OverlayPortal (#105335)

`OverlayPortal`

Author: LongCatIsLooong

examples/api/lib/widgets/overlay/overlay_portal.0.dart

@@ -0,0 +1,59 @@
+// Copyright 2014 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flutter code sample for OverlayPortal
+
+import 'package:flutter/material.dart';
+
+void main() => runApp(const MyApp());
+
+class MyApp extends StatelessWidget {
+  const MyApp({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return MaterialApp(
+      title: 'Flutter Code Sample',
+      home: Scaffold(
+        appBar: AppBar(title: const Text('OverlayPortal Example')),
+        body: const Center(child: ClickableTooltipWidget()),
+      ),
+    );
+  }
+}
+
+class ClickableTooltipWidget extends StatefulWidget {
+  const ClickableTooltipWidget({super.key});
+
+  @override
+  State<StatefulWidget> createState() => ClickableTooltipWidgetState();
+}
+
+class ClickableTooltipWidgetState extends State<ClickableTooltipWidget> {
+  final OverlayPortalController _tooltipController = OverlayPortalController();
+
+  @override
+  Widget build(BuildContext context) {
+    return TextButton(
+      onPressed: _tooltipController.toggle,
+      child: DefaultTextStyle(
+        style: DefaultTextStyle.of(context).style.copyWith(fontSize: 50),
+        child: OverlayPortal(
+          controller: _tooltipController,
+          overlayChildBuilder: (BuildContext context) {
+            return const Positioned(
+              right: 50,
+              bottom: 50,
+              child: ColoredBox(
+                color: Colors.amberAccent,
+                child: Text('tooltip'),
+              ),
+            );
+          },
+          child: const Text('Press to show/hide tooltip'),
+        ),
+      ),
+    );
+  }
+}

examples/api/test/widgets/overlay/overlay_portal.0_test.dart

@@ -0,0 +1,44 @@
+// Copyright 2014 The Flutter 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 'package:flutter/rendering.dart';
+import 'package:flutter_api_samples/widgets/overlay/overlay_portal.0.dart' as example;
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  const String tooltipText = 'tooltip';
+  testWidgets('Tooltip is shown on press', (WidgetTester tester) async {
+    await tester.pumpWidget(const example.MyApp());
+    expect(find.text(tooltipText), findsNothing);
+
+    await tester.tap(find.byType(example.ClickableTooltipWidget));
+    await tester.pump();
+    expect(find.text(tooltipText), findsOneWidget);
+
+    await tester.tap(find.byType(example.ClickableTooltipWidget));
+    await tester.pump();
+    expect(find.text(tooltipText), findsNothing);
+  });
+
+  testWidgets('Tooltip is shown at the right location', (WidgetTester tester) async {
+    await tester.pumpWidget(const example.MyApp());
+    await tester.tap(find.byType(example.ClickableTooltipWidget));
+    await tester.pump();
+
+    final Size canvasSize = tester.getSize(find.byType(example.MyApp));
+    expect(
+      tester.getBottomRight(find.text(tooltipText)),
+      canvasSize - const Size(50, 50),
+    );
+  });
+
+  testWidgets('Tooltip is shown with the right font size', (WidgetTester tester) async {
+    await tester.pumpWidget(const example.MyApp());
+    await tester.tap(find.byType(example.ClickableTooltipWidget));
+    await tester.pump();
+
+    final TextSpan textSpan = tester.renderObject<RenderParagraph>(find.text(tooltipText)).text as TextSpan;
+    expect(textSpan.style?.fontSize, 50);
+  });
+}

packages/flutter/lib/src/material/material.dart

@@ -641,7 +641,7 @@ class _RenderInkFeatures extends RenderProxyBox implements MaterialInkController
   }
 
   void _didChangeLayout() {
-    if (_inkFeatures != null && _inkFeatures!.isNotEmpty) {
+    if (_inkFeatures?.isNotEmpty ?? false) {
       markNeedsPaint();
     }
   }
@@ -651,16 +651,18 @@ class _RenderInkFeatures extends RenderProxyBox implements MaterialInkController
 
   @override
   void paint(PaintingContext context, Offset offset) {
-    if (_inkFeatures != null && _inkFeatures!.isNotEmpty) {
+    final List<InkFeature>? inkFeatures = _inkFeatures;
+    if (inkFeatures != null && inkFeatures.isNotEmpty) {
       final Canvas canvas = context.canvas;
       canvas.save();
       canvas.translate(offset.dx, offset.dy);
       canvas.clipRect(Offset.zero & size);
-      for (final InkFeature inkFeature in _inkFeatures!) {
+      for (final InkFeature inkFeature in inkFeatures) {
         inkFeature._paint(canvas);
       }
       canvas.restore();
     }
+    assert(inkFeatures == _inkFeatures);
     super.paint(context, offset);
   }
 }
@@ -740,32 +742,71 @@ abstract class InkFeature {
     onRemoved?.call();
   }
 
+  // Returns the paint transform that allows `fromRenderObject` to perform paint
+  // in `toRenderObject`'s coordinate space.
+  //
+  // Returns null if either `fromRenderObject` or `toRenderObject` is not in the
+  // same render tree, or either of them is in an offscreen subtree (see
+  // RenderObject.paintsChild).
+  static Matrix4? _getPaintTransform(
+    RenderObject fromRenderObject,
+    RenderObject toRenderObject,
+  ) {
+    // The paths to fromRenderObject and toRenderObject's common ancestor.
+    final List<RenderObject> fromPath = <RenderObject>[fromRenderObject];
+    final List<RenderObject> toPath = <RenderObject>[toRenderObject];
+
+    RenderObject from = fromRenderObject;
+    RenderObject to = toRenderObject;
+
+    while (!identical(from, to)) {
+      final int fromDepth = from.depth;
+      final int toDepth = to.depth;
+
+      if (fromDepth >= toDepth) {
+        final AbstractNode? fromParent = from.parent;
+        // Return early if the 2 render objects are not in the same render tree,
+        // or either of them is offscreen and thus won't get painted.
+        if (fromParent is! RenderObject || !fromParent.paintsChild(from)) {
+          return null;
+        }
+        fromPath.add(fromParent);
+        from = fromParent;
+      }
+
+      if (fromDepth <= toDepth) {
+        final AbstractNode? toParent = to.parent;
+        if (toParent is! RenderObject || !toParent.paintsChild(to)) {
+          return null;
+        }
+        toPath.add(toParent);
+        to = toParent;
+      }
+    }
+    assert(identical(from, to));
+
+    final Matrix4 transform = Matrix4.identity();
+    final Matrix4 inverseTransform = Matrix4.identity();
+
+    for (int index = toPath.length - 1; index > 0; index -= 1) {
+      toPath[index].applyPaintTransform(toPath[index - 1], transform);
+    }
+    for (int index = fromPath.length - 1; index > 0; index -= 1) {
+      fromPath[index].applyPaintTransform(fromPath[index - 1], inverseTransform);
+    }
+
+    final double det = inverseTransform.invert();
+    return det != 0 ? (inverseTransform..multiply(transform)) : null;
+  }
+
   void _paint(Canvas canvas) {
     assert(referenceBox.attached);
     assert(!_debugDisposed);
-    // find the chain of renderers from us to the feature's referenceBox
-    final List<RenderObject> descendants = <RenderObject>[referenceBox];
-    RenderObject node = referenceBox;
-    while (node != _controller) {
-      final RenderObject childNode = node;
-      node = node.parent! as RenderObject;
-      if (!node.paintsChild(childNode)) {
-        // Some node between the reference box and this would skip painting on
-        // the reference box, so bail out early and avoid unnecessary painting.
-        // Some cases where this can happen are the reference box being
-        // offstage, in a fully transparent opacity node, or in a keep alive
-        // bucket.
-        return;
-      }
-      descendants.add(node);
-    }
     // determine the transform that gets our coordinate system to be like theirs
-    final Matrix4 transform = Matrix4.identity();
-    assert(descendants.length >= 2);
-    for (int index = descendants.length - 1; index > 0; index -= 1) {
-      descendants[index].applyPaintTransform(descendants[index - 1], transform);
+    final Matrix4? transform = _getPaintTransform(_controller, referenceBox);
+    if (transform != null) {
+      paintFeature(canvas, transform);
     }
-    paintFeature(canvas, transform);
   }
 
   /// Override this method to paint the ink feature.

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

@@ -1486,7 +1486,6 @@ abstract class RenderObject extends AbstractNode with DiagnosticableTreeMixin im
   /// in other cases will lead to an inconsistent tree and probably cause crashes.
   @override
   void adoptChild(RenderObject child) {
-    assert(_debugCanPerformMutations);
     setupParentData(child);
     markNeedsLayout();
     markNeedsCompositingBitsUpdate();
@@ -1500,7 +1499,6 @@ abstract class RenderObject extends AbstractNode with DiagnosticableTreeMixin im
   /// in other cases will lead to an inconsistent tree and probably cause crashes.
   @override
   void dropChild(RenderObject child) {
-    assert(_debugCanPerformMutations);
     assert(child.parentData != null);
     child._cleanRelayoutBoundary();
     child.parentData!.detach();
@@ -1643,7 +1641,7 @@ abstract class RenderObject extends AbstractNode with DiagnosticableTreeMixin im
         }
 
         if (!activeLayoutRoot._debugMutationsLocked) {
-          final AbstractNode? p = activeLayoutRoot.parent;
+          final AbstractNode? p = activeLayoutRoot.debugLayoutParent;
           activeLayoutRoot = p is RenderObject ? p : null;
         } else {
           // activeLayoutRoot found.
@@ -1722,6 +1720,29 @@ abstract class RenderObject extends AbstractNode with DiagnosticableTreeMixin im
     return result;
   }
 
+  /// The [RenderObject] that's expected to call [layout] on this [RenderObject]
+  /// in its [performLayout] implementation.
+  ///
+  /// This method is used to implement an assert that ensures the render subtree
+  /// actively performing layout can not get accidently mutated. It's only
+  /// implemented in debug mode and always returns null in release mode.
+  ///
+  /// The default implementation returns [parent] and overriding is rarely
+  /// needed. A [RenderObject] subclass that expects its
+  /// [RenderObject.performLayout] to be called from a different [RenderObject]
+  /// that's not its [parent] should override this property to return the actual
+  /// layout parent.
+  @protected
+  RenderObject? get debugLayoutParent {
+    RenderObject? layoutParent;
+    assert(() {
+      final AbstractNode? parent = this.parent;
+      layoutParent = parent is RenderObject? ? parent : null;
+      return true;
+    }());
+    return layoutParent;
+  }
+
   @override
   PipelineOwner? get owner => super.owner as PipelineOwner?;
 
@@ -3636,17 +3657,13 @@ mixin RenderObjectWithChildMixin<ChildType extends RenderObject> on RenderObject
   @override
   void attach(PipelineOwner owner) {
     super.attach(owner);
-    if (_child != null) {
-      _child!.attach(owner);
-    }
+    _child?.attach(owner);
   }
 
   @override
   void detach() {
     super.detach();
-    if (_child != null) {
-      _child!.detach();
-    }
+    _child?.detach();
   }
 
   @override

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

@@ -4701,6 +4701,7 @@ abstract class Element extends DiagnosticableTree implements BuildContext {
       performRebuild();
     } finally {
       assert(() {
+        owner!._debugElementWasRebuilt(this);
         assert(owner!._debugCurrentBuildTarget == this);
         owner!._debugCurrentBuildTarget = debugPreviousBuildTarget;
         return true;