private void HandlePan(UIPanGestureRecognizer recognizer)
{
var translation = recognizer.TranslationInView(this);
Trace($"Pan translation: {translation.X}/{translation.Y}");
StopDeceleration();
switch (recognizer.State)
{
case UIGestureRecognizerState.Began:
panGestureLastTranslation = recognizer.TranslationInView(this);
ViewPort.Offset(panGestureLastTranslation);
break;
case UIGestureRecognizerState.Changed:
var translationOffset = new CGPoint(panGestureLastTranslation.X - translation.X, panGestureLastTranslation.Y - translation.Y);
ViewPort.Offset(translationOffset);
Trace($"Pan translationOffset: {translationOffset.X}/{translationOffset.Y}");
panGestureLastTranslation = translation;
break;
case UIGestureRecognizerState.Ended:
Trace($"Pan gesture ended");
var velocity = recognizer.VelocityInView(this);
Trace($"Pan gesture velocity: {velocity.X}/{velocity.Y}");
InitDeceleration(velocity);
break;
default:
break;
}
SetNeedsDisplay();
}