Selects a word on force tap (#25683)

* adds force press select word functionality

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

@@ -451,6 +451,18 @@ class _CupertinoTextFieldState extends State<CupertinoTextField> with AutomaticK
     _renderEditable.handleTapDown(details);
   }
 
+  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);
+  }
+
+  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);
+  }
+
   void _handleSingleTapUp(TapUpDetails details) {
     _renderEditable.selectWordEdge(cause: SelectionChangedCause.tap);
     _requestKeyboard();
@@ -648,6 +660,8 @@ class _CupertinoTextFieldState extends State<CupertinoTextField> with AutomaticK
                     : CupertinoColors.darkBackgroundGray,
             child: TextSelectionGestureDetector(
               onTapDown: _handleTapDown,
+              onForcePressStart: _handleForcePressStarted,
+              onForcePressEnd: _handleForcePressEnded,
               onSingleTapUp: _handleSingleTapUp,
               onSingleLongTapDown: _handleSingleLongTapDown,
               onDoubleTapDown: _handleDoubleTapDown,

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

@@ -543,6 +543,21 @@ class _TextFieldState extends State<TextField> with AutomaticKeepAliveClientMixi
     _startSplash(details);
   }
 
+  void _handleForcePressStarted(ForcePressDetails details) {
+    if (widget.selectionEnabled) {
+      switch (Theme.of(context).platform) {
+        case TargetPlatform.iOS:
+          // The cause is not technically double tap, but we would like to show
+          // the toolbar.
+          _renderEditable.selectWordsInRange(from: details.globalPosition, cause: SelectionChangedCause.doubleTap);
+          break;
+        case TargetPlatform.android:
+        case TargetPlatform.fuchsia:
+          break;
+      }
+    }
+  }
+
   void _handleSingleTapUp(TapUpDetails details) {
     if (widget.selectionEnabled) {
       switch (Theme.of(context).platform) {
@@ -706,6 +721,7 @@ class _TextFieldState extends State<TextField> with AutomaticKeepAliveClientMixi
         ignoring: !(widget.enabled ?? widget.decoration?.enabled ?? true),
         child: TextSelectionGestureDetector(
           onTapDown: _handleTapDown,
+          onForcePressStart: _handleForcePressStarted,
           onSingleTapUp: _handleSingleTapUp,
           onSingleTapCancel: _handleSingleTapCancel,
           onSingleLongTapDown: _handleSingleLongTapDown,

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

@@ -1184,12 +1184,29 @@ class RenderEditable extends RenderBox {
 
   /// Select a word around the location of the last tap down.
   void selectWord({@required SelectionChangedCause cause}) {
+    selectWordsInRange(from: _lastTapDownPosition, cause: cause);
+  }
+
+  /// Selects the set words of a paragraph in a given range of global positions.
+  ///
+  /// The first and last endpoints of the selection will always be at the
+  /// beginning and end of a word respectively.
+  void selectWordsInRange({@required Offset from, Offset to, @required SelectionChangedCause cause}) {
     assert(cause != null);
     _layoutText(constraints.maxWidth);
-    assert(_lastTapDownPosition != null);
     if (onSelectionChanged != null) {
-      final TextPosition position = _textPainter.getPositionForOffset(globalToLocal(_lastTapDownPosition));
-      onSelectionChanged(_selectWordAtOffset(position), this, cause);
+      final TextPosition firstPosition = _textPainter.getPositionForOffset(globalToLocal(from + -_paintOffset));
+      final TextSelection firstWord = _selectWordAtOffset(firstPosition);
+      final TextSelection lastWord = to == null ?
+        firstWord : _selectWordAtOffset(_textPainter.getPositionForOffset(globalToLocal(to + -_paintOffset)));
+
+      onSelectionChanged(
+        TextSelection(
+          baseOffset: firstWord.base.offset,
+          extentOffset: lastWord.extent.offset,
+          affinity: firstWord.affinity,
+        ), this, cause,
+      );
     }
   }
 

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

@@ -36,6 +36,7 @@ export 'package:flutter/gestures.dart' show
   ScaleEndDetails,
   TapDownDetails,
   TapUpDetails,
+  ForcePressDetails,
   Velocity;
 
 // Examples can assume:

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

@@ -612,6 +612,8 @@ class TextSelectionGestureDetector extends StatefulWidget {
   const TextSelectionGestureDetector({
     Key key,
     this.onTapDown,
+    this.onForcePressStart,
+    this.onForcePressEnd,
     this.onSingleTapUp,
     this.onSingleTapCancel,
     this.onSingleLongTapDown,
@@ -626,6 +628,14 @@ class TextSelectionGestureDetector extends StatefulWidget {
   /// to not qualify as taps (e.g. pans and flings).
   final GestureTapDownCallback onTapDown;
 
+  /// Called when a pointer has tapped down and the force of the pointer has
+  /// just become greater than [ForcePressGestureDetector.startPressure].
+  final GestureForcePressStartCallback onForcePressStart;
+
+  /// Called when a pointer that had previously triggered [onForcePressStart] is
+  /// lifted off the screen.
+  final GestureForcePressEndCallback onForcePressEnd;
+
   /// Called for each distinct tap except for every second tap of a double tap.
   /// For example, if the detector was configured [onSingleTapDown] and
   /// [onDoubleTapDown], three quick taps would be recognized as a single tap
@@ -712,6 +722,18 @@ class _TextSelectionGestureDetectorState extends State<TextSelectionGestureDetec
     }
   }
 
+  void _forcePressStarted(ForcePressDetails details) {
+    _doubleTapTimer?.cancel();
+    _doubleTapTimer = null;
+   if (widget.onForcePressStart != null)
+     widget.onForcePressStart(details);
+  }
+
+  void _forcePressEnded(ForcePressDetails details) {
+    if (widget.onForcePressEnd != null)
+      widget.onForcePressEnd(details);
+  }
+
   void _handleLongPress() {
     if (!_isDoubleTap && widget.onSingleLongTapDown != null) {
       widget.onSingleLongTapDown();
@@ -739,6 +761,8 @@ class _TextSelectionGestureDetectorState extends State<TextSelectionGestureDetec
     return GestureDetector(
       onTapDown: _handleTapDown,
       onTapUp: _handleTapUp,
+      onForcePressStart: _forcePressStarted,
+      onForcePressEnd: _forcePressEnded,
       onTapCancel: _handleTapCancel,
       onLongPress: _handleLongPress,
       excludeFromSemantics: true,

packages/flutter/test/cupertino/text_field_test.dart

@@ -1099,6 +1099,38 @@ void main() {
     },
   );
 
+  testWidgets('force press selects word', (WidgetTester tester) async {
+      final TextEditingController controller = TextEditingController(
+        text: 'Atwater Peel Sherbrooke Bonaventure',
+      );
+      await tester.pumpWidget(
+        CupertinoApp(
+          home: Center(
+            child: CupertinoTextField(
+              controller: controller,
+            ),
+          ),
+        ),
+      );
+
+      final Offset textfieldStart = tester.getTopLeft(find.byType(CupertinoTextField));
+
+      const int pointerValue = 1;
+      final TestGesture gesture =
+      await tester.startGesture(textfieldStart + const Offset(150.0, 5.0));
+      await gesture.updateWithCustomEvent(PointerMoveEvent(pointer: pointerValue, position: textfieldStart + const Offset(150.0, 5.0), pressure: 0.5, pressureMin: 0, pressureMax: 1));
+      // We expect the force press to select a word at the given location.
+      expect(
+        controller.selection,
+        const TextSelection(baseOffset: 8, extentOffset: 12),
+      );
+
+      await gesture.up();
+      await tester.pumpAndSettle();
+      expect(find.byType(CupertinoButton), findsNWidgets(3));
+    },
+  );
+
   testWidgets(
     'text field respects theme',
     (WidgetTester tester) async {

packages/flutter/test/material/text_field_test.dart

@@ -12,6 +12,7 @@ import 'package:flutter/material.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:flutter/rendering.dart';
 import 'package:flutter/services.dart';
+import 'package:flutter/foundation.dart';
 import 'package:flutter/gestures.dart' show DragStartBehavior;
 
 import '../widgets/semantics_tester.dart';
@@ -4204,6 +4205,70 @@ void main() {
     },
   );
 
+  testWidgets('force press does not select a word on (android)', (WidgetTester tester) async {
+    debugDefaultTargetPlatformOverride = TargetPlatform.android;
+    final TextEditingController controller = TextEditingController(
+      text: 'Atwater Peel Sherbrooke Bonaventure',
+    );
+    await tester.pumpWidget(
+      MaterialApp(
+        home: Material(
+          child: TextField(
+            controller: controller,
+          ),
+        ),
+      ),
+    );
+
+    final Offset textfieldStart = tester.getTopLeft(find.byType(TextField));
+
+    const int pointerValue = 1;
+    final TestGesture gesture =
+    await tester.startGesture(textfieldStart + const Offset(150.0, 5.0));
+    await gesture.updateWithCustomEvent(PointerMoveEvent(pointer: pointerValue, position: textfieldStart + const Offset(150.0, 5.0), pressure: 0.5, pressureMin: 0, pressureMax: 1));
+
+    // We don't want this gesture to select any word on Android.
+    expect(controller.selection, const TextSelection.collapsed(offset: -1));
+
+    await gesture.up();
+    await tester.pumpAndSettle();
+    expect(find.byType(FlatButton), findsNothing);
+    debugDefaultTargetPlatformOverride = null;
+  });
+
+  testWidgets('force press selects word (iOS)', (WidgetTester tester) async {
+    debugDefaultTargetPlatformOverride = TargetPlatform.iOS;
+    final TextEditingController controller = TextEditingController(
+      text: 'Atwater Peel Sherbrooke Bonaventure',
+    );
+    await tester.pumpWidget(
+      CupertinoApp(
+        home: Center(
+          child: CupertinoTextField(
+            controller: controller,
+          ),
+        ),
+      ),
+    );
+
+    final Offset textfieldStart = tester.getTopLeft(find.byType(CupertinoTextField));
+
+    const int pointerValue = 1;
+    final TestGesture gesture =
+    await tester.startGesture(textfieldStart + const Offset(150.0, 5.0));
+    await gesture.updateWithCustomEvent(PointerMoveEvent(pointer: pointerValue, position: textfieldStart + const Offset(150.0, 5.0), pressure: 0.5, pressureMin: 0, pressureMax: 1));
+    // We expect the force press to select a word at the given location.
+    expect(
+      controller.selection,
+      const TextSelection(baseOffset: 8, extentOffset: 12),
+    );
+
+    await gesture.up();
+    await tester.pumpAndSettle();
+    expect(find.byType(CupertinoButton), findsNWidgets(3));
+    debugDefaultTargetPlatformOverride = null;
+  });
+
   testWidgets('default TextField debugFillProperties', (WidgetTester tester) async {
     final DiagnosticPropertiesBuilder builder = DiagnosticPropertiesBuilder();
 

packages/flutter/test/widgets/text_selection_test.dart

@@ -11,12 +11,16 @@ void main() {
   int singleTapCancelCount;
   int singleLongTapDownCount;
   int doubleTapDownCount;
+  int forcePressStartCount;
+  int forcePressEndCount;
 
   void _handleTapDown(TapDownDetails details) { tapCount++; }
   void _handleSingleTapUp(TapUpDetails details) { singleTapUpCount++; }
   void _handleSingleTapCancel() { singleTapCancelCount++; }
   void _handleSingleLongTapDown() { singleLongTapDownCount++; }
   void _handleDoubleTapDown(TapDownDetails details) { doubleTapDownCount++; }
+  void _handleForcePressStart(ForcePressDetails details) { forcePressStartCount++; }
+  void _handleForcePressEnd(ForcePressDetails details) { forcePressEndCount++; }
 
   setUp(() {
     tapCount = 0;
@@ -24,6 +28,8 @@ void main() {
     singleTapCancelCount = 0;
     singleLongTapDownCount = 0;
     doubleTapDownCount = 0;
+    forcePressStartCount = 0;
+    forcePressEndCount = 0;
   });
 
   Future<void> pumpGestureDetector(WidgetTester tester) async {
@@ -35,6 +41,8 @@ void main() {
         onSingleTapCancel: _handleSingleTapCancel,
         onSingleLongTapDown: _handleSingleLongTapDown,
         onDoubleTapDown: _handleDoubleTapDown,
+        onForcePressStart: _handleForcePressStart,
+        onForcePressEnd: _handleForcePressEnd,
         child: Container(),
       ),
     );
@@ -142,4 +150,54 @@ void main() {
     expect(doubleTapDownCount, 0);
     expect(singleLongTapDownCount, 0);
   });
+
+  testWidgets('a force press intiates a force press', (WidgetTester tester) async {
+    await pumpGestureDetector(tester);
+
+    const int pointerValue = 1;
+    TestGesture gesture = await tester.startGesture(const Offset(400.0, 50.0), pointer: pointerValue);
+    await gesture.updateWithCustomEvent(const PointerMoveEvent(pointer: pointerValue, position: Offset(0.0, 0.0), pressure: 0.5, pressureMin: 0, pressureMax: 1));
+    await gesture.up();
+    await tester.pumpAndSettle();
+
+    gesture = await tester.startGesture(const Offset(400.0, 50.0), pointer: pointerValue);
+    await gesture.updateWithCustomEvent(const PointerMoveEvent(pointer: pointerValue, position: Offset(0.0, 0.0), pressure: 0.5, pressureMin: 0, pressureMax: 1));
+    await gesture.up();
+    await tester.pump(const Duration(milliseconds: 20));
+
+    gesture = await tester.startGesture(const Offset(400.0, 50.0), pointer: pointerValue);
+    await gesture.updateWithCustomEvent(const PointerMoveEvent(pointer: pointerValue, position: Offset(0.0, 0.0), pressure: 0.5, pressureMin: 0, pressureMax: 1));
+    await gesture.up();
+    await tester.pump(const Duration(milliseconds: 20));
+
+    gesture = await tester.startGesture(const Offset(400.0, 50.0), pointer: pointerValue);
+    await gesture.updateWithCustomEvent(const PointerMoveEvent(pointer: pointerValue, position: Offset(0.0, 0.0), pressure: 0.5, pressureMin: 0, pressureMax: 1));
+    await gesture.up();
+
+    expect(forcePressStartCount, 4);
+  });
+
+  testWidgets('a tap and then force press intiates a force press and not a double tap', (WidgetTester tester) async {
+    await pumpGestureDetector(tester);
+
+    const int pointerValue = 1;
+    TestGesture gesture = await tester.startGesture(const Offset(400.0, 50.0), pointer: pointerValue);
+
+    // Initiate a quick tap.
+    await gesture.updateWithCustomEvent(const PointerMoveEvent(pointer: pointerValue, position: Offset(0.0, 0.0), pressure: 0.0, pressureMin: 0, pressureMax: 1));
+    await tester.pump(const Duration(milliseconds: 50));
+    await gesture.up();
+
+    // Initiate a force tap.
+    gesture = await tester.startGesture(const Offset(400.0, 50.0), pointer: pointerValue);
+    await gesture.updateWithCustomEvent(const PointerMoveEvent(pointer: pointerValue, position: Offset(0.0, 0.0), pressure: 0.5, pressureMin: 0, pressureMax: 1));
+    expect(forcePressStartCount, 1);
+
+    await tester.pump(const Duration(milliseconds: 50));
+    await gesture.up();
+    await tester.pumpAndSettle();
+
+    expect(forcePressEndCount, 1);
+    expect(doubleTapDownCount, 0);
+  });
 }