packages/flutter/lib/src/gestures/long_press.dart - mirrors/flutter - Git at Google

 // 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 'arena.dart';
 import 'constants.dart';
 import 'events.dart';
 import 'recognizer.dart';
 import 'velocity_tracker.dart';

 /// Callback signature for [LongPressGestureRecognizer.onLongPress].
 ///
 /// Called when a pointer has remained in contact with the screen at the
 /// same location for a long period of time.
 typedef GestureLongPressCallback = void Function();

 /// Callback signature for [LongPressGestureRecognizer.onLongPressUp].
 ///
 /// Called when a pointer stops contacting the screen after a long press
 /// gesture was detected.
 typedef GestureLongPressUpCallback = void Function();

 /// Callback signature for [LongPressGestureRecognizer.onLongPressStart].
 ///
 /// Called when a pointer has remained in contact with the screen at the
 /// same location for a long period of time. Also reports the long press down
 /// position.
 typedef GestureLongPressStartCallback = void Function(LongPressStartDetails details);

 /// Callback signature for [LongPressGestureRecognizer.onLongPressMoveUpdate].
 ///
 /// Called when a pointer is moving after being held in contact at the same
 /// location for a long period of time. Reports the new position and its offset
 /// from the original down position.
 typedef GestureLongPressMoveUpdateCallback = void Function(LongPressMoveUpdateDetails details);

 /// Callback signature for [LongPressGestureRecognizer.onLongPressEnd].
 ///
 /// Called when a pointer stops contacting the screen after a long press
 /// gesture was detected. Also reports the position where the pointer stopped
 /// contacting the screen.
 typedef GestureLongPressEndCallback = void Function(LongPressEndDetails details);

 /// Details for callbacks that use [GestureLongPressStartCallback].
 ///
 /// See also:
 ///
 ///  * [LongPressGestureRecognizer.onLongPressStart], which uses [GestureLongPressStartCallback].
 ///  * [LongPressMoveUpdateDetails], the details for [GestureLongPressMoveUpdateCallback]
 ///  * [LongPressEndDetails], the details for [GestureLongPressEndCallback].
 class LongPressStartDetails {
   /// Creates the details for a [GestureLongPressStartCallback].
   ///
   /// The [globalPosition] argument must not be null.
   const LongPressStartDetails({
     this.globalPosition = Offset.zero,
     Offset? localPosition,
   }) : assert(globalPosition != null),
        localPosition = localPosition ?? globalPosition;

   /// The global position at which the pointer contacted the screen.
   final Offset globalPosition;

   /// The local position at which the pointer contacted the screen.
   final Offset localPosition;
 }

 /// Details for callbacks that use [GestureLongPressMoveUpdateCallback].
 ///
 /// See also:
 ///
 ///  * [LongPressGestureRecognizer.onLongPressMoveUpdate], which uses [GestureLongPressMoveUpdateCallback].
 ///  * [LongPressEndDetails], the details for [GestureLongPressEndCallback]
 ///  * [LongPressStartDetails], the details for [GestureLongPressStartCallback].
 class LongPressMoveUpdateDetails {
   /// Creates the details for a [GestureLongPressMoveUpdateCallback].
   ///
   /// The [globalPosition] and [offsetFromOrigin] arguments must not be null.
   const LongPressMoveUpdateDetails({
     this.globalPosition = Offset.zero,
     Offset? localPosition,
     this.offsetFromOrigin = Offset.zero,
     Offset? localOffsetFromOrigin,
   }) : assert(globalPosition != null),
        assert(offsetFromOrigin != null),
        localPosition = localPosition ?? globalPosition,
        localOffsetFromOrigin = localOffsetFromOrigin ?? offsetFromOrigin;

   /// The global position of the pointer when it triggered this update.
   final Offset globalPosition;

   /// The local position of the pointer when it triggered this update.
   final Offset localPosition;

   /// A delta offset from the point where the long press drag initially contacted
   /// the screen to the point where the pointer is currently located (the
   /// present [globalPosition]) when this callback is triggered.
   final Offset offsetFromOrigin;

   /// A local delta offset from the point where the long press drag initially contacted
   /// the screen to the point where the pointer is currently located (the
   /// present [localPosition]) when this callback is triggered.
   final Offset localOffsetFromOrigin;
 }

 /// Details for callbacks that use [GestureLongPressEndCallback].
 ///
 /// See also:
 ///
 ///  * [LongPressGestureRecognizer.onLongPressEnd], which uses [GestureLongPressEndCallback].
 ///  * [LongPressMoveUpdateDetails], the details for [GestureLongPressMoveUpdateCallback]
 ///  * [LongPressStartDetails], the details for [GestureLongPressStartCallback].
 class LongPressEndDetails {
   /// Creates the details for a [GestureLongPressEndCallback].
   ///
   /// The [globalPosition] argument must not be null.
   const LongPressEndDetails({
     this.globalPosition = Offset.zero,
     Offset? localPosition,
     this.velocity = Velocity.zero,
   }) : assert(globalPosition != null),
        localPosition = localPosition ?? globalPosition;

   /// The global position at which the pointer lifted from the screen.
   final Offset globalPosition;

   /// The local position at which the pointer contacted the screen.
   final Offset localPosition;

   /// The pointer's velocity when it stopped contacting the screen.
   ///
   /// Defaults to zero if not specified in the constructor.
   final Velocity velocity;
 }

 /// Recognizes when the user has pressed down at the same location for a long
 /// period of time.
 ///
 /// The gesture must not deviate in position from its touch down point for 500ms
 /// until it's recognized. Once the gesture is accepted, the finger can be
 /// moved, triggering [onLongPressMoveUpdate] callbacks, unless the
 /// [postAcceptSlopTolerance] constructor argument is specified.
 ///
 /// [LongPressGestureRecognizer] may compete on pointer events of
 /// [kPrimaryButton], [kSecondaryButton], and/or [kTertiaryButton] if at least
 /// one corresponding callback is non-null. If it has no callbacks, it is a no-op.
 class LongPressGestureRecognizer extends PrimaryPointerGestureRecognizer {
   /// Creates a long-press gesture recognizer.
   ///
   /// Consider assigning the [onLongPressStart] callback after creating this
   /// object.
   ///
   /// The [postAcceptSlopTolerance] argument can be used to specify a maximum
   /// allowed distance for the gesture to deviate from the starting point once
   /// the long press has triggered. If the gesture deviates past that point,
   /// subsequent callbacks ([onLongPressMoveUpdate], [onLongPressUp],
   /// [onLongPressEnd]) will stop. Defaults to null, which means the gesture
   /// can be moved without limit once the long press is accepted.
   ///
   /// The [duration] argument can be used to overwrite the default duration
   /// after which the long press will be recognized.
   LongPressGestureRecognizer({
     Duration? duration,
     double? postAcceptSlopTolerance,
     PointerDeviceKind? kind,
     Object? debugOwner,
   }) : super(
           deadline: duration ?? kLongPressTimeout,
           postAcceptSlopTolerance: postAcceptSlopTolerance,
           kind: kind,
           debugOwner: debugOwner,
         );

   bool _longPressAccepted = false;
   OffsetPair? _longPressOrigin;
   // The buttons sent by `PointerDownEvent`. If a `PointerMoveEvent` comes with a
   // different set of buttons, the gesture is canceled.
   int? _initialButtons;

   /// Called when a long press gesture by a primary button has been recognized.
   ///
   /// See also:
   ///
   ///  * [kPrimaryButton], the button this callback responds to.
   ///  * [onLongPressStart], which has the same timing but has data for the
   ///    press location.
   GestureLongPressCallback? onLongPress;

   /// Called when a long press gesture by a primary button has been recognized.
   ///
   /// See also:
   ///
   ///  * [kPrimaryButton], the button this callback responds to.
   ///  * [onLongPress], which has the same timing but without details.
   ///  * [LongPressStartDetails], which is passed as an argument to this callback.
   GestureLongPressStartCallback? onLongPressStart;

   /// Called when moving after the long press by a primary button is recognized.
   ///
   /// See also:
   ///
   ///  * [kPrimaryButton], the button this callback responds to.
   ///  * [LongPressMoveUpdateDetails], which is passed as an argument to this
   ///    callback.
   GestureLongPressMoveUpdateCallback? onLongPressMoveUpdate;

   /// Called when the pointer stops contacting the screen after a long-press
   /// by a primary button.
   ///
   /// See also:
   ///
   ///  * [kPrimaryButton], the button this callback responds to.
   ///  * [onLongPressEnd], which has the same timing but has data for the up
   ///    gesture location.
   GestureLongPressUpCallback? onLongPressUp;

   /// Called when the pointer stops contacting the screen after a long-press
   /// by a primary button.
   ///
   /// See also:
   ///
   ///  * [kPrimaryButton], the button this callback responds to.
   ///  * [onLongPressUp], which has the same timing, but without details.
   ///  * [LongPressEndDetails], which is passed as an argument to this
   ///    callback.
   GestureLongPressEndCallback? onLongPressEnd;

   /// Called when a long press gesture by a secondary button has been
   /// recognized.
   ///
   /// See also:
   ///
   ///  * [kSecondaryButton], the button this callback responds to.
   ///  * [onSecondaryLongPressStart], which has the same timing but has data for
   ///    the press location.
   GestureLongPressCallback? onSecondaryLongPress;

   /// Called when a long press gesture by a secondary button has been recognized.
   ///
   /// See also:
   ///
   ///  * [kSecondaryButton], the button this callback responds to.
   ///  * [onSecondaryLongPress], which has the same timing but without details.
   ///  * [LongPressStartDetails], which is passed as an argument to this
   ///    callback.
   GestureLongPressStartCallback? onSecondaryLongPressStart;

   /// Called when moving after the long press by a secondary button is
   /// recognized.
   ///
   /// See also:
   ///
   ///  * [kSecondaryButton], the button this callback responds to.
   ///  * [LongPressMoveUpdateDetails], which is passed as an argument to this
   ///    callback.
   GestureLongPressMoveUpdateCallback? onSecondaryLongPressMoveUpdate;

   /// Called when the pointer stops contacting the screen after a long-press by
   /// a secondary button.
   ///
   /// See also:
   ///
   ///  * [kSecondaryButton], the button this callback responds to.
   ///  * [onSecondaryLongPressEnd], which has the same timing but has data for
   ///    the up gesture location.
   GestureLongPressUpCallback? onSecondaryLongPressUp;

   /// Called when the pointer stops contacting the screen after a long-press by
   /// a secondary button.
   ///
   /// See also:
   ///
   ///  * [kSecondaryButton], the button this callback responds to.
   ///  * [onSecondaryLongPressUp], which has the same timing, but without
   ///    details.
   ///  * [LongPressEndDetails], which is passed as an argument to this callback.
   GestureLongPressEndCallback? onSecondaryLongPressEnd;

   /// Called when a long press gesture by a tertiary button has been
   /// recognized.
   ///
   /// See also:
   ///
   ///  * [kTertiaryButton], the button this callback responds to.
   ///  * [onTertiaryLongPressStart], which has the same timing but has data for
   ///    the press location.
   GestureLongPressCallback? onTertiaryLongPress;

   /// Called when a long press gesture by a tertiary button has been recognized.
   ///
   /// See also:
   ///
   ///  * [kTertiaryButton], the button this callback responds to.
   ///  * [onTertiaryLongPress], which has the same timing but without details.
   ///  * [LongPressStartDetails], which is passed as an argument to this
   ///    callback.
   GestureLongPressStartCallback? onTertiaryLongPressStart;

   /// Called when moving after the long press by a tertiary button is
   /// recognized.
   ///
   /// See also:
   ///
   ///  * [kTertiaryButton], the button this callback responds to.
   ///  * [LongPressMoveUpdateDetails], which is passed as an argument to this
   ///    callback.
   GestureLongPressMoveUpdateCallback? onTertiaryLongPressMoveUpdate;

   /// Called when the pointer stops contacting the screen after a long-press by
   /// a tertiary button.
   ///
   /// See also:
   ///
   ///  * [kTertiaryButton], the button this callback responds to.
   ///  * [onTertiaryLongPressEnd], which has the same timing but has data for
   ///    the up gesture location.
   GestureLongPressUpCallback? onTertiaryLongPressUp;

   /// Called when the pointer stops contacting the screen after a long-press by
   /// a tertiary button.
   ///
   /// See also:
   ///
   ///  * [kTertiaryButton], the button this callback responds to.
   ///  * [onTertiaryLongPressUp], which has the same timing, but without
   ///    details.
   ///  * [LongPressEndDetails], which is passed as an argument to this callback.
   GestureLongPressEndCallback? onTertiaryLongPressEnd;

   VelocityTracker? _velocityTracker;

   @override
   bool isPointerAllowed(PointerDownEvent event) {
     switch (event.buttons) {
       case kPrimaryButton:
         if (onLongPressStart == null &&
             onLongPress == null &&
             onLongPressMoveUpdate == null &&
             onLongPressEnd == null &&
             onLongPressUp == null)
           return false;
         break;
       case kSecondaryButton:
         if (onSecondaryLongPressStart == null &&
             onSecondaryLongPress == null &&
             onSecondaryLongPressMoveUpdate == null &&
             onSecondaryLongPressEnd == null &&
             onSecondaryLongPressUp == null)
           return false;
         break;
       case kTertiaryButton:
         if (onTertiaryLongPressStart == null &&
             onTertiaryLongPress == null &&
             onTertiaryLongPressMoveUpdate == null &&
             onTertiaryLongPressEnd == null &&
             onTertiaryLongPressUp == null)
           return false;
         break;
       default:
         return false;
     }
     return super.isPointerAllowed(event);
   }

   @override
   void didExceedDeadline() {
     // Exceeding the deadline puts the gesture in the accepted state.
     resolve(GestureDisposition.accepted);
     _longPressAccepted = true;
     super.acceptGesture(primaryPointer!);
     _checkLongPressStart();
   }

   @override
   void handlePrimaryPointer(PointerEvent event) {
     if (!event.synthesized) {
       if (event is PointerDownEvent) {
         _velocityTracker = VelocityTracker.withKind(event.kind);
         _velocityTracker!.addPosition(event.timeStamp, event.localPosition);
       }
       if (event is PointerMoveEvent) {
         assert(_velocityTracker != null);
         _velocityTracker!.addPosition(event.timeStamp, event.localPosition);
       }
     }

     if (event is PointerUpEvent) {
       if (_longPressAccepted == true) {
         _checkLongPressEnd(event);
       } else {
         // Pointer is lifted before timeout.
         resolve(GestureDisposition.rejected);
       }
       _reset();
     } else if (event is PointerCancelEvent) {
       _reset();
     } else if (event is PointerDownEvent) {
       // The first touch.
       _longPressOrigin = OffsetPair.fromEventPosition(event);
       _initialButtons = event.buttons;
     } else if (event is PointerMoveEvent) {
       if (event.buttons != _initialButtons) {
         resolve(GestureDisposition.rejected);
         stopTrackingPointer(primaryPointer!);
       } else if (_longPressAccepted) {
         _checkLongPressMoveUpdate(event);
       }
     }
   }

   void _checkLongPressStart() {
     switch (_initialButtons) {
       case kPrimaryButton:
         if (onLongPressStart != null) {
           final LongPressStartDetails details = LongPressStartDetails(
             globalPosition: _longPressOrigin!.global,
             localPosition: _longPressOrigin!.local,
           );
           invokeCallback<void>('onLongPressStart', () => onLongPressStart!(details));
         }
         if (onLongPress != null) {
           invokeCallback<void>('onLongPress', onLongPress!);
         }
         break;
       case kSecondaryButton:
         if (onSecondaryLongPressStart != null) {
           final LongPressStartDetails details = LongPressStartDetails(
             globalPosition: _longPressOrigin!.global,
             localPosition: _longPressOrigin!.local,
           );
           invokeCallback<void>(
               'onSecondaryLongPressStart', () => onSecondaryLongPressStart!(details));
         }
         if (onSecondaryLongPress != null) {
           invokeCallback<void>('onSecondaryLongPress', onSecondaryLongPress!);
         }
         break;
       case kTertiaryButton:
         if (onTertiaryLongPressStart != null) {
           final LongPressStartDetails details = LongPressStartDetails(
             globalPosition: _longPressOrigin!.global,
             localPosition: _longPressOrigin!.local,
           );
           invokeCallback<void>(
               'onTertiaryLongPressStart', () => onTertiaryLongPressStart!(details));
         }
         if (onTertiaryLongPress != null) {
           invokeCallback<void>('onTertiaryLongPress', onTertiaryLongPress!);
         }
         break;
       default:
         assert(false, 'Unhandled button $_initialButtons');
     }
   }

   void _checkLongPressMoveUpdate(PointerEvent event) {
     final LongPressMoveUpdateDetails details = LongPressMoveUpdateDetails(
       globalPosition: event.position,
       localPosition: event.localPosition,
       offsetFromOrigin: event.position - _longPressOrigin!.global,
       localOffsetFromOrigin: event.localPosition - _longPressOrigin!.local,
     );
     switch (_initialButtons) {
       case kPrimaryButton:
         if (onLongPressMoveUpdate != null) {
           invokeCallback<void>('onLongPressMoveUpdate',
             () => onLongPressMoveUpdate!(details));
         }
         break;
       case kSecondaryButton:
         if (onSecondaryLongPressMoveUpdate != null) {
           invokeCallback<void>('onSecondaryLongPressMoveUpdate',
             () => onSecondaryLongPressMoveUpdate!(details));
         }
         break;
       case kTertiaryButton:
         if (onTertiaryLongPressMoveUpdate != null) {
           invokeCallback<void>('onTertiaryLongPressMoveUpdate',
                   () => onTertiaryLongPressMoveUpdate!(details));
         }
         break;
       default:
         assert(false, 'Unhandled button $_initialButtons');
     }
   }

   void _checkLongPressEnd(PointerEvent event) {
     final VelocityEstimate? estimate = _velocityTracker!.getVelocityEstimate();
     final Velocity velocity = estimate == null
         ? Velocity.zero
         : Velocity(pixelsPerSecond: estimate.pixelsPerSecond);
     final LongPressEndDetails details = LongPressEndDetails(
       globalPosition: event.position,
       localPosition: event.localPosition,
       velocity: velocity,
     );

     _velocityTracker = null;
     switch (_initialButtons) {
       case kPrimaryButton:
         if (onLongPressEnd != null) {
           invokeCallback<void>('onLongPressEnd', () => onLongPressEnd!(details));
         }
         if (onLongPressUp != null) {
           invokeCallback<void>('onLongPressUp', onLongPressUp!);
         }
         break;
       case kSecondaryButton:
         if (onSecondaryLongPressEnd != null) {
           invokeCallback<void>('onSecondaryLongPressEnd', () => onSecondaryLongPressEnd!(details));
         }
         if (onSecondaryLongPressUp != null) {
           invokeCallback<void>('onSecondaryLongPressUp', onSecondaryLongPressUp!);
         }
         break;
       case kTertiaryButton:
         if (onTertiaryLongPressEnd != null) {
           invokeCallback<void>('onTertiaryLongPressEnd', () => onTertiaryLongPressEnd!(details));
         }
         if (onTertiaryLongPressUp != null) {
           invokeCallback<void>('onTertiaryLongPressUp', onTertiaryLongPressUp!);
         }
         break;
       default:
         assert(false, 'Unhandled button $_initialButtons');
     }
   }

   void _reset() {
     _longPressAccepted = false;
     _longPressOrigin = null;
     _initialButtons = null;
     _velocityTracker = null;
   }

   @override
   void resolve(GestureDisposition disposition) {
     if (_longPressAccepted && disposition == GestureDisposition.rejected) {
       // This can happen if the gesture has been canceled. For example when
       // the buttons have changed.
       _reset();
     }
     super.resolve(disposition);
   }

   @override
   void acceptGesture(int pointer) {
     // Winning the arena isn't important here since it may happen from a sweep.
     // Explicitly exceeding the deadline puts the gesture in accepted state.
   }

   @override
   String get debugDescription => 'long press';
 }
	// 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 'arena.dart';
	import 'constants.dart';
	import 'events.dart';
	import 'recognizer.dart';
	import 'velocity_tracker.dart';

	/// Callback signature for [LongPressGestureRecognizer.onLongPress].
	///
	/// Called when a pointer has remained in contact with the screen at the
	/// same location for a long period of time.
	typedef GestureLongPressCallback = void Function();

	/// Callback signature for [LongPressGestureRecognizer.onLongPressUp].
	///
	/// Called when a pointer stops contacting the screen after a long press
	/// gesture was detected.
	typedef GestureLongPressUpCallback = void Function();

	/// Callback signature for [LongPressGestureRecognizer.onLongPressStart].
	///
	/// Called when a pointer has remained in contact with the screen at the
	/// same location for a long period of time. Also reports the long press down
	/// position.
	typedef GestureLongPressStartCallback = void Function(LongPressStartDetails details);

	/// Callback signature for [LongPressGestureRecognizer.onLongPressMoveUpdate].
	///
	/// Called when a pointer is moving after being held in contact at the same
	/// location for a long period of time. Reports the new position and its offset
	/// from the original down position.
	typedef GestureLongPressMoveUpdateCallback = void Function(LongPressMoveUpdateDetails details);

	/// Callback signature for [LongPressGestureRecognizer.onLongPressEnd].
	///
	/// Called when a pointer stops contacting the screen after a long press
	/// gesture was detected. Also reports the position where the pointer stopped
	/// contacting the screen.
	typedef GestureLongPressEndCallback = void Function(LongPressEndDetails details);

	/// Details for callbacks that use [GestureLongPressStartCallback].
	///
	/// See also:
	///
	/// * [LongPressGestureRecognizer.onLongPressStart], which uses [GestureLongPressStartCallback].
	/// * [LongPressMoveUpdateDetails], the details for [GestureLongPressMoveUpdateCallback]
	/// * [LongPressEndDetails], the details for [GestureLongPressEndCallback].
	class LongPressStartDetails {
	/// Creates the details for a [GestureLongPressStartCallback].
	///
	/// The [globalPosition] argument must not be null.
	const LongPressStartDetails({
	this.globalPosition = Offset.zero,
	Offset? localPosition,
	}) : assert(globalPosition != null),
	localPosition = localPosition ?? globalPosition;

	/// The global position at which the pointer contacted the screen.
	final Offset globalPosition;

	/// The local position at which the pointer contacted the screen.
	final Offset localPosition;
	}

	/// Details for callbacks that use [GestureLongPressMoveUpdateCallback].
	///
	/// See also:
	///
	/// * [LongPressGestureRecognizer.onLongPressMoveUpdate], which uses [GestureLongPressMoveUpdateCallback].
	/// * [LongPressEndDetails], the details for [GestureLongPressEndCallback]
	/// * [LongPressStartDetails], the details for [GestureLongPressStartCallback].
	class LongPressMoveUpdateDetails {
	/// Creates the details for a [GestureLongPressMoveUpdateCallback].
	///
	/// The [globalPosition] and [offsetFromOrigin] arguments must not be null.
	const LongPressMoveUpdateDetails({
	this.globalPosition = Offset.zero,
	Offset? localPosition,
	this.offsetFromOrigin = Offset.zero,
	Offset? localOffsetFromOrigin,
	}) : assert(globalPosition != null),
	assert(offsetFromOrigin != null),
	localPosition = localPosition ?? globalPosition,
	localOffsetFromOrigin = localOffsetFromOrigin ?? offsetFromOrigin;

	/// The global position of the pointer when it triggered this update.
	final Offset globalPosition;

	/// The local position of the pointer when it triggered this update.
	final Offset localPosition;

	/// A delta offset from the point where the long press drag initially contacted
	/// the screen to the point where the pointer is currently located (the
	/// present [globalPosition]) when this callback is triggered.
	final Offset offsetFromOrigin;

	/// A local delta offset from the point where the long press drag initially contacted
	/// the screen to the point where the pointer is currently located (the
	/// present [localPosition]) when this callback is triggered.
	final Offset localOffsetFromOrigin;
	}

	/// Details for callbacks that use [GestureLongPressEndCallback].
	///
	/// See also:
	///
	/// * [LongPressGestureRecognizer.onLongPressEnd], which uses [GestureLongPressEndCallback].
	/// * [LongPressMoveUpdateDetails], the details for [GestureLongPressMoveUpdateCallback]
	/// * [LongPressStartDetails], the details for [GestureLongPressStartCallback].
	class LongPressEndDetails {
	/// Creates the details for a [GestureLongPressEndCallback].
	///
	/// The [globalPosition] argument must not be null.
	const LongPressEndDetails({
	this.globalPosition = Offset.zero,
	Offset? localPosition,
	this.velocity = Velocity.zero,
	}) : assert(globalPosition != null),
	localPosition = localPosition ?? globalPosition;

	/// The global position at which the pointer lifted from the screen.
	final Offset globalPosition;

	/// The local position at which the pointer contacted the screen.
	final Offset localPosition;

	/// The pointer's velocity when it stopped contacting the screen.
	///
	/// Defaults to zero if not specified in the constructor.
	final Velocity velocity;
	}

	/// Recognizes when the user has pressed down at the same location for a long
	/// period of time.
	///
	/// The gesture must not deviate in position from its touch down point for 500ms
	/// until it's recognized. Once the gesture is accepted, the finger can be
	/// moved, triggering [onLongPressMoveUpdate] callbacks, unless the
	/// [postAcceptSlopTolerance] constructor argument is specified.
	///
	/// [LongPressGestureRecognizer] may compete on pointer events of
	/// [kPrimaryButton], [kSecondaryButton], and/or [kTertiaryButton] if at least
	/// one corresponding callback is non-null. If it has no callbacks, it is a no-op.
	class LongPressGestureRecognizer extends PrimaryPointerGestureRecognizer {
	/// Creates a long-press gesture recognizer.
	///
	/// Consider assigning the [onLongPressStart] callback after creating this
	/// object.
	///
	/// The [postAcceptSlopTolerance] argument can be used to specify a maximum
	/// allowed distance for the gesture to deviate from the starting point once
	/// the long press has triggered. If the gesture deviates past that point,
	/// subsequent callbacks ([onLongPressMoveUpdate], [onLongPressUp],
	/// [onLongPressEnd]) will stop. Defaults to null, which means the gesture
	/// can be moved without limit once the long press is accepted.
	///
	/// The [duration] argument can be used to overwrite the default duration
	/// after which the long press will be recognized.
	LongPressGestureRecognizer({
	Duration? duration,
	double? postAcceptSlopTolerance,
	PointerDeviceKind? kind,
	Object? debugOwner,
	}) : super(
	deadline: duration ?? kLongPressTimeout,
	postAcceptSlopTolerance: postAcceptSlopTolerance,
	kind: kind,
	debugOwner: debugOwner,
	);

	bool _longPressAccepted = false;
	OffsetPair? _longPressOrigin;
	// The buttons sent by `PointerDownEvent`. If a `PointerMoveEvent` comes with a
	// different set of buttons, the gesture is canceled.
	int? _initialButtons;

	/// Called when a long press gesture by a primary button has been recognized.
	///
	/// See also:
	///
	/// * [kPrimaryButton], the button this callback responds to.
	/// * [onLongPressStart], which has the same timing but has data for the
	/// press location.
	GestureLongPressCallback? onLongPress;

	/// Called when a long press gesture by a primary button has been recognized.
	///
	/// See also:
	///
	/// * [kPrimaryButton], the button this callback responds to.
	/// * [onLongPress], which has the same timing but without details.
	/// * [LongPressStartDetails], which is passed as an argument to this callback.
	GestureLongPressStartCallback? onLongPressStart;

	/// Called when moving after the long press by a primary button is recognized.
	///
	/// See also:
	///
	/// * [kPrimaryButton], the button this callback responds to.
	/// * [LongPressMoveUpdateDetails], which is passed as an argument to this
	/// callback.
	GestureLongPressMoveUpdateCallback? onLongPressMoveUpdate;

	/// Called when the pointer stops contacting the screen after a long-press
	/// by a primary button.
	///
	/// See also:
	///
	/// * [kPrimaryButton], the button this callback responds to.
	/// * [onLongPressEnd], which has the same timing but has data for the up
	/// gesture location.
	GestureLongPressUpCallback? onLongPressUp;

	/// Called when the pointer stops contacting the screen after a long-press
	/// by a primary button.
	///
	/// See also:
	///
	/// * [kPrimaryButton], the button this callback responds to.
	/// * [onLongPressUp], which has the same timing, but without details.
	/// * [LongPressEndDetails], which is passed as an argument to this
	/// callback.
	GestureLongPressEndCallback? onLongPressEnd;

	/// Called when a long press gesture by a secondary button has been
	/// recognized.
	///
	/// See also:
	///
	/// * [kSecondaryButton], the button this callback responds to.
	/// * [onSecondaryLongPressStart], which has the same timing but has data for
	/// the press location.
	GestureLongPressCallback? onSecondaryLongPress;

	/// Called when a long press gesture by a secondary button has been recognized.
	///
	/// See also:
	///
	/// * [kSecondaryButton], the button this callback responds to.
	/// * [onSecondaryLongPress], which has the same timing but without details.
	/// * [LongPressStartDetails], which is passed as an argument to this
	/// callback.
	GestureLongPressStartCallback? onSecondaryLongPressStart;

	/// Called when moving after the long press by a secondary button is
	/// recognized.
	///
	/// See also:
	///
	/// * [kSecondaryButton], the button this callback responds to.
	/// * [LongPressMoveUpdateDetails], which is passed as an argument to this
	/// callback.
	GestureLongPressMoveUpdateCallback? onSecondaryLongPressMoveUpdate;

	/// Called when the pointer stops contacting the screen after a long-press by
	/// a secondary button.
	///
	/// See also:
	///
	/// * [kSecondaryButton], the button this callback responds to.
	/// * [onSecondaryLongPressEnd], which has the same timing but has data for
	/// the up gesture location.
	GestureLongPressUpCallback? onSecondaryLongPressUp;

	/// Called when the pointer stops contacting the screen after a long-press by
	/// a secondary button.
	///
	/// See also:
	///
	/// * [kSecondaryButton], the button this callback responds to.
	/// * [onSecondaryLongPressUp], which has the same timing, but without
	/// details.
	/// * [LongPressEndDetails], which is passed as an argument to this callback.
	GestureLongPressEndCallback? onSecondaryLongPressEnd;

	/// Called when a long press gesture by a tertiary button has been
	/// recognized.
	///
	/// See also:
	///
	/// * [kTertiaryButton], the button this callback responds to.
	/// * [onTertiaryLongPressStart], which has the same timing but has data for
	/// the press location.
	GestureLongPressCallback? onTertiaryLongPress;

	/// Called when a long press gesture by a tertiary button has been recognized.
	///
	/// See also:
	///
	/// * [kTertiaryButton], the button this callback responds to.
	/// * [onTertiaryLongPress], which has the same timing but without details.
	/// * [LongPressStartDetails], which is passed as an argument to this
	/// callback.
	GestureLongPressStartCallback? onTertiaryLongPressStart;

	/// Called when moving after the long press by a tertiary button is
	/// recognized.
	///
	/// See also:
	///
	/// * [kTertiaryButton], the button this callback responds to.
	/// * [LongPressMoveUpdateDetails], which is passed as an argument to this
	/// callback.
	GestureLongPressMoveUpdateCallback? onTertiaryLongPressMoveUpdate;

	/// Called when the pointer stops contacting the screen after a long-press by
	/// a tertiary button.
	///
	/// See also:
	///
	/// * [kTertiaryButton], the button this callback responds to.
	/// * [onTertiaryLongPressEnd], which has the same timing but has data for
	/// the up gesture location.
	GestureLongPressUpCallback? onTertiaryLongPressUp;

	/// Called when the pointer stops contacting the screen after a long-press by
	/// a tertiary button.
	///
	/// See also:
	///
	/// * [kTertiaryButton], the button this callback responds to.
	/// * [onTertiaryLongPressUp], which has the same timing, but without
	/// details.
	/// * [LongPressEndDetails], which is passed as an argument to this callback.
	GestureLongPressEndCallback? onTertiaryLongPressEnd;

	VelocityTracker? _velocityTracker;

	@override
	bool isPointerAllowed(PointerDownEvent event) {
	switch (event.buttons) {
	case kPrimaryButton:
	if (onLongPressStart == null &&
	onLongPress == null &&
	onLongPressMoveUpdate == null &&
	onLongPressEnd == null &&
	onLongPressUp == null)
	return false;
	break;
	case kSecondaryButton:
	if (onSecondaryLongPressStart == null &&
	onSecondaryLongPress == null &&
	onSecondaryLongPressMoveUpdate == null &&
	onSecondaryLongPressEnd == null &&
	onSecondaryLongPressUp == null)
	return false;
	break;
	case kTertiaryButton:
	if (onTertiaryLongPressStart == null &&
	onTertiaryLongPress == null &&
	onTertiaryLongPressMoveUpdate == null &&
	onTertiaryLongPressEnd == null &&
	onTertiaryLongPressUp == null)
	return false;
	break;
	default:
	return false;
	}
	return super.isPointerAllowed(event);
	}

	@override
	void didExceedDeadline() {
	// Exceeding the deadline puts the gesture in the accepted state.
	resolve(GestureDisposition.accepted);
	_longPressAccepted = true;
	super.acceptGesture(primaryPointer!);
	_checkLongPressStart();
	}

	@override
	void handlePrimaryPointer(PointerEvent event) {
	if (!event.synthesized) {
	if (event is PointerDownEvent) {
	_velocityTracker = VelocityTracker.withKind(event.kind);
	_velocityTracker!.addPosition(event.timeStamp, event.localPosition);
	}
	if (event is PointerMoveEvent) {
	assert(_velocityTracker != null);
	_velocityTracker!.addPosition(event.timeStamp, event.localPosition);
	}
	}

	if (event is PointerUpEvent) {
	if (_longPressAccepted == true) {
	_checkLongPressEnd(event);
	} else {
	// Pointer is lifted before timeout.
	resolve(GestureDisposition.rejected);
	}
	_reset();
	} else if (event is PointerCancelEvent) {
	_reset();
	} else if (event is PointerDownEvent) {
	// The first touch.
	_longPressOrigin = OffsetPair.fromEventPosition(event);
	_initialButtons = event.buttons;
	} else if (event is PointerMoveEvent) {
	if (event.buttons != _initialButtons) {
	resolve(GestureDisposition.rejected);
	stopTrackingPointer(primaryPointer!);
	} else if (_longPressAccepted) {
	_checkLongPressMoveUpdate(event);
	}
	}
	}

	void _checkLongPressStart() {
	switch (_initialButtons) {
	case kPrimaryButton:
	if (onLongPressStart != null) {
	final LongPressStartDetails details = LongPressStartDetails(
	globalPosition: _longPressOrigin!.global,
	localPosition: _longPressOrigin!.local,
	);
	invokeCallback<void>('onLongPressStart', () => onLongPressStart!(details));
	}
	if (onLongPress != null) {
	invokeCallback<void>('onLongPress', onLongPress!);
	}
	break;
	case kSecondaryButton:
	if (onSecondaryLongPressStart != null) {
	final LongPressStartDetails details = LongPressStartDetails(
	globalPosition: _longPressOrigin!.global,
	localPosition: _longPressOrigin!.local,
	);
	invokeCallback<void>(
	'onSecondaryLongPressStart', () => onSecondaryLongPressStart!(details));
	}
	if (onSecondaryLongPress != null) {
	invokeCallback<void>('onSecondaryLongPress', onSecondaryLongPress!);
	}
	break;
	case kTertiaryButton:
	if (onTertiaryLongPressStart != null) {
	final LongPressStartDetails details = LongPressStartDetails(
	globalPosition: _longPressOrigin!.global,
	localPosition: _longPressOrigin!.local,
	);
	invokeCallback<void>(
	'onTertiaryLongPressStart', () => onTertiaryLongPressStart!(details));
	}
	if (onTertiaryLongPress != null) {
	invokeCallback<void>('onTertiaryLongPress', onTertiaryLongPress!);
	}
	break;
	default:
	assert(false, 'Unhandled button $_initialButtons');
	}
	}

	void _checkLongPressMoveUpdate(PointerEvent event) {
	final LongPressMoveUpdateDetails details = LongPressMoveUpdateDetails(
	globalPosition: event.position,
	localPosition: event.localPosition,
	offsetFromOrigin: event.position - _longPressOrigin!.global,
	localOffsetFromOrigin: event.localPosition - _longPressOrigin!.local,
	);
	switch (_initialButtons) {
	case kPrimaryButton:
	if (onLongPressMoveUpdate != null) {
	invokeCallback<void>('onLongPressMoveUpdate',
	() => onLongPressMoveUpdate!(details));
	}
	break;
	case kSecondaryButton:
	if (onSecondaryLongPressMoveUpdate != null) {
	invokeCallback<void>('onSecondaryLongPressMoveUpdate',
	() => onSecondaryLongPressMoveUpdate!(details));
	}
	break;
	case kTertiaryButton:
	if (onTertiaryLongPressMoveUpdate != null) {
	invokeCallback<void>('onTertiaryLongPressMoveUpdate',
	() => onTertiaryLongPressMoveUpdate!(details));
	}
	break;
	default:
	assert(false, 'Unhandled button $_initialButtons');
	}
	}

	void _checkLongPressEnd(PointerEvent event) {
	final VelocityEstimate? estimate = _velocityTracker!.getVelocityEstimate();
	final Velocity velocity = estimate == null
	? Velocity.zero
	: Velocity(pixelsPerSecond: estimate.pixelsPerSecond);
	final LongPressEndDetails details = LongPressEndDetails(
	globalPosition: event.position,
	localPosition: event.localPosition,
	velocity: velocity,
	);

	_velocityTracker = null;
	switch (_initialButtons) {
	case kPrimaryButton:
	if (onLongPressEnd != null) {
	invokeCallback<void>('onLongPressEnd', () => onLongPressEnd!(details));
	}
	if (onLongPressUp != null) {
	invokeCallback<void>('onLongPressUp', onLongPressUp!);
	}
	break;
	case kSecondaryButton:
	if (onSecondaryLongPressEnd != null) {
	invokeCallback<void>('onSecondaryLongPressEnd', () => onSecondaryLongPressEnd!(details));
	}
	if (onSecondaryLongPressUp != null) {
	invokeCallback<void>('onSecondaryLongPressUp', onSecondaryLongPressUp!);
	}
	break;
	case kTertiaryButton:
	if (onTertiaryLongPressEnd != null) {
	invokeCallback<void>('onTertiaryLongPressEnd', () => onTertiaryLongPressEnd!(details));
	}
	if (onTertiaryLongPressUp != null) {
	invokeCallback<void>('onTertiaryLongPressUp', onTertiaryLongPressUp!);
	}
	break;
	default:
	assert(false, 'Unhandled button $_initialButtons');
	}
	}

	void _reset() {
	_longPressAccepted = false;
	_longPressOrigin = null;
	_initialButtons = null;
	_velocityTracker = null;
	}

	@override
	void resolve(GestureDisposition disposition) {
	if (_longPressAccepted && disposition == GestureDisposition.rejected) {
	// This can happen if the gesture has been canceled. For example when
	// the buttons have changed.
	_reset();
	}
	super.resolve(disposition);
	}

	@override
	void acceptGesture(int pointer) {
	// Winning the arena isn't important here since it may happen from a sweep.
	// Explicitly exceeding the deadline puts the gesture in accepted state.
	}

	@override
	String get debugDescription => 'long press';
	}