Exclude Tooltip's overlay child from SelectableRegion (#130181)

Fixes flutter/flutter#129969 by making tooltip text unselectable (for now). 
Also fixes some other issues uncovered when I was writing the tests.

Currently `getTransformTo` only works on ancestors. I'll try to add a new method that computes the transform from 2 arbitrary render objects in the same render tree in a follow-up PR and make `Selectable` use that method instead.

Author: LongCatIsLooong

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

@@ -103,13 +103,7 @@ class SelectionArea extends StatefulWidget {
 }
 
 class _SelectionAreaState extends State<SelectionArea> {
-  FocusNode get _effectiveFocusNode {
-    if (widget.focusNode != null) {
-      return widget.focusNode!;
-    }
-    _internalNode ??= FocusNode();
-    return _internalNode!;
-  }
+  FocusNode get _effectiveFocusNode => widget.focusNode ?? (_internalNode ??= FocusNode());
   FocusNode? _internalNode;
 
   @override
@@ -121,20 +115,12 @@ class _SelectionAreaState extends State<SelectionArea> {
   @override
   Widget build(BuildContext context) {
     assert(debugCheckHasMaterialLocalizations(context));
-    TextSelectionControls? controls = widget.selectionControls;
-    switch (Theme.of(context).platform) {
-      case TargetPlatform.android:
-      case TargetPlatform.fuchsia:
-        controls ??= materialTextSelectionHandleControls;
-      case TargetPlatform.iOS:
-        controls ??= cupertinoTextSelectionHandleControls;
-      case TargetPlatform.linux:
-      case TargetPlatform.windows:
-        controls ??= desktopTextSelectionHandleControls;
-      case TargetPlatform.macOS:
-        controls ??= cupertinoDesktopTextSelectionHandleControls;
-    }
-
+    final TextSelectionControls controls = widget.selectionControls ?? switch (Theme.of(context).platform) {
+      TargetPlatform.android || TargetPlatform.fuchsia => materialTextSelectionHandleControls,
+      TargetPlatform.linux || TargetPlatform.windows   => desktopTextSelectionHandleControls,
+      TargetPlatform.iOS                               => cupertinoTextSelectionHandleControls,
+      TargetPlatform.macOS                             => cupertinoDesktopTextSelectionHandleControls,
+    };
     return SelectableRegion(
       selectionControls: controls,
       focusNode: _effectiveFocusNode,

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

@@ -482,13 +482,16 @@ class TooltipState extends State<Tooltip> with SingleTickerProviderStateMixin {
   void _scheduleDismissTooltip({ required Duration withDelay }) {
     assert(mounted);
     assert(
-      !(_timer?.isActive ?? false) || _controller.status != AnimationStatus.reverse,
+      !(_timer?.isActive ?? false) || _backingController?.status != AnimationStatus.reverse,
       'timer must not be active when the tooltip is fading out',
     );
 
     _timer?.cancel();
     _timer = null;
-    switch (_controller.status) {
+    // Use _backingController instead of _controller to prevent the lazy getter
+    // from instaniating an AnimationController unnecessarily.
+    switch (_backingController?.status) {
+      case null:
       case AnimationStatus.reverse:
       case AnimationStatus.dismissed:
         break;
@@ -740,7 +743,7 @@ class TooltipState extends State<Tooltip> with SingleTickerProviderStateMixin {
     };
 
     final TooltipThemeData tooltipTheme = _tooltipTheme;
-    return _TooltipOverlay(
+    final _TooltipOverlay overlayChild = _TooltipOverlay(
       richMessage: widget.richMessage ?? TextSpan(text: widget.message),
       height: widget.height ?? tooltipTheme.height ?? _getDefaultTooltipHeight(),
       padding: widget.padding ?? tooltipTheme.padding ?? _getDefaultPadding(),
@@ -755,13 +758,23 @@ class TooltipState extends State<Tooltip> with SingleTickerProviderStateMixin {
       verticalOffset: widget.verticalOffset ?? tooltipTheme.verticalOffset ?? _defaultVerticalOffset,
       preferBelow: widget.preferBelow ?? tooltipTheme.preferBelow ?? _defaultPreferBelow,
     );
+
+    return SelectionContainer.maybeOf(context) == null
+      ? overlayChild
+      : SelectionContainer.disabled(child: overlayChild);
   }
 
   @override
   void dispose() {
     GestureBinding.instance.pointerRouter.removeGlobalRoute(_handleGlobalPointerEvent);
     Tooltip._openedTooltips.remove(this);
+    // _longPressRecognizer.dispose() and _tapRecognizer.dispose() may call
+    // their registered onCancel callbacks if there's a gesture in progress.
+    // Remove the onCancel callbacks to prevent the registered callbacks from
+    // triggering unnecessary side effects (such as animations).
+    _longPressRecognizer?.onLongPressCancel = null;
     _longPressRecognizer?.dispose();
+    _tapRecognizer?.onTapCancel = null;
     _tapRecognizer?.dispose();
     _timer?.cancel();
     _backingController?.dispose();

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

@@ -1569,6 +1569,7 @@ class _OverlayPortalState extends State<OverlayPortal> {
 
   @override
   void dispose() {
+    assert(widget.controller._attachTarget == this);
     widget.controller._attachTarget = null;
     _locationCache?._debugMarkLocationInvalid();
     _locationCache = null;

packages/flutter/test/material/tooltip_test.dart

@@ -2278,6 +2278,97 @@ void main() {
     await tester.pump(const Duration(seconds: 1));
     expect(element.dirty, isFalse);
   });
+
+  testWidgets('Tooltip does not initialize animation controller in dispose process', (WidgetTester tester) async {
+    await tester.pumpWidget(
+      const MaterialApp(
+        home: Center(
+          child: Tooltip(
+            message: tooltipText,
+            waitDuration: Duration(seconds: 1),
+            triggerMode: TooltipTriggerMode.longPress,
+            child: SizedBox.square(dimension: 50),
+          ),
+        ),
+      ),
+    );
+
+    await tester.startGesture(tester.getCenter(find.byType(Tooltip)));
+    await tester.pumpWidget(const SizedBox());
+    expect(tester.takeException(), isNull);
+  });
+
+  testWidgets('Tooltip does not crash when showing the tooltip but the OverlayPortal is unmounted, during dispose', (WidgetTester tester) async {
+    await tester.pumpWidget(
+      const MaterialApp(
+        home: SelectionArea(
+          child: Center(
+            child: Tooltip(
+              message: tooltipText,
+              waitDuration: Duration(seconds: 1),
+              triggerMode: TooltipTriggerMode.longPress,
+              child: SizedBox.square(dimension: 50),
+            ),
+          ),
+        ),
+      ),
+    );
+
+    final TooltipState tooltipState = tester.state(find.byType(Tooltip));
+    await tester.startGesture(tester.getCenter(find.byType(Tooltip)));
+    tooltipState.ensureTooltipVisible();
+    await tester.pumpWidget(const SizedBox());
+    expect(tester.takeException(), isNull);
+  });
+
+  testWidgets('Tooltip is not selectable', (WidgetTester tester) async {
+    const String tooltipText = 'AAAAAAAAAAAAAAAAAAAAAAA';
+    String? selectedText;
+    await tester.pumpWidget(
+      MaterialApp(
+        home: SelectionArea(
+          onSelectionChanged: (SelectedContent? content) { selectedText = content?.plainText; },
+          child: const Center(
+            child: Column(
+              children: <Widget>[
+                Text('Select Me'),
+                Tooltip(
+                  message: tooltipText,
+                  waitDuration: Duration(seconds: 1),
+                  triggerMode: TooltipTriggerMode.longPress,
+                  child: SizedBox.square(dimension: 50),
+                ),
+              ],
+            ),
+          ),
+        ),
+      ),
+    );
+
+    final TooltipState tooltipState = tester.state(find.byType(Tooltip));
+
+    final Rect textRect = tester.getRect(find.text('Select Me'));
+    final TestGesture gesture = await tester.startGesture(Alignment.centerLeft.alongSize(textRect.size) + textRect.topLeft);
+    // Drag from centerLeft to centerRight to select the text.
+    await tester.pump(const Duration(seconds: 1));
+    await gesture.moveTo(Alignment.centerRight.alongSize(textRect.size) + textRect.topLeft);
+    await tester.pump();
+
+    tooltipState.ensureTooltipVisible();
+    await tester.pump();
+    // Make sure the tooltip becomes visible.
+    expect(find.text(tooltipText), findsOneWidget);
+    assert(selectedText != null);
+
+    final Rect tooltipTextRect = tester.getRect(find.text(tooltipText));
+    // Now drag from centerLeft to centerRight to select the tooltip text.
+    await gesture.moveTo(Alignment.centerLeft.alongSize(tooltipTextRect.size) + tooltipTextRect.topLeft);
+    await tester.pump();
+    await gesture.moveTo(Alignment.centerRight.alongSize(tooltipTextRect.size) + tooltipTextRect.topLeft);
+    await tester.pump();
+
+    expect(selectedText, isNot(contains('A')));
+  });
 }
 
 Future<void> setWidgetForTooltipMode(