public InertiaProcessor(Manipulation owner, Point position, ManipulationDelta cumulative, ManipulationVelocities velocities)
{
_owner = owner;
_position0 = position;
_cumulative0 = cumulative;
_velocities0 = velocities;
_isTranslateInertiaXEnabled = _owner._isTranslateXEnabled &&
_owner._settings.HasFlag(Input.GestureSettings.ManipulationTranslateInertia) &&
Abs(velocities.Linear.X) > _owner._inertiaThresholds.TranslateX;
_isTranslateInertiaYEnabled = _owner._isTranslateYEnabled &&
_owner._settings.HasFlag(Input.GestureSettings.ManipulationTranslateInertia) &&
Abs(velocities.Linear.Y) > _owner._inertiaThresholds.TranslateY;
_isRotateInertiaEnabled = _owner._isRotateEnabled &&
_owner._settings.HasFlag(Input.GestureSettings.ManipulationRotateInertia) &&
Abs(velocities.Angular) > _owner._inertiaThresholds.Rotate;
_isScaleInertiaEnabled = _owner._isScaleEnabled &&
_owner._settings.HasFlag(Input.GestureSettings.ManipulationScaleInertia) &&
Abs(velocities.Expansion) > _owner._inertiaThresholds.Expansion;
global::System.Diagnostics.Debug.Assert(_isTranslateInertiaXEnabled || _isTranslateInertiaYEnabled || _isRotateInertiaEnabled || _isScaleInertiaEnabled);
// For better experience, as soon inertia kicked-in on an axis, we bypass threshold on the second axis.
_isTranslateInertiaXEnabled |= _isTranslateInertiaYEnabled && _owner._isTranslateXEnabled;
_isTranslateInertiaYEnabled |= _isTranslateInertiaXEnabled && _owner._isTranslateYEnabled;
_timer = DispatcherQueue.GetForCurrentThread().CreateTimer();
_timer.Interval = TimeSpan.FromMilliseconds(1000d / _framesPerSecond);
_timer.IsRepeating = true;
_timer.Tick += (snd, e) => Process(snd.LastTickElapsed.TotalMilliseconds);
}
internal ManipulationInertiaStartingEventArgs(PointerDeviceType pointerDeviceType, Point position, ManipulationDelta delta, ManipulationDelta cumulative)
{
PointerDeviceType = pointerDeviceType;
Position = position;
Delta = delta;
Cumulative = cumulative;
}
private void NotifyUpdate(bool pointerAdded = false)
{
// Note: Make sure to update the _sumOfPublishedDelta before raising the event, so if an exception is raised
// or if the manipulation is Completed, the Complete event args can use the updated _sumOfPublishedDelta.
var cumulative = GetCumulative();
switch (_state)
{
case ManipulationState.Starting when pointerAdded:
_state = ManipulationState.Started;
_sumOfPublishedDelta = cumulative;
_recognizer.ManipulationStarted?.Invoke(
_recognizer,
new ManipulationStartedEventArgs(_deviceType, _currents.Center, cumulative));
// No needs to publish an update when we start the manipulation due to an additional pointer as cumulative will be empty.
break;
case ManipulationState.Starting when cumulative.IsSignificant(_startThresholds):
_state = ManipulationState.Started;
_sumOfPublishedDelta = cumulative;
// Note: We first start with an empty delta, then invoke Update.
// This is required to patch a common issue in applications that are using only the
// ManipulationUpdated.Delta property to track the pointer (like the WCT GridSplitter).
// UWP seems to do that only for Touch and Pen (i.e. the Delta is not empty on start with a mouse),
// but there is no side effect to use the same behavior for all pointer types.
_recognizer.ManipulationStarted?.Invoke(
_recognizer,
new ManipulationStartedEventArgs(_deviceType, _origins.Center, ManipulationDelta.Empty));
_recognizer.ManipulationUpdated?.Invoke(
_recognizer,
new ManipulationUpdatedEventArgs(_deviceType, _currents.Center, cumulative, cumulative, isInertial: false));
break;
case ManipulationState.Started:
// Even if Scale and Angle are expected to be default when we add a pointer (i.e. forceUpdate == true),
// the 'delta' and 'cumulative' might still contains some TranslateX|Y compared to the previous Pointer1 location.
var delta = GetDelta(cumulative);
if (pointerAdded || delta.IsSignificant(_deltaThresholds))
{
_sumOfPublishedDelta = _sumOfPublishedDelta.Add(delta);
_recognizer.ManipulationUpdated?.Invoke(
_recognizer,
new ManipulationUpdatedEventArgs(_deviceType, _currents.Center, delta, cumulative, isInertial: false));
}
break;
}
}
internal static ManipulationDelta Add(ManipulationDelta left, ManipulationDelta right)
=> new ManipulationDelta
{
Translation = new Point(
left.Translation.X + right.Translation.X,
left.Translation.Y + right.Translation.Y),
Rotation = left.Rotation + right.Rotation,
Scale = left.Scale * right.Scale,
Expansion = left.Expansion + right.Expansion
};
internal ManipulationCompletedEventArgs(
PointerDeviceType pointerDeviceType,
Point position,
ManipulationDelta cumulative,
bool isInertial)
{
PointerDeviceType = pointerDeviceType;
Position = position;
Cumulative = cumulative;
IsInertial = isInertial;
}
internal ManipulationStartedEventArgs(
PointerIdentifier[] pointers,
Point position,
ManipulationDelta cumulative,
uint contactCount)
{
global::System.Diagnostics.Debug.Assert(contactCount == pointers.Length, "We should have the same number of pointers for the manip start.");
global::System.Diagnostics.Debug.Assert(pointers.Length > 0 && pointers.All(p => p.Type == pointers[0].Type));
Pointers = pointers;
PointerDeviceType = pointers[0].Type;
Position = position;
Cumulative = cumulative;
ContactCount = contactCount;
}
private ManipulationDelta GetDelta(ManipulationDelta cumulative)
{
var deltaSum = _sumOfPublishedDelta;
var translateX = _isTranslateXEnabled ? cumulative.Translation.X - deltaSum.Translation.X : 0;
var translateY = _isTranslateYEnabled ? cumulative.Translation.Y - deltaSum.Translation.Y : 0;
var rotate = _isRotateEnabled ? cumulative.Rotation - deltaSum.Rotation : 0;
var scale = _isScaleEnabled ? cumulative.Scale / deltaSum.Scale : 1;
var expansion = _isScaleEnabled ? cumulative.Expansion - deltaSum.Expansion : 0;
return(new ManipulationDelta
{
Translation = new Point(translateX, translateY),
Rotation = (float)MathEx.NormalizeDegree(rotate),
Scale = scale,
Expansion = expansion
});
}
private ManipulationDelta GetInertiaCumulative(double t, ManipulationDelta previousCumulative)
{
var linearX = GetValue(_isTranslateInertiaXEnabled, _velocities0.Linear.X, DesiredDisplacementDeceleration, t, (float)previousCumulative.Translation.X);
var linearY = GetValue(_isTranslateInertiaYEnabled, _velocities0.Linear.Y, DesiredDisplacementDeceleration, t, (float)previousCumulative.Translation.Y);
var angular = GetValue(_isRotateInertiaEnabled, _velocities0.Angular, DesiredRotationDeceleration, t, previousCumulative.Rotation);
var expansion = GetValue(_isScaleInertiaEnabled, _velocities0.Expansion, DesiredExpansionDeceleration, t, previousCumulative.Expansion);
var scale = _isScaleInertiaEnabled ? (_owner._origins.Distance + expansion) / _owner._origins.Distance : 1;
var delta = new ManipulationDelta
{
Translation = new Point(linearX, linearY),
Rotation = angular,
Expansion = expansion,
Scale = scale
};
return(delta);
}
internal ManipulationCompletedEventArgs(
PointerIdentifier[] pointers,
Point position,
ManipulationDelta cumulative,
ManipulationVelocities velocities,
bool isInertial,
uint contactCount,
uint currentContactCount)
{
global::System.Diagnostics.Debug.Assert(pointers.Length > 0 && pointers.All(p => p.Type == pointers[0].Type));
Pointers = pointers;
Position = position;
Cumulative = cumulative;
Velocities = velocities;
IsInertial = isInertial;
ContactCount = contactCount;
CurrentContactCount = currentContactCount;
}
internal ManipulationInertiaStartingEventArgs(
PointerIdentifier[] pointers,
Point position,
ManipulationDelta delta,
ManipulationDelta cumulative,
ManipulationVelocities velocities,
uint contactCount,
GestureRecognizer.Manipulation.InertiaProcessor processor)
{
global::System.Diagnostics.Debug.Assert(pointers.Length > 0 && pointers.All(p => p.Type == pointers[0].Type));
Pointers = pointers;
PointerDeviceType = pointers[0].Type;
Position = position;
Delta = delta;
Cumulative = cumulative;
Velocities = velocities;
ContactCount = contactCount;
Processor = processor;
}
private void Process(double t)
{
// First we update the internal state (i.e. the current cumulative manip delta for the current time)
var previous = _inertiaCumulative;
var current = GetInertiaCumulative(t, previous);
_inertiaCumulative = current;
// Then we request to the owner to raise its events (will cause the GetCumulative())
// We notify in any cases in order to make sure to raise at least one ManipDelta (even if Delta.IsEmpty ^^) before stop the processor
_owner.NotifyUpdate();
if (previous.Translation.X == current.Translation.X &&
previous.Translation.Y == current.Translation.Y &&
previous.Rotation == current.Rotation &&
previous.Expansion == current.Expansion) // Note: we DO NOT compare the scaling, expansion is enough here!
{
_timer.Stop();
_owner.NotifyUpdate();
}
}
public FlickingEventArgs(FlickDirection direction, ManipulationDelta delta)
{
Direction = direction;
Delta = delta;
CanContinue = true;
}
private void NotifyUpdate(bool pointerAdded = false)
{
// Note: Make sure to update the _sumOfPublishedDelta before raising the event, so if an exception is raised
// or if the manipulation is Completed, the Complete event args can use the updated _sumOfPublishedDelta.
var cumulative = GetCumulative();
switch (_state)
{
case ManipulationState.Starting when IsBeginningOfDragManipulation():
// On UWP if the element was configured to allow both Drag and Manipulations,
// both events are going to be raised (... until the drag "content" is being render an captures all pointers).
// This results as a manipulation started which is never completed.
// If user uses double touch the manipulation will however start and complete when user adds / remove the 2nd finger.
// On Uno, as allowing both Manipulations and drop on the same element is really a stretch case (and is bugish on UWP),
// we accept as a known limitation that once dragging started no manipulation event would be fired.
_state = ManipulationState.Started;
IsDragManipulation = true;
_recognizer.Dragging?.Invoke(
_recognizer,
new DraggingEventArgs(_currents.Pointer1, DraggingState.Started));
break;
case ManipulationState.Starting when pointerAdded:
_state = ManipulationState.Started;
_sumOfPublishedDelta = cumulative;
_recognizer.ManipulationStarted?.Invoke(
_recognizer,
new ManipulationStartedEventArgs(_deviceType, _currents.Center, cumulative));
// No needs to publish an update when we start the manipulation due to an additional pointer as cumulative will be empty.
break;
case ManipulationState.Starting when cumulative.IsSignificant(_startThresholds):
_state = ManipulationState.Started;
_sumOfPublishedDelta = cumulative;
// Note: We first start with an empty delta, then invoke Update.
// This is required to patch a common issue in applications that are using only the
// ManipulationUpdated.Delta property to track the pointer (like the WCT GridSplitter).
// UWP seems to do that only for Touch and Pen (i.e. the Delta is not empty on start with a mouse),
// but there is no side effect to use the same behavior for all pointer types.
_recognizer.ManipulationStarted?.Invoke(
_recognizer,
new ManipulationStartedEventArgs(_deviceType, _origins.Center, ManipulationDelta.Empty));
_recognizer.ManipulationUpdated?.Invoke(
_recognizer,
new ManipulationUpdatedEventArgs(_deviceType, _currents.Center, cumulative, cumulative, isInertial: false));
break;
case ManipulationState.Started when IsDragManipulation:
_recognizer.Dragging?.Invoke(
_recognizer,
new DraggingEventArgs(_currents.Pointer1, DraggingState.Continuing));
break;
case ManipulationState.Started:
// Even if Scale and Angle are expected to be default when we add a pointer (i.e. forceUpdate == true),
// the 'delta' and 'cumulative' might still contains some TranslateX|Y compared to the previous Pointer1 location.
var delta = GetDelta(cumulative);
if (pointerAdded || delta.IsSignificant(_deltaThresholds))
{
_sumOfPublishedDelta = _sumOfPublishedDelta.Add(delta);
_recognizer.ManipulationUpdated?.Invoke(
_recognizer,
new ManipulationUpdatedEventArgs(_deviceType, _currents.Center, delta, cumulative, isInertial: false));
}
break;
}
}
private bool IsSignificant(ManipulationDelta delta) => Math.Abs(delta.Translation.X) >= MinManipulationDeltaTranslateX || Math.Abs(delta.Translation.Y) >= MinManipulationDeltaTranslateY || delta.Rotation >= MinManipulationDeltaRotate || // We used the ToDegreeNormalized, no need to check for negative angles Math.Abs(delta.Expansion) >= MinManipulationDeltaExpansion;
internal ManipulationStartedEventArgs(PointerDeviceType pointerDeviceType, Point position, ManipulationDelta cumulative)
{
PointerDeviceType = pointerDeviceType;
Position = position;
Cumulative = cumulative;
}
private DragLock GetDragLockForMove(ManipulationDelta cumulative)
{
if (!this.dragging)
{
this.ReleaseMouseCaptureAtGestureOrigin();
}
this.dragging = true;
if (this.dragLock == DragLock.Unset)
{
double num = GestureService.AngleFromVector(cumulative.Translation.X, cumulative.Translation.Y) % 180.0;
this.dragLock = num <= 45.0 || num >= 135.0 ? DragLock.Horizontal : DragLock.Vertical;
}
return this.dragLock;
}
protected virtual GestureEnd EndMove(bool isInertial, ManipulationDelta cumulative, ManipulationVelocities velocities, Point position)
{
this.dragLock = DragLock.Unset;
this.dragging = false;
double angle = 0.0;
if (isInertial)
{
angle = GestureService.AngleFromVector(velocities.Linear.X, velocities.Linear.Y);
if (angle <= 45.0 || angle >= 315.0)
{
angle = 0.0;
}
else if (angle >= 135.0 && angle <= 225.0)
{
angle = 180.0;
}
this.ReleaseMouseCaptureAtGestureOrigin();
}
return new GestureEnd(angle, isInertial, cumulative.Translation, position);
}
internal ManipulationDelta Add(ManipulationDelta right) => Add(this, right);