[framework] partial removal of forced compositing from opacity (#106989)
diff --git a/packages/flutter/lib/src/rendering/proxy_box.dart b/packages/flutter/lib/src/rendering/proxy_box.dart
index 2af1c06..1d95a75 100644
--- a/packages/flutter/lib/src/rendering/proxy_box.dart
+++ b/packages/flutter/lib/src/rendering/proxy_box.dart
@@ -883,15 +883,7 @@
super(child);
@override
- bool get alwaysNeedsCompositing => child != null && (_alpha > 0);
-
- @override
- OffsetLayer updateCompositedLayer({required covariant OpacityLayer? oldLayer}) {
- assert(_alpha != 255);
- final OpacityLayer updatedLayer = oldLayer ?? OpacityLayer();
- updatedLayer.alpha = _alpha;
- return updatedLayer;
- }
+ bool get alwaysNeedsCompositing => child != null && (_alpha > 0 && _alpha < 255);
int _alpha;
@@ -949,19 +941,26 @@
@override
void paint(PaintingContext context, Offset offset) {
- if (child != null) {
- if (_alpha == 0) {
- // No need to keep the layer. We'll create a new one if necessary.
- layer = null;
- return;
- }
- assert(needsCompositing);
- layer = context.pushOpacity(offset, _alpha, super.paint, oldLayer: layer as OpacityLayer?);
- assert(() {
- layer!.debugCreator = debugCreator;
- return true;
- }());
+ if (child == null) {
+ return;
}
+ if (_alpha == 0) {
+ // No need to keep the layer. We'll create a new one if necessary.
+ layer = null;
+ return;
+ }
+ if (_alpha == 255) {
+ // No need to keep the layer. We'll create a new one if necessary.
+ layer = null;
+ return super.paint(context, offset);
+ }
+
+ assert(needsCompositing);
+ layer = context.pushOpacity(offset, _alpha, super.paint, oldLayer: layer as OpacityLayer?);
+ assert(() {
+ layer!.debugCreator = debugCreator;
+ return true;
+ }());
}
@override
diff --git a/packages/flutter/test/rendering/proxy_box_test.dart b/packages/flutter/test/rendering/proxy_box_test.dart
index 3077057..78c426e 100644
--- a/packages/flutter/test/rendering/proxy_box_test.dart
+++ b/packages/flutter/test/rendering/proxy_box_test.dart
@@ -240,12 +240,22 @@
expect(renderOpacity.needsCompositing, false);
});
- test('RenderOpacity does composite if it is opaque', () {
+ test('RenderOpacity does not composite if it is opaque', () {
final RenderOpacity renderOpacity = RenderOpacity(
child: RenderSizedBox(const Size(1.0, 1.0)), // size doesn't matter
);
layout(renderOpacity, phase: EnginePhase.composite);
+ expect(renderOpacity.needsCompositing, false);
+ });
+
+ test('RenderOpacity does composite if it is partially opaque', () {
+ final RenderOpacity renderOpacity = RenderOpacity(
+ opacity: 0.1,
+ child: RenderSizedBox(const Size(1.0, 1.0)), // size doesn't matter
+ );
+
+ layout(renderOpacity, phase: EnginePhase.composite);
expect(renderOpacity.needsCompositing, true);
});
diff --git a/packages/flutter/test/widgets/debug_test.dart b/packages/flutter/test/widgets/debug_test.dart
index ce1eabb..0ddcf3c 100644
--- a/packages/flutter/test/widgets/debug_test.dart
+++ b/packages/flutter/test/widgets/debug_test.dart
@@ -285,7 +285,7 @@
child: Placeholder(),
),
const Opacity(
- opacity: 1.0,
+ opacity: 0.9,
child: Placeholder(),
),
ImageFiltered(
