packages/flutter/lib/src/gestures/force_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 'dart:ui' show Offset;

 import 'package:flutter/foundation.dart';

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

 enum _ForceState {
   // No pointer has touched down and the detector is ready for a pointer down to occur.
   ready,

   // A pointer has touched down, but a force press gesture has not yet been detected.
   possible,

   // A pointer is down and a force press gesture has been detected. However, if
   // the ForcePressGestureRecognizer is the only recognizer in the arena, thus
   // accepted as soon as the gesture state is possible, the gesture will not
   // yet have started.
   accepted,

   // A pointer is down and the gesture has started, ie. the pressure of the pointer
   // has just become greater than the ForcePressGestureRecognizer.startPressure.
   started,

   // A pointer is down and the pressure of the pointer has just become greater
   // than the ForcePressGestureRecognizer.peakPressure. Even after a pointer
   // crosses this threshold, onUpdate callbacks will still be sent.
   peaked,
 }

 /// Details object for callbacks that use [GestureForcePressStartCallback],
 /// [GestureForcePressPeakCallback], [GestureForcePressEndCallback] or
 /// [GestureForcePressUpdateCallback].
 ///
 /// See also:
 ///
 ///  * [ForcePressGestureRecognizer.onStart], [ForcePressGestureRecognizer.onPeak],
 ///    [ForcePressGestureRecognizer.onEnd], and [ForcePressGestureRecognizer.onUpdate]
 ///    which use [ForcePressDetails].
 class ForcePressDetails {
   /// Creates details for a [GestureForcePressStartCallback],
   /// [GestureForcePressPeakCallback] or [GestureForcePressEndCallback].
   ///
   /// The [globalPosition] argument must not be null.
   ForcePressDetails({
     @required this.globalPosition,
     Offset localPosition,
     @required this.pressure,
   }) : assert(globalPosition != null),
        assert(pressure != null),
        localPosition = localPosition ?? globalPosition;

   /// The global position at which the function was called.
   final Offset globalPosition;

   /// The local position at which the function was called.
   final Offset localPosition;

   /// The pressure of the pointer on the screen.
   final double pressure;
 }

 /// Signature used by a [ForcePressGestureRecognizer] for when a pointer has
 /// pressed with at least [ForcePressGestureRecognizer.startPressure].
 typedef GestureForcePressStartCallback = void Function(ForcePressDetails details);

 /// Signature used by [ForcePressGestureRecognizer] for when a pointer that has
 /// pressed with at least [ForcePressGestureRecognizer.peakPressure].
 typedef GestureForcePressPeakCallback = void Function(ForcePressDetails details);

 /// Signature used by [ForcePressGestureRecognizer] during the frames
 /// after the triggering of a [ForcePressGestureRecognizer.onStart] callback.
 typedef GestureForcePressUpdateCallback = void Function(ForcePressDetails details);

 /// Signature for when the pointer that previously triggered a
 /// [ForcePressGestureRecognizer.onStart] callback is no longer in contact
 /// with the screen.
 typedef GestureForcePressEndCallback = void Function(ForcePressDetails details);

 /// Signature used by [ForcePressGestureRecognizer] for interpolating the raw
 /// device pressure to a value in the range [0, 1] given the device's pressure
 /// min and pressure max.
 typedef GestureForceInterpolation = double Function(double pressureMin, double pressureMax, double pressure);

 /// Recognizes a force press on devices that have force sensors.
 ///
 /// Only the force from a single pointer is used to invoke events. A tap
 /// recognizer will win against this recognizer on pointer up as long as the
 /// pointer has not pressed with a force greater than
 /// [ForcePressGestureRecognizer.startPressure]. A long press recognizer will
 /// win when the press down time exceeds the threshold time as long as the
 /// pointer's pressure was never greater than
 /// [ForcePressGestureRecognizer.startPressure] in that duration.
 ///
 /// As of November, 2018 iPhone devices of generation 6S and higher have
 /// force touch functionality, with the exception of the iPhone XR. In addition,
 /// a small handful of Android devices have this functionality as well.
 ///
 /// Devices with faux screen pressure sensors like the Pixel 2 and 3 will not
 /// send any force press related callbacks.
 ///
 /// Reported pressure will always be in the range 0.0 to 1.0, where 1.0 is
 /// maximum pressure and 0.0 is minimum pressure. If using a custom
 /// [interpolation] callback, the pressure reported will correspond to that
 /// custom curve.
 class ForcePressGestureRecognizer extends OneSequenceGestureRecognizer {
   /// Creates a force press gesture recognizer.
   ///
   /// The [startPressure] defaults to 0.4, and [peakPressure] defaults to 0.85
   /// where a value of 0.0 is no pressure and a value of 1.0 is maximum pressure.
   ///
   /// The [startPressure], [peakPressure] and [interpolation] arguments must not
   /// be null. The [peakPressure] argument must be greater than [startPressure].
   /// 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, 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
   /// detectors, only the force press gesture will be detected and all others
   /// will be rejected.
   ///
   /// The position of the pointer is provided in the callback's `details`
   /// argument, which is a [ForcePressDetails] object.
   GestureForcePressStartCallback onStart;

   /// A pointer is in contact with the screen and is either moving on the plane
   /// of the screen, pressing the screen with varying forces or both
   /// simultaneously.
   ///
   /// This callback will be invoked for every pointer event after the invocation
   /// of [onStart] and/or [onPeak] and before the invocation of [onEnd], no
   /// matter what the pressure is during this time period. The position and
   /// pressure of the pointer is provided in the callback's `details` argument,
   /// which is a [ForcePressDetails] object.
   GestureForcePressUpdateCallback onUpdate;

   /// A pointer is in contact with the screen and has just pressed with a force
   /// exceeding the [peakPressure]. This is an arbitrary second level action
   /// threshold and isn't necessarily the maximum possible device pressure
   /// (which is 1.0).
   ///
   /// The position of the pointer is provided in the callback's `details`
   /// argument, which is a [ForcePressDetails] object.
   GestureForcePressPeakCallback onPeak;

   /// A pointer is no longer in contact with the screen.
   ///
   /// The position of the pointer is provided in the callback's `details`
   /// argument, which is a [ForcePressDetails] object.
   GestureForcePressEndCallback onEnd;

   /// The pressure of the press required to initiate a force press.
   ///
   /// A value of 0.0 is no pressure, and 1.0 is maximum pressure.
   final double startPressure;

   /// The pressure of the press required to peak a force press.
   ///
   /// A value of 0.0 is no pressure, and 1.0 is maximum pressure. This value
   /// must be greater than [startPressure].
   final double peakPressure;

   /// The function used to convert the raw device pressure values into a value
   /// in the range 0.0 to 1.0.
   ///
   /// The function takes in the device's minimum, maximum and raw touch pressure
   /// and returns a value in the range 0.0 to 1.0 denoting the interpolated
   /// touch pressure.
   ///
   /// This function must always return values in the range 0.0 to 1.0 given a
   /// pressure that is between the minimum and maximum pressures. It may return
   /// `double.NaN` for values that it does not want to support.
   ///
   /// By default, the function is a linear interpolation; however, changing the
   /// function could be useful to accommodate variations in the way different
   /// devices respond to pressure, or to change how animations from pressure
   /// feedback are rendered.
   ///
   /// For example, an ease-in curve can be used to determine the interpolated
   /// value:
   ///
   /// ```dart
   /// static double interpolateWithEasing(double min, double max, double t) {
   ///    final double lerp = (t - min) / (max - min);
   ///    return Curves.easeIn.transform(lerp);
   /// }
   /// ```
   final GestureForceInterpolation interpolation;

   OffsetPair _lastPosition;
   double _lastPressure;
   _ForceState _state = _ForceState.ready;

   @override
   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.
     if (event is! PointerUpEvent && event.pressureMax <= 1.0) {
       resolve(GestureDisposition.rejected);
     } else {
       startTrackingPointer(event.pointer, event.transform);
       if (_state == _ForceState.ready) {
         _state = _ForceState.possible;
         _lastPosition = OffsetPair.fromEventPosition(event);
       }
     }
   }

   @override
   void handleEvent(PointerEvent event) {
     assert(_state != _ForceState.ready);
     // A static pointer with changes in pressure creates PointerMoveEvent events.
     if (event is PointerMoveEvent || event is PointerDownEvent) {
       if (event.pressure > event.pressureMax || event.pressure < event.pressureMin) {
         debugPrint(
           'The reported device pressure ' + event.pressure.toString() +
           ' is outside of the device pressure range where: ' +
           event.pressureMin.toString() + ' <= pressure <= ' + event.pressureMax.toString(),
         );
       }

       final double pressure = interpolation(event.pressureMin, event.pressureMax, event.pressure);
       assert(
         (pressure >= 0.0 && pressure <= 1.0) || // Interpolated pressure must be between 1.0 and 0.0...
         pressure.isNaN // and interpolation may return NaN for values it doesn't want to support...
       );

       _lastPosition = OffsetPair.fromEventPosition(event);
       _lastPressure = pressure;

       if (_state == _ForceState.possible) {
         if (pressure > startPressure) {
           _state = _ForceState.started;
           resolve(GestureDisposition.accepted);
         } else if (event.delta.distanceSquared > kTouchSlop) {
           resolve(GestureDisposition.rejected);
         }
       }
       // In case this is the only gesture detector we still don't want to start
       // the gesture until the pressure is greater than the startPressure.
       if (pressure > startPressure && _state == _ForceState.accepted) {
         _state = _ForceState.started;
         if (onStart != null) {
           invokeCallback<void>('onStart', () => onStart(ForcePressDetails(
             pressure: pressure,
             globalPosition: _lastPosition.global,
             localPosition: _lastPosition.local,
           )));
         }
       }
       if (onPeak != null && pressure > peakPressure &&
          (_state == _ForceState.started)) {
         _state = _ForceState.peaked;
         if (onPeak != null) {
           invokeCallback<void>('onPeak', () => onPeak(ForcePressDetails(
             pressure: pressure,
             globalPosition: event.position,
             localPosition: event.localPosition,
           )));
         }
       }
       if (onUpdate != null &&  !pressure.isNaN &&
          (_state == _ForceState.started || _state == _ForceState.peaked)) {
         if (onUpdate != null) {
           invokeCallback<void>('onUpdate', () => onUpdate(ForcePressDetails(
             pressure: pressure,
             globalPosition: event.position,
             localPosition: event.localPosition,
           )));
         }
       }
     }
     stopTrackingIfPointerNoLongerDown(event);
   }

   @override
   void acceptGesture(int pointer) {
     if (_state == _ForceState.possible)
       _state = _ForceState.accepted;

     if (onStart != null && _state == _ForceState.started) {
       invokeCallback<void>('onStart', () => onStart(ForcePressDetails(
         pressure: _lastPressure,
         globalPosition: _lastPosition.global,
         localPosition: _lastPosition.local,
       )));
     }
   }

   @override
   void didStopTrackingLastPointer(int pointer) {
     final bool wasAccepted = _state == _ForceState.started || _state == _ForceState.peaked;
     if (_state == _ForceState.possible) {
       resolve(GestureDisposition.rejected);
       return;
     }
     if (wasAccepted && onEnd != null) {
       if (onEnd != null) {
         invokeCallback<void>('onEnd', () => onEnd(ForcePressDetails(
           pressure: 0.0,
           globalPosition: _lastPosition.global,
           localPosition: _lastPosition.local,
         )));
       }
     }
     _state = _ForceState.ready;
   }

   @override
   void rejectGesture(int pointer) {
     stopTrackingPointer(pointer);
     didStopTrackingLastPointer(pointer);
   }

   static double _inverseLerp(double min, double max, double t) {
     assert(min <= max);
     double value = (t - min) / (max - min);

     // If the device incorrectly reports a pressure outside of pressureMin
     // and pressureMax, we still want this recognizer to respond normally.
     if (!value.isNaN)
       value = value.clamp(0.0, 1.0) as double;
     return value;
   }

   @override
   String get debugDescription => 'force 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 'dart:ui' show Offset;

	import 'package:flutter/foundation.dart';

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

	enum _ForceState {
	// No pointer has touched down and the detector is ready for a pointer down to occur.
	ready,

	// A pointer has touched down, but a force press gesture has not yet been detected.
	possible,

	// A pointer is down and a force press gesture has been detected. However, if
	// the ForcePressGestureRecognizer is the only recognizer in the arena, thus
	// accepted as soon as the gesture state is possible, the gesture will not
	// yet have started.
	accepted,

	// A pointer is down and the gesture has started, ie. the pressure of the pointer
	// has just become greater than the ForcePressGestureRecognizer.startPressure.
	started,

	// A pointer is down and the pressure of the pointer has just become greater
	// than the ForcePressGestureRecognizer.peakPressure. Even after a pointer
	// crosses this threshold, onUpdate callbacks will still be sent.
	peaked,
	}

	/// Details object for callbacks that use [GestureForcePressStartCallback],
	/// [GestureForcePressPeakCallback], [GestureForcePressEndCallback] or
	/// [GestureForcePressUpdateCallback].
	///
	/// See also:
	///
	/// * [ForcePressGestureRecognizer.onStart], [ForcePressGestureRecognizer.onPeak],
	/// [ForcePressGestureRecognizer.onEnd], and [ForcePressGestureRecognizer.onUpdate]
	/// which use [ForcePressDetails].
	class ForcePressDetails {
	/// Creates details for a [GestureForcePressStartCallback],
	/// [GestureForcePressPeakCallback] or [GestureForcePressEndCallback].
	///
	/// The [globalPosition] argument must not be null.
	ForcePressDetails({
	@required this.globalPosition,
	Offset localPosition,
	@required this.pressure,
	}) : assert(globalPosition != null),
	assert(pressure != null),
	localPosition = localPosition ?? globalPosition;

	/// The global position at which the function was called.
	final Offset globalPosition;

	/// The local position at which the function was called.
	final Offset localPosition;

	/// The pressure of the pointer on the screen.
	final double pressure;
	}

	/// Signature used by a [ForcePressGestureRecognizer] for when a pointer has
	/// pressed with at least [ForcePressGestureRecognizer.startPressure].
	typedef GestureForcePressStartCallback = void Function(ForcePressDetails details);

	/// Signature used by [ForcePressGestureRecognizer] for when a pointer that has
	/// pressed with at least [ForcePressGestureRecognizer.peakPressure].
	typedef GestureForcePressPeakCallback = void Function(ForcePressDetails details);

	/// Signature used by [ForcePressGestureRecognizer] during the frames
	/// after the triggering of a [ForcePressGestureRecognizer.onStart] callback.
	typedef GestureForcePressUpdateCallback = void Function(ForcePressDetails details);

	/// Signature for when the pointer that previously triggered a
	/// [ForcePressGestureRecognizer.onStart] callback is no longer in contact
	/// with the screen.
	typedef GestureForcePressEndCallback = void Function(ForcePressDetails details);

	/// Signature used by [ForcePressGestureRecognizer] for interpolating the raw
	/// device pressure to a value in the range [0, 1] given the device's pressure
	/// min and pressure max.
	typedef GestureForceInterpolation = double Function(double pressureMin, double pressureMax, double pressure);

	/// Recognizes a force press on devices that have force sensors.
	///
	/// Only the force from a single pointer is used to invoke events. A tap
	/// recognizer will win against this recognizer on pointer up as long as the
	/// pointer has not pressed with a force greater than
	/// [ForcePressGestureRecognizer.startPressure]. A long press recognizer will
	/// win when the press down time exceeds the threshold time as long as the
	/// pointer's pressure was never greater than
	/// [ForcePressGestureRecognizer.startPressure] in that duration.
	///
	/// As of November, 2018 iPhone devices of generation 6S and higher have
	/// force touch functionality, with the exception of the iPhone XR. In addition,
	/// a small handful of Android devices have this functionality as well.
	///
	/// Devices with faux screen pressure sensors like the Pixel 2 and 3 will not
	/// send any force press related callbacks.
	///
	/// Reported pressure will always be in the range 0.0 to 1.0, where 1.0 is
	/// maximum pressure and 0.0 is minimum pressure. If using a custom
	/// [interpolation] callback, the pressure reported will correspond to that
	/// custom curve.
	class ForcePressGestureRecognizer extends OneSequenceGestureRecognizer {
	/// Creates a force press gesture recognizer.
	///
	/// The [startPressure] defaults to 0.4, and [peakPressure] defaults to 0.85
	/// where a value of 0.0 is no pressure and a value of 1.0 is maximum pressure.
	///
	/// The [startPressure], [peakPressure] and [interpolation] arguments must not
	/// be null. The [peakPressure] argument must be greater than [startPressure].
	/// 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, 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
	/// detectors, only the force press gesture will be detected and all others
	/// will be rejected.
	///
	/// The position of the pointer is provided in the callback's `details`
	/// argument, which is a [ForcePressDetails] object.
	GestureForcePressStartCallback onStart;

	/// A pointer is in contact with the screen and is either moving on the plane
	/// of the screen, pressing the screen with varying forces or both
	/// simultaneously.
	///
	/// This callback will be invoked for every pointer event after the invocation
	/// of [onStart] and/or [onPeak] and before the invocation of [onEnd], no
	/// matter what the pressure is during this time period. The position and
	/// pressure of the pointer is provided in the callback's `details` argument,
	/// which is a [ForcePressDetails] object.
	GestureForcePressUpdateCallback onUpdate;

	/// A pointer is in contact with the screen and has just pressed with a force
	/// exceeding the [peakPressure]. This is an arbitrary second level action
	/// threshold and isn't necessarily the maximum possible device pressure
	/// (which is 1.0).
	///
	/// The position of the pointer is provided in the callback's `details`
	/// argument, which is a [ForcePressDetails] object.
	GestureForcePressPeakCallback onPeak;

	/// A pointer is no longer in contact with the screen.
	///
	/// The position of the pointer is provided in the callback's `details`
	/// argument, which is a [ForcePressDetails] object.
	GestureForcePressEndCallback onEnd;

	/// The pressure of the press required to initiate a force press.
	///
	/// A value of 0.0 is no pressure, and 1.0 is maximum pressure.
	final double startPressure;

	/// The pressure of the press required to peak a force press.
	///
	/// A value of 0.0 is no pressure, and 1.0 is maximum pressure. This value
	/// must be greater than [startPressure].
	final double peakPressure;

	/// The function used to convert the raw device pressure values into a value
	/// in the range 0.0 to 1.0.
	///
	/// The function takes in the device's minimum, maximum and raw touch pressure
	/// and returns a value in the range 0.0 to 1.0 denoting the interpolated
	/// touch pressure.
	///
	/// This function must always return values in the range 0.0 to 1.0 given a
	/// pressure that is between the minimum and maximum pressures. It may return
	/// `double.NaN` for values that it does not want to support.
	///
	/// By default, the function is a linear interpolation; however, changing the
	/// function could be useful to accommodate variations in the way different
	/// devices respond to pressure, or to change how animations from pressure
	/// feedback are rendered.
	///
	/// For example, an ease-in curve can be used to determine the interpolated
	/// value:
	///
	/// ```dart
	/// static double interpolateWithEasing(double min, double max, double t) {
	/// final double lerp = (t - min) / (max - min);
	/// return Curves.easeIn.transform(lerp);
	/// }
	/// ```
	final GestureForceInterpolation interpolation;

	OffsetPair _lastPosition;
	double _lastPressure;
	_ForceState _state = _ForceState.ready;

	@override
	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.
	if (event is! PointerUpEvent && event.pressureMax <= 1.0) {
	resolve(GestureDisposition.rejected);
	} else {
	startTrackingPointer(event.pointer, event.transform);
	if (_state == _ForceState.ready) {
	_state = _ForceState.possible;
	_lastPosition = OffsetPair.fromEventPosition(event);
	}
	}
	}

	@override
	void handleEvent(PointerEvent event) {
	assert(_state != _ForceState.ready);
	// A static pointer with changes in pressure creates PointerMoveEvent events.
	if (event is PointerMoveEvent \|\| event is PointerDownEvent) {
	if (event.pressure > event.pressureMax \|\| event.pressure < event.pressureMin) {
	debugPrint(
	'The reported device pressure ' + event.pressure.toString() +
	' is outside of the device pressure range where: ' +
	event.pressureMin.toString() + ' <= pressure <= ' + event.pressureMax.toString(),
	);
	}

	final double pressure = interpolation(event.pressureMin, event.pressureMax, event.pressure);
	assert(
	(pressure >= 0.0 && pressure <= 1.0) \|\| // Interpolated pressure must be between 1.0 and 0.0...
	pressure.isNaN // and interpolation may return NaN for values it doesn't want to support...
	);

	_lastPosition = OffsetPair.fromEventPosition(event);
	_lastPressure = pressure;

	if (_state == _ForceState.possible) {
	if (pressure > startPressure) {
	_state = _ForceState.started;
	resolve(GestureDisposition.accepted);
	} else if (event.delta.distanceSquared > kTouchSlop) {
	resolve(GestureDisposition.rejected);
	}
	}
	// In case this is the only gesture detector we still don't want to start
	// the gesture until the pressure is greater than the startPressure.
	if (pressure > startPressure && _state == _ForceState.accepted) {
	_state = _ForceState.started;
	if (onStart != null) {
	invokeCallback<void>('onStart', () => onStart(ForcePressDetails(
	pressure: pressure,
	globalPosition: _lastPosition.global,
	localPosition: _lastPosition.local,
	)));
	}
	}
	if (onPeak != null && pressure > peakPressure &&
	(_state == _ForceState.started)) {
	_state = _ForceState.peaked;
	if (onPeak != null) {
	invokeCallback<void>('onPeak', () => onPeak(ForcePressDetails(
	pressure: pressure,
	globalPosition: event.position,
	localPosition: event.localPosition,
	)));
	}
	}
	if (onUpdate != null && !pressure.isNaN &&
	(_state == _ForceState.started \|\| _state == _ForceState.peaked)) {
	if (onUpdate != null) {
	invokeCallback<void>('onUpdate', () => onUpdate(ForcePressDetails(
	pressure: pressure,
	globalPosition: event.position,
	localPosition: event.localPosition,
	)));
	}
	}
	}
	stopTrackingIfPointerNoLongerDown(event);
	}

	@override
	void acceptGesture(int pointer) {
	if (_state == _ForceState.possible)
	_state = _ForceState.accepted;

	if (onStart != null && _state == _ForceState.started) {
	invokeCallback<void>('onStart', () => onStart(ForcePressDetails(
	pressure: _lastPressure,
	globalPosition: _lastPosition.global,
	localPosition: _lastPosition.local,
	)));
	}
	}

	@override
	void didStopTrackingLastPointer(int pointer) {
	final bool wasAccepted = _state == _ForceState.started \|\| _state == _ForceState.peaked;
	if (_state == _ForceState.possible) {
	resolve(GestureDisposition.rejected);
	return;
	}
	if (wasAccepted && onEnd != null) {
	if (onEnd != null) {
	invokeCallback<void>('onEnd', () => onEnd(ForcePressDetails(
	pressure: 0.0,
	globalPosition: _lastPosition.global,
	localPosition: _lastPosition.local,
	)));
	}
	}
	_state = _ForceState.ready;
	}

	@override
	void rejectGesture(int pointer) {
	stopTrackingPointer(pointer);
	didStopTrackingLastPointer(pointer);
	}

	static double _inverseLerp(double min, double max, double t) {
	assert(min <= max);
	double value = (t - min) / (max - min);

	// If the device incorrectly reports a pressure outside of pressureMin
	// and pressureMax, we still want this recognizer to respond normally.
	if (!value.isNaN)
	value = value.clamp(0.0, 1.0) as double;
	return value;
	}

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