private UIPanGestureRecognizer CreatePanGesture()
{
UIPanGestureRecognizer result = null;
nfloat dy = 0;
nfloat navX = 70;
result = new UIPanGestureRecognizer(() => {
if ((result.State == UIGestureRecognizerState.Began || result.State == UIGestureRecognizerState.Changed) && (result.NumberOfTouches == 1))
{
_isDragging = true;
var p0 = result.LocationInView(this);
var currentY = (_position == ChartPosition.Top) ? topY : downY;
if (dy.CompareTo(0) == 0)
{
dy = p0.Y - currentY;
}
var p1 = new CGPoint(_containerView.Center.X, p0.Y - dy);
if (p1.Y > topY || p1.Y < downY)
{
return;
}
_containerView.Center = p1;
}
else if (result.State == UIGestureRecognizerState.Ended)
{
nfloat newY;
ChartPosition newPosition;
if (_position == ChartPosition.Top && _containerView.Center.Y <= topY - navX)
{
newPosition = ChartPosition.Down;
newY = downY;
}
else if (_position == ChartPosition.Down && _containerView.Center.Y >= downY + navX)
{
newPosition = ChartPosition.Top;
newY = topY;
}
else
{
newPosition = _position;
newY = (_position == ChartPosition.Top) ? topY : downY;
}
UIView.Animate(0.3, 0, UIViewAnimationOptions.CurveEaseOut,
() => {
_containerView.Center = new CGPoint(_containerView.Center.X, newY);
}, () => {
_isDragging = false;
_position = newPosition;
});
dy = 0;
}
});
return(result);
}