.width - 1, 0), equals(0x00000000));
-    expect(getPixel(image.width - 1, 10), equals(0xffffffff));
-
-    // offset combined with a custom pixel ratio.
-    image = await layer.toImage(const Offset(-10.0, -10.0) & const Size(30.0, 30.0), pixelRatio: 2.0);
-    expect(image.width, equals(60));
-    expect(image.height, equals(60));
-    data = await image.toByteData();
-    expect(getPixel(0, 0), equals(0x00000000));
-    expect(getPixel(20, 20), equals(0x00000080));
-    expect(getPixel(image.width - 1, 0), equals(0x00000000));
-    expect(getPixel(image.width - 1, 20), equals(0xffffffff));
+    const int stride = 20 * 4;
+    expect(data.getUint32(0), equals(0x00000080));
+    expect(data.getUint32(stride - 4), equals(0xffffffff));
   });
 
   test('RenderOpacity does not composite if it is transparent', () {

packages/flutter_test/lib/src/matchers.dart

@@ -251,12 +251,8 @@ Matcher isMethodCall(String name, {@required dynamic arguments}) {
 Matcher coversSameAreaAs(Path expectedPath, {@required Rect areaToCompare, int sampleSize = 20})
   => new _CoversSameAreaAs(expectedPath, areaToCompare: areaToCompare, sampleSize: sampleSize);
 
-/// Asserts that a [Finder], [Future<ui.Image>], or [ui.Image] matches the
-/// golden image file identified by [key].
-///
-/// For the case of a [Finder], the [Finder] must match exactly one widget and
-/// the rendered image of the first [RepaintBoundary] ancestor of the widget is
-/// treated as the image for the widget.
+/// Asserts that a [Finder] matches exactly one widget whose rendered image
+/// matches the golden image file identified by [key].
 ///
 /// [key] may be either a [Uri] or a [String] representation of a URI.
 ///
@@ -268,8 +264,6 @@ Matcher coversSameAreaAs(Path expectedPath, {@required Rect areaToCompare, int s
 ///
 /// ```dart
 /// await expectLater(find.text('Save'), matchesGoldenFile('save.png'));
-/// await expectLater(image, matchesGoldenFile('save.png'));
-/// await expectLater(imageFuture, matchesGoldenFile('save.png'));
 /// ```
 ///
 /// See also:
@@ -1502,17 +1496,6 @@ class _CoversSameAreaAs extends Matcher {
     description.add('covers expected area and only expected area');
 }
 
-Future<ui.Image> _captureImage(Element element) {
-  RenderObject renderObject = element.renderObject;
-  while (!renderObject.isRepaintBoundary) {
-    renderObject = renderObject.parent;
-    assert(renderObject != null);
-  }
-  assert(!renderObject.debugNeedsPaint);
-  final OffsetLayer layer = renderObject.layer;
-  return layer.toImage(renderObject.paintBounds);
-}
-
 class _MatchesGoldenFile extends AsyncMatcher {
   const _MatchesGoldenFile(this.key);
 
@@ -1521,22 +1504,23 @@ class _MatchesGoldenFile extends AsyncMatcher {
   final Uri key;
 
   @override
-  Future<String> matchAsync(dynamic item) async {
-    Future<ui.Image> imageFuture;
-    if (item is Future<ui.Image>) {
-      imageFuture = item;
-    } else if (item is ui.Image) {
-      imageFuture = new Future<ui.Image>.value(item);
-    } else {
-      final Finder finder = item;
-      final Iterable<Element> elements = finder.evaluate();
-      if (elements.isEmpty) {
-        return 'could not be rendered because no widget was found';
-      } else if (elements.length > 1) {
-        return 'matched too many widgets';
-      }
-      imageFuture = _captureImage(elements.single);
+  Future<String> matchAsync(covariant Finder finder) async {
+    final Iterable<Element> elements = finder.evaluate();
+    if (elements.isEmpty) {
+      return 'could not be rendered because no widget was found';
+    } else if (elements.length > 1) {
+      return 'matched too many widgets';
+    }
+    final Element element = elements.single;
+
+    RenderObject renderObject = element.renderObject;
+    while (!renderObject.isRepaintBoundary) {
+      renderObject = renderObject.parent;
+      assert(renderObject != null);
     }
+    assert(!renderObject.debugNeedsPaint);
+    final OffsetLayer layer = renderObject.layer;
+    final Future<ui.Image> imageFuture = layer.toImage(renderObject.paintBounds);
 
     final TestWidgetsFlutterBinding binding = TestWidgetsFlutterBinding.ensureInitialized();
     return binding.runAsync<String>(() async {