private void DetectPinchAndPanGestures(TouchActionType touchActionType)
{
TouchManipulationInfo[] infos = new TouchManipulationInfo[_touchDictionary.Count];
_touchDictionary.Values.CopyTo(infos, 0);
if (infos.Length == 1)
{
SKPoint previousPoint = infos[0].PreviousPoint;
SKPoint newPoint = infos[0].NewPoint;
OnPan?.Invoke(this, new PanEventArgs(previousPoint, newPoint, touchActionType));
}
else if (infos.Length >= 2)
{
int pivotIndex = infos[0].NewPoint == infos[0].PreviousPoint ? 0 : 1;
SKPoint pivotPoint = infos[pivotIndex].NewPoint;
SKPoint newPoint = infos[1 - pivotIndex].NewPoint;
SKPoint previousPoint = infos[1 - pivotIndex].PreviousPoint;
OnPinch?.Invoke(this, new PinchEventArgs(previousPoint, newPoint, pivotPoint, touchActionType));
if (TwoFingersPanEnabled)
{
SKPoint delta = newPoint - previousPoint;
SKPoint halfOfDelta = new SKPoint(0.5f * delta.X, 0.5f * delta.Y);
OnPan?.Invoke(this, new PanEventArgs(new SKPoint(), halfOfDelta, touchActionType));
}
}
}
public void ProcessTouchEvent(long id, TouchActionType type, SKPoint location)
{
switch (type)
{
case TouchActionType.Pressed:
_touchDictionary.Add(id, new TouchManipulationInfo
{
PreviousPoint = location,
NewPoint = location,
MoveCounter = 0
});
break;
case TouchActionType.Moved:
if (!_touchDictionary.ContainsKey(id))
{
return;
}
TouchManipulationInfo info = _touchDictionary[id];
info.NewPoint = location;
info.MoveCounter = info.MoveCounter + 1;
DetectPinchAndPanGestures(type);
info.PreviousPoint = info.NewPoint;
break;
case TouchActionType.Released:
if (!_touchDictionary.ContainsKey(id))
{
return;
}
_touchDictionary[id].NewPoint = location;
DetectTapGestures();
DetectPinchAndPanGestures(type);
_touchDictionary.Remove(id);
break;
case TouchActionType.Cancelled:
if (!_touchDictionary.ContainsKey(id))
{
return;
}
_touchDictionary.Remove(id);
break;
}
}
private void DetectPinchAndPanGestures(TouchActionType touchActionType)
{
TouchManipulationInfo[] infos = new TouchManipulationInfo[_touchDictionary.Count];
_touchDictionary.Values.CopyTo(infos, 0);
if (infos.Length == 1)
{
SKPoint previousPoint = infos[0].PreviousPoint;
SKPoint newPoint = infos[0].NewPoint;
OnPan?.Invoke(this, new PanEventArgs(previousPoint, newPoint, touchActionType));
}
else if (infos.Length >= 2)
{
int pivotIndex = infos[0].NewPoint == infos[0].PreviousPoint ? 0 : 1;
SKPoint pivotPoint = infos[pivotIndex].NewPoint;
SKPoint newPoint = infos[1 - pivotIndex].NewPoint;
SKPoint previousPoint = infos[1 - pivotIndex].PreviousPoint;
OnPinch?.Invoke(this, new PinchEventArgs(previousPoint, newPoint, pivotPoint, touchActionType));
}
}
private void DetectTapGestures()
{
TouchManipulationInfo[] infos = new TouchManipulationInfo[_touchDictionary.Count];
_touchDictionary.Values.CopyTo(infos, 0);
if (infos.Length != 1)
{
return;
}
SKPoint point = infos[0].PreviousPoint;
if (infos[0].MoveCounter > MaxTapMoveCounter)
{
return;
}
var tapEventArgs = new TapEventArgs(point);
var now = DateTime.Now;
var lastTapTime = LastTapTime;
LastTapTime = now;
OnTap?.Invoke(this, tapEventArgs);
if (now - lastTapTime < DoubleTapDelay)
{
OnDoubleTap?.Invoke(this, tapEventArgs);
LastDoubleTapTime = now;
LastTapTime = DateTime.MinValue; //Reset double tap timer
}
else
{
_timer = new Timer(_ =>
{
if (DateTime.Now - LastDoubleTapTime < DoubleTapDelay)
{
return;
}
OnSingleTap?.Invoke(this, tapEventArgs);
}, null, DoubleTapDelay.Milliseconds, Timeout.Infinite);
}
}
