Stop using SelectionChangedCause internally to show the text selection toolbar (#27534)

packages/flutter/lib/src/cupertino/text_field.dart

@@ -456,15 +456,18 @@ class _CupertinoTextFieldState extends State<CupertinoTextField> with AutomaticK
   }
 
   void _handleForcePressStarted(ForcePressDetails details) {
-    // The cause is not keyboard press but we would still like to just
-    // highlight the word without showing any handles or toolbar.
-    _renderEditable.selectWordsInRange(from: details.globalPosition, cause: SelectionChangedCause.keyboard);
+    _renderEditable.selectWordsInRange(
+      from: details.globalPosition,
+      cause: SelectionChangedCause.forcePress,
+    );
   }
 
   void _handleForcePressEnded(ForcePressDetails details) {
-    // The cause is not technically double tap, but we would still like to show
-    // the toolbar and handles.
-    _renderEditable.selectWordsInRange(from: details.globalPosition, cause: SelectionChangedCause.doubleTap);
+    _renderEditable.selectWordsInRange(
+      from: details.globalPosition,
+      cause: SelectionChangedCause.forcePress,
+    );
+    _editableTextKey.currentState.showToolbar();
   }
 
   void _handleSingleTapUp(TapUpDetails details) {
@@ -474,10 +477,12 @@ class _CupertinoTextFieldState extends State<CupertinoTextField> with AutomaticK
 
   void _handleSingleLongTapDown() {
     _renderEditable.selectPosition(cause: SelectionChangedCause.longPress);
+    _editableTextKey.currentState.showToolbar();
   }
 
   void _handleDoubleTapDown(TapDownDetails details) {
-    _renderEditable.selectWord(cause: SelectionChangedCause.doubleTap);
+    _renderEditable.selectWord(cause: SelectionChangedCause.tap);
+    _editableTextKey.currentState.showToolbar();
   }
 
   @override

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

@@ -582,11 +582,6 @@ class _TextFieldState extends State<TextField> with AutomaticKeepAliveClientMixi
     _editableTextKey.currentState?.requestKeyboard();
   }
 
-  void _handleSelectionChanged(TextSelection selection, SelectionChangedCause cause) {
-    if (cause == SelectionChangedCause.longPress)
-      Feedback.forLongPress(context);
-  }
-
   InteractiveInkFeature _createInkFeature(TapDownDetails details) {
     final MaterialInkController inkController = Material.of(context);
     final ThemeData themeData = Theme.of(context);
@@ -630,9 +625,11 @@ class _TextFieldState extends State<TextField> with AutomaticKeepAliveClientMixi
 
   void _handleForcePressStarted(ForcePressDetails details) {
     if (widget.selectionEnabled) {
-      // The cause is not technically double tap, but we would like to show
-      // the toolbar.
-      _renderEditable.selectWordsInRange(from: details.globalPosition, cause: SelectionChangedCause.doubleTap);
+      _renderEditable.selectWordsInRange(
+        from: details.globalPosition,
+        cause: SelectionChangedCause.forcePress,
+      );
+      _editableTextKey.currentState.showToolbar();
     }
   }
 
@@ -667,14 +664,19 @@ class _TextFieldState extends State<TextField> with AutomaticKeepAliveClientMixi
         case TargetPlatform.android:
         case TargetPlatform.fuchsia:
           _renderEditable.selectWord(cause: SelectionChangedCause.longPress);
+          Feedback.forLongPress(context);
           break;
       }
+      _editableTextKey.currentState.showToolbar();
     }
     _confirmCurrentSplash();
   }
 
   void _handleDoubleTapDown(TapDownDetails details) {
+    if (widget.selectionEnabled) {
       _renderEditable.selectWord(cause: SelectionChangedCause.doubleTap);
+      _editableTextKey.currentState.showToolbar();
+    }
   }
 
   void _startSplash(TapDownDetails details) {
@@ -784,7 +786,6 @@ class _TextFieldState extends State<TextField> with AutomaticKeepAliveClientMixi
         onChanged: widget.onChanged,
         onEditingComplete: widget.onEditingComplete,
         onSubmitted: widget.onSubmitted,
-        onSelectionChanged: _handleSelectionChanged,
         inputFormatters: formatters,
         rendererIgnoresPointer: true,
         cursorWidth: widget.cursorWidth,

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

@@ -45,6 +45,10 @@ enum SelectionChangedCause {
   /// location of the cursor) to change.
   longPress,
 
+  /// The user force-pressed the text and that caused the selection (or the
+  /// location of the cursor) to change.
+  forcePress,
+
   /// The user used the keyboard to change the selection or the location of the
   /// cursor.
   ///
@@ -737,12 +741,12 @@ class RenderEditable extends RenderBox {
     markNeedsLayout();
   }
 
-  ///{@template flutter.rendering.editable.paintCursorOnTop}
+  /// {@template flutter.rendering.editable.paintCursorOnTop}
   /// If the cursor should be painted on top of the text or underneath it.
   ///
   /// By default, the cursor should be painted on top for iOS platforms and
   /// underneath for Android platforms.
-  /// {@end template}
+  /// {@endtemplate}
   bool get paintCursorAboveText => _paintCursorOnTop;
   bool _paintCursorOnTop;
   set paintCursorAboveText(bool value) {
@@ -759,7 +763,7 @@ class RenderEditable extends RenderBox {
   /// (-[cursorWidth] * 0.5, 0.0) on iOS platforms and (0, 0) on Android
   /// platforms. The origin from where the offset is applied to is the arbitrary
   /// location where the cursor ends up being rendered from by default.
-  /// {@end template}
+  /// {@endtemplate}
   Offset get cursorOffset => _cursorOffset;
   Offset _cursorOffset;
   set cursorOffset(Offset value) {
@@ -1233,6 +1237,15 @@ class RenderEditable extends RenderBox {
   }
 
   /// Move selection to the location of the last tap down.
+  ///
+  /// {@template flutter.rendering.editable.select}
+  /// This method is mainly used to translate user inputs in global positions
+  /// into a [TextSelection]. When used in conjunction with a [EditableText],
+  /// the selection change is fed back into [TextEditingController.selection].
+  ///
+  /// If you have a [TextEditingController], it's generally easier to
+  /// programmatically manipulate its `value` or `selection` directly.
+  /// {@endtemplate}
   void selectPosition({@required SelectionChangedCause cause}) {
     assert(cause != null);
     _layoutText(constraints.maxWidth);
@@ -1244,6 +1257,8 @@ class RenderEditable extends RenderBox {
   }
 
   /// Select a word around the location of the last tap down.
+  ///
+  /// {@macro flutter.rendering.editable.select}
   void selectWord({@required SelectionChangedCause cause}) {
     selectWordsInRange(from: _lastTapDownPosition, cause: cause);
   }
@@ -1252,6 +1267,8 @@ class RenderEditable extends RenderBox {
   ///
   /// The first and last endpoints of the selection will always be at the
   /// beginning and end of a word respectively.
+  ///
+  /// {@macro flutter.rendering.editable.select}
   void selectWordsInRange({@required Offset from, Offset to, @required SelectionChangedCause cause}) {
     assert(cause != null);
     _layoutText(constraints.maxWidth);
@@ -1272,6 +1289,8 @@ class RenderEditable extends RenderBox {
   }
 
   /// Move the selection to the beginning or end of a word.
+  ///
+  /// {@macro flutter.rendering.editable.select}
   void selectWordEdge({@required SelectionChangedCause cause}) {
     assert(cause != null);
     _layoutText(constraints.maxWidth);

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

@@ -745,7 +745,7 @@ class EditableTextState extends State<EditableText> with AutomaticKeepAliveClien
       renderEditable.setFloatingCursor(FloatingCursorDragState.End, finalPosition, _lastTextPosition);
       if (_lastTextPosition.offset != renderEditable.selection.baseOffset)
         // The cause is technically the force cursor, but the cause is listed as tap as the desired functionality is the same.
-        _handleSelectionChanged(TextSelection.collapsed(offset: _lastTextPosition.offset), renderEditable, SelectionChangedCause.tap);
+        _handleSelectionChanged(TextSelection.collapsed(offset: _lastTextPosition.offset), renderEditable, SelectionChangedCause.forcePress);
       _startCaretRect = null;
       _lastTextPosition = null;
       _pointOffsetOrigin = null;
@@ -923,8 +923,6 @@ class EditableTextState extends State<EditableText> with AutomaticKeepAliveClien
       final bool longPress = cause == SelectionChangedCause.longPress;
       if (cause != SelectionChangedCause.keyboard && (_value.text.isNotEmpty || longPress))
         _selectionOverlay.showHandles();
-      if (longPress || cause == SelectionChangedCause.doubleTap)
-        _selectionOverlay.showToolbar();
       if (widget.onSelectionChanged != null)
         widget.onSelectionChanged(selection, cause);
     }
@@ -1150,6 +1148,18 @@ class EditableTextState extends State<EditableText> with AutomaticKeepAliveClien
     _scrollController.jumpTo(_getScrollOffsetForCaret(renderEditable.getLocalRectForCaret(position)));
   }
 
+  /// Shows the selection toolbar at the location of the current cursor.
+  ///
+  /// Returns `false` if a toolbar couldn't be shown such as when no text
+  /// selection currently exists.
+  bool showToolbar() {
+    if (_selectionOverlay == null)
+      return false;
+
+    _selectionOverlay.showToolbar();
+    return true;
+  }
+
   @override
   void hideToolbar() {
     _selectionOverlay?.hide();

packages/flutter/test/widgets/editable_text_cursor_test.dart

@@ -71,6 +71,7 @@ void main() {
     // Long-press to bring up the text editing controls.
     final Finder textFinder = find.byKey(editableTextKey);
     await tester.longPress(textFinder);
+    tester.state<EditableTextState>(textFinder).showToolbar();
     await tester.pump();
     await tester.pump(const Duration(milliseconds: 500));
     await tester.pump(const Duration(milliseconds: 500));
@@ -125,6 +126,7 @@ void main() {
     // Long-press to bring up the text editing controls.
     final Finder textFinder = find.byKey(editableTextKey);
     await tester.longPress(textFinder);
+    tester.state<EditableTextState>(textFinder).showToolbar();
     await tester.pump();
 
     await tester.tap(find.text('PASTE'));

packages/flutter/test/widgets/editable_text_test.dart

@@ -478,6 +478,45 @@ void main() {
         equals('TextInputAction.done'));
   });
 
+  testWidgets('can only show toolbar when there is text and a selection',
+      (WidgetTester tester) async {
+    await tester.pumpWidget(
+      MaterialApp(
+        home: EditableText(
+          backgroundCursorColor: Colors.grey,
+          controller: controller,
+          focusNode: focusNode,
+          style: textStyle,
+          cursorColor: cursorColor,
+          selectionControls: materialTextSelectionControls,
+        ),
+      ),
+    );
+
+    final EditableTextState state =
+        tester.state<EditableTextState>(find.byType(EditableText));
+
+    expect(state.showToolbar(), false);
+    await tester.pump();
+    expect(find.text('PASTE'), findsNothing);
+
+    controller.text = 'blah';
+    await tester.pump();
+    expect(state.showToolbar(), false);
+    await tester.pump();
+    expect(find.text('PASTE'), findsNothing);
+
+    // Select something. Doesn't really matter what.
+    state.renderEditable.selectWordsInRange(
+      from: const Offset(0, 0),
+      cause: SelectionChangedCause.tap,
+    );
+    await tester.pump();
+    expect(state.showToolbar(), true);
+    await tester.pump();
+    expect(find.text('PASTE'), findsOneWidget);
+  });
+
   testWidgets('Fires onChanged when text changes via TextSelectionOverlay',
       (WidgetTester tester) async {
     final GlobalKey<EditableTextState> editableTextKey =
@@ -513,6 +552,7 @@ void main() {
     // Long-press to bring up the text editing controls.
     final Finder textFinder = find.byKey(editableTextKey);
     await tester.longPress(textFinder);
+    tester.state<EditableTextState>(textFinder).showToolbar();
     await tester.pump();
 
     await tester.tap(find.text('PASTE'));