Text selection via mouse (flutter#28290)

packages/flutter/lib/src/gestures/eager.dart

@@ -12,8 +12,13 @@ import 'recognizer.dart';
 /// all touch events inside the view bounds to the embedded Android view.
 /// See [AndroidView.gestureRecognizers] for more details.
 class EagerGestureRecognizer extends OneSequenceGestureRecognizer {
+  /// Create an eager gesture recognizer.
+  ///
+  /// {@macro flutter.gestures.gestureRecognizer.kind}
+  EagerGestureRecognizer({ PointerDeviceKind kind }): super(kind: kind);
+
   @override
-  void addPointer(PointerDownEvent event) {
+  void addAllowedPointer(PointerDownEvent event) {
     // We call startTrackingPointer as this is where OneSequenceGestureRecognizer joins the arena.
     startTrackingPointer(event.pointer);
     resolve(GestureDisposition.accepted);

packages/flutter/lib/src/gestures/force_press.dart

@@ -116,16 +116,19 @@ class ForcePressGestureRecognizer extends OneSequenceGestureRecognizer {
   /// The [interpolation] callback must always return a value in the range 0.0
   /// to 1.0 for values of `pressure` that are between `pressureMin` and
   /// `pressureMax`.
+  ///
+  /// {@macro flutter.gestures.gestureRecognizer.kind}
   ForcePressGestureRecognizer({
     this.startPressure = 0.4,
     this.peakPressure = 0.85,
     this.interpolation = _inverseLerp,
     Object debugOwner,
+    PointerDeviceKind kind,
   }) : assert(startPressure != null),
        assert(peakPressure != null),
        assert(interpolation != null),
        assert(peakPressure > startPressure),
-       super(debugOwner: debugOwner);
+       super(debugOwner: debugOwner, kind: kind);
 
   /// A pointer is in contact with the screen and has just pressed with a force
   /// exceeding the [startPressure]. Consequently, if there were other gesture
@@ -205,7 +208,7 @@ class ForcePressGestureRecognizer extends OneSequenceGestureRecognizer {
   _ForceState _state = _ForceState.ready;
 
   @override
-  void addPointer(PointerEvent event) {
+  void addAllowedPointer(PointerEvent event) {
     // If the device has a maximum pressure of less than or equal to 1, it
     // doesn't have touch pressure sensing capabilities. Do not participate
     // in the gesture arena.

packages/flutter/lib/src/gestures/long_press.dart

@@ -123,10 +123,12 @@ class LongPressGestureRecognizer extends PrimaryPointerGestureRecognizer {
   /// can be moved without limit once the long press is accepted.
   LongPressGestureRecognizer({
     double postAcceptSlopTolerance,
+    PointerDeviceKind kind,
     Object debugOwner,
   }) : super(
     deadline: kLongPressTimeout,
     postAcceptSlopTolerance: postAcceptSlopTolerance,
+    kind: kind,
     debugOwner: debugOwner,
   );
 

packages/flutter/lib/src/gestures/monodrag.dart

@@ -52,11 +52,14 @@ abstract class DragGestureRecognizer extends OneSequenceGestureRecognizer {
   /// Initialize the object.
   ///
   /// [dragStartBehavior] must not be null.
+  ///
+  /// {@macro flutter.gestures.gestureRecognizer.kind}
   DragGestureRecognizer({
     Object debugOwner,
+    PointerDeviceKind kind,
     this.dragStartBehavior = DragStartBehavior.start,
   }) : assert(dragStartBehavior != null),
-       super(debugOwner: debugOwner);
+       super(debugOwner: debugOwner, kind: kind);
 
   /// Configure the behavior of offsets sent to [onStart].
   ///
@@ -147,7 +150,7 @@ abstract class DragGestureRecognizer extends OneSequenceGestureRecognizer {
   final Map<int, VelocityTracker> _velocityTrackers = <int, VelocityTracker>{};
 
   @override
-  void addPointer(PointerEvent event) {
+  void addAllowedPointer(PointerEvent event) {
     startTrackingPointer(event.pointer);
     _velocityTrackers[event.pointer] = VelocityTracker();
     if (_state == _DragState.ready) {
@@ -296,7 +299,12 @@ abstract class DragGestureRecognizer extends OneSequenceGestureRecognizer {
 ///    track each touch point independently.
 class VerticalDragGestureRecognizer extends DragGestureRecognizer {
   /// Create a gesture recognizer for interactions in the vertical axis.
-  VerticalDragGestureRecognizer({ Object debugOwner }) : super(debugOwner: debugOwner);
+  ///
+  /// {@macro flutter.gestures.gestureRecognizer.kind}
+  VerticalDragGestureRecognizer({
+    Object debugOwner,
+    PointerDeviceKind kind,
+  }) : super(debugOwner: debugOwner, kind: kind);
 
   @override
   bool _isFlingGesture(VelocityEstimate estimate) {
@@ -330,7 +338,12 @@ class VerticalDragGestureRecognizer extends DragGestureRecognizer {
 ///    track each touch point independently.
 class HorizontalDragGestureRecognizer extends DragGestureRecognizer {
   /// Create a gesture recognizer for interactions in the horizontal axis.
-  HorizontalDragGestureRecognizer({ Object debugOwner }) : super(debugOwner: debugOwner);
+  ///
+  /// {@macro flutter.gestures.gestureRecognizer.kind}
+  HorizontalDragGestureRecognizer({
+    Object debugOwner,
+    PointerDeviceKind kind,
+  }) : super(debugOwner: debugOwner, kind: kind);
 
   @override
   bool _isFlingGesture(VelocityEstimate estimate) {

packages/flutter/lib/src/gestures/multidrag.dart

@@ -189,7 +189,10 @@ abstract class MultiDragPointerState {
 ///    start after a long-press gesture.
 abstract class MultiDragGestureRecognizer<T extends MultiDragPointerState> extends GestureRecognizer {
   /// Initialize the object.
-  MultiDragGestureRecognizer({ @required Object debugOwner }) : super(debugOwner: debugOwner);
+  MultiDragGestureRecognizer({
+    @required Object debugOwner,
+    PointerDeviceKind kind,
+  }) : super(debugOwner: debugOwner, kind: kind);
 
   /// Called when this class recognizes the start of a drag gesture.
   ///
@@ -200,7 +203,7 @@ abstract class MultiDragGestureRecognizer<T extends MultiDragPointerState> exten
   Map<int, T> _pointers = <int, T>{};
 
   @override
-  void addPointer(PointerDownEvent event) {
+  void addAllowedPointer(PointerDownEvent event) {
     assert(_pointers != null);
     assert(event.pointer != null);
     assert(event.position != null);
@@ -334,7 +337,10 @@ class _ImmediatePointerState extends MultiDragPointerState {
 ///    start after a long-press gesture.
 class ImmediateMultiDragGestureRecognizer extends MultiDragGestureRecognizer<_ImmediatePointerState> {
   /// Create a gesture recognizer for tracking multiple pointers at once.
-  ImmediateMultiDragGestureRecognizer({ Object debugOwner }) : super(debugOwner: debugOwner);
+  ImmediateMultiDragGestureRecognizer({
+    Object debugOwner,
+    PointerDeviceKind kind,
+  }) : super(debugOwner: debugOwner, kind: kind);
 
   @override
   _ImmediatePointerState createNewPointerState(PointerDownEvent event) {
@@ -380,7 +386,10 @@ class _HorizontalPointerState extends MultiDragPointerState {
 class HorizontalMultiDragGestureRecognizer extends MultiDragGestureRecognizer<_HorizontalPointerState> {
   /// Create a gesture recognizer for tracking multiple pointers at once
   /// but only if they first move horizontally.
-  HorizontalMultiDragGestureRecognizer({ Object debugOwner }) : super(debugOwner: debugOwner);
+  HorizontalMultiDragGestureRecognizer({
+    Object debugOwner,
+    PointerDeviceKind kind,
+  }) : super(debugOwner: debugOwner, kind: kind);
 
   @override
   _HorizontalPointerState createNewPointerState(PointerDownEvent event) {
@@ -426,7 +435,10 @@ class _VerticalPointerState extends MultiDragPointerState {
 class VerticalMultiDragGestureRecognizer extends MultiDragGestureRecognizer<_VerticalPointerState> {
   /// Create a gesture recognizer for tracking multiple pointers at once
   /// but only if they first move vertically.
-  VerticalMultiDragGestureRecognizer({ Object debugOwner }) : super(debugOwner: debugOwner);
+  VerticalMultiDragGestureRecognizer({
+    Object debugOwner,
+    PointerDeviceKind kind,
+  }) : super(debugOwner: debugOwner, kind: kind);
 
   @override
   _VerticalPointerState createNewPointerState(PointerDownEvent event) {
@@ -528,8 +540,9 @@ class DelayedMultiDragGestureRecognizer extends MultiDragGestureRecognizer<_Dela
   DelayedMultiDragGestureRecognizer({
     this.delay = kLongPressTimeout,
     Object debugOwner,
+    PointerDeviceKind kind,
   }) : assert(delay != null),
-       super(debugOwner: debugOwner);
+       super(debugOwner: debugOwner, kind: kind);
 
   /// The amount of time the pointer must remain in the same place for the drag
   /// to be recognized.

packages/flutter/lib/src/gestures/multitap.dart

@@ -69,7 +69,12 @@ class _TapTracker {
 /// quick succession.
 class DoubleTapGestureRecognizer extends GestureRecognizer {
   /// Create a gesture recognizer for double taps.
-  DoubleTapGestureRecognizer({ Object debugOwner }) : super(debugOwner: debugOwner);
+  ///
+  /// {@macro flutter.gestures.gestureRecognizer.kind}
+  DoubleTapGestureRecognizer({
+    Object debugOwner,
+    PointerDeviceKind kind,
+  }) : super(debugOwner: debugOwner, kind: kind);
 
   // Implementation notes:
   // The double tap recognizer can be in one of four states. There's no
@@ -100,7 +105,7 @@ class DoubleTapGestureRecognizer extends GestureRecognizer {
   final Map<int, _TapTracker> _trackers = <int, _TapTracker>{};
 
   @override
-  void addPointer(PointerEvent event) {
+  void addAllowedPointer(PointerEvent event) {
     // Ignore out-of-bounds second taps.
     if (_firstTap != null &&
         !_firstTap.isWithinTolerance(event, kDoubleTapSlop))
@@ -318,7 +323,8 @@ class MultiTapGestureRecognizer extends GestureRecognizer {
   MultiTapGestureRecognizer({
     this.longTapDelay = Duration.zero,
     Object debugOwner,
-  }) : super(debugOwner: debugOwner);
+    PointerDeviceKind kind,
+  }) : super(debugOwner: debugOwner, kind: kind);
 
   /// A pointer that might cause a tap has contacted the screen at a particular
   /// location.
@@ -345,7 +351,7 @@ class MultiTapGestureRecognizer extends GestureRecognizer {
   final Map<int, _TapGesture> _gestureMap = <int, _TapGesture>{};
 
   @override
-  void addPointer(PointerEvent event) {
+  void addAllowedPointer(PointerEvent event) {
     assert(!_gestureMap.containsKey(event.pointer));
     _gestureMap[event.pointer] = _TapGesture(
       gestureRecognizer: this,

packages/flutter/lib/src/gestures/recognizer.dart

@@ -33,7 +33,7 @@ typedef RecognizerCallback<T> = T Function();
 ///
 ///   * [DragGestureRecognizer.dragStartBehavior], which gives an example for the different behaviors.
 enum DragStartBehavior {
-  /// Set the initial offset, at the position where the first down even was
+  /// Set the initial offset, at the position where the first down event was
   /// detected.
   down,
 
@@ -58,14 +58,24 @@ abstract class GestureRecognizer extends GestureArenaMember with DiagnosticableT
   ///
   /// The argument is optional and is only used for debug purposes (e.g. in the
   /// [toString] serialization).
-  GestureRecognizer({ this.debugOwner });
+  ///
+  /// {@template flutter.gestures.gestureRecognizer.kind}
+  /// It's possible to limit this recognizer to a specific [PointerDeviceKind]
+  /// by providing the optional [kind] argument. If [kind] is null,
+  /// the recognizer will accept pointer events from all device kinds.
+  /// {@endtemplate}
+  GestureRecognizer({ this.debugOwner, PointerDeviceKind kind }) : _kind = kind;
 
   /// The recognizer's owner.
   ///
   /// This is used in the [toString] serialization to report the object for which
   /// this gesture recognizer was created, to aid in debugging.
   final Object debugOwner;
 
+  /// The kind of device that's allowed to be recognized. If null, events from
+  /// all device kinds will be tracked and recognized.
+  final PointerDeviceKind _kind;
+
   /// Registers a new pointer that might be relevant to this gesture
   /// detector.
   ///
@@ -78,7 +88,43 @@ abstract class GestureRecognizer extends GestureArenaMember with DiagnosticableT
   /// subsequent events for this pointer, and to add the pointer to
   /// the global gesture arena manager (see [GestureArenaManager]) to track
   /// that pointer.
-  void addPointer(PointerDownEvent event);
+  ///
+  /// This method is called for each and all pointers being added. In
+  /// most cases, you want to override [addAllowedPointer] instead.
+  void addPointer(PointerDownEvent event) {
+    if (isPointerAllowed(event)) {
+      addAllowedPointer(event);
+    } else {
+      handleNonAllowedPointer(event);
+    }
+  }
+
+  /// Registers a new pointer that's been checked to be allowed by this gesture
+  /// recognizer.
+  ///
+  /// Subclasses of [GestureRecognizer] are supposed to override this method
+  /// instead of [addPointer] because [addPointer] will be called for each
+  /// pointer being added while [addAllowedPointer] is only called for pointers
+  /// that are allowed by this recognizer.
+  @protected
+  void addAllowedPointer(PointerDownEvent event) { }
+
+  /// Handles a pointer being added that's not allowed by this recognizer.
+  ///
+  /// Subclasses can override this method and reject the gesture.
+  ///
+  /// See:
+  /// - [OneSequenceGestureRecognizer.handleNonAllowedPointer].
+  @protected
+  void handleNonAllowedPointer(PointerDownEvent event) { }
+
+  /// Checks whether or not a pointer is allowed to be tracked by this recognizer.
+  @protected
+  bool isPointerAllowed(PointerDownEvent event) {
+    // Currently, it only checks for device kind. But in the future we could check
+    // for other things e.g. mouse button.
+    return _kind == null || _kind == event.kind;
+  }
 
   /// Releases any resources used by the object.
   ///
@@ -151,11 +197,21 @@ abstract class GestureRecognizer extends GestureArenaMember with DiagnosticableT
 /// simultaneous touches to each result in a separate tap.
 abstract class OneSequenceGestureRecognizer extends GestureRecognizer {
   /// Initialize the object.
-  OneSequenceGestureRecognizer({ Object debugOwner }) : super(debugOwner: debugOwner);
+  ///
+  /// {@macro flutter.gestures.gestureRecognizer.kind}
+  OneSequenceGestureRecognizer({
+    Object debugOwner,
+    PointerDeviceKind kind,
+  }) : super(debugOwner: debugOwner, kind: kind);
 
   final Map<int, GestureArenaEntry> _entries = <int, GestureArenaEntry>{};
   final Set<int> _trackedPointers = HashSet<int>();
 
+  @override
+  void handleNonAllowedPointer(PointerDownEvent event) {
+    resolve(GestureDisposition.rejected);
+  }
+
   /// Called when a pointer event is routed to this recognizer.
   @protected
   void handleEvent(PointerEvent event);
@@ -291,11 +347,14 @@ enum GestureRecognizerState {
 /// in the gesture arena, the gesture will be rejected.
 abstract class PrimaryPointerGestureRecognizer extends OneSequenceGestureRecognizer {
   /// Initializes the [deadline] field during construction of subclasses.
+  ///
+  /// {@macro flutter.gestures.gestureRecognizer.kind}
   PrimaryPointerGestureRecognizer({
     this.deadline,
     this.preAcceptSlopTolerance = kTouchSlop,
     this.postAcceptSlopTolerance = kTouchSlop,
     Object debugOwner,
+    PointerDeviceKind kind,
   }) : assert(
          preAcceptSlopTolerance == null || preAcceptSlopTolerance >= 0,
          'The preAcceptSlopTolerance must be positive or null',
@@ -304,7 +363,7 @@ abstract class PrimaryPointerGestureRecognizer extends OneSequenceGestureRecogni
          postAcceptSlopTolerance == null || postAcceptSlopTolerance >= 0,
          'The postAcceptSlopTolerance must be positive or null',
        ),
-       super(debugOwner: debugOwner);
+       super(debugOwner: debugOwner, kind: kind);
 
   /// If non-null, the recognizer will call [didExceedDeadline] after this
   /// amount of time has elapsed since starting to track the primary pointer.
@@ -346,7 +405,7 @@ abstract class PrimaryPointerGestureRecognizer extends OneSequenceGestureRecogni
   Timer _timer;
 
   @override
-  void addPointer(PointerDownEvent event) {
+  void addAllowedPointer(PointerDownEvent event) {
     startTrackingPointer(event.pointer);
     if (state == GestureRecognizerState.ready) {
       state = GestureRecognizerState.possible;

packages/flutter/lib/src/gestures/scale.dart

@@ -183,7 +183,12 @@ class _LineBetweenPointers{
 /// are no longer in contact with the screen, the recognizer calls [onEnd].
 class ScaleGestureRecognizer extends OneSequenceGestureRecognizer {
   /// Create a gesture recognizer for interactions intended for scaling content.
-  ScaleGestureRecognizer({ Object debugOwner }) : super(debugOwner: debugOwner);
+  ///
+  /// {@macro flutter.gestures.gestureRecognizer.kind}
+  ScaleGestureRecognizer({
+    Object debugOwner,
+    PointerDeviceKind kind,
+  }) : super(debugOwner: debugOwner, kind: kind);
 
   /// The pointers in contact with the screen have established a focal point and
   /// initial scale of 1.0.
@@ -239,7 +244,7 @@ class ScaleGestureRecognizer extends OneSequenceGestureRecognizer {
   }
 
   @override
-  void addPointer(PointerEvent event) {
+  void addAllowedPointer(PointerEvent event) {
     startTrackingPointer(event.pointer);
     _velocityTrackers[event.pointer] = VelocityTracker();
     if (_state == _ScaleState.ready) {