public override void ViewDidAppear(bool animated)
{
base.ViewDidAppear(animated);
UIView.Animate(0.3, 0, UIViewAnimationOptions.CurveEaseOut, () =>
{
this.View.BackgroundColor = OverlayColor;
ContainerView.Transform = CGAffineTransform.MakeIdentity();
_actualContainerSize = SheetSize.Fixed((float)ContainerView.Frame.Height);
}, null);
}
private float HeightFor(SheetSize type)
{
if (type == SheetSize.HalfScreen)
{
return((float)(UIScreen.MainScreen.Bounds.Height / 2 + 24));
}
else if (type == SheetSize.FullScreen)
{
var insets = safeAreaInsets();
return((float)(UIScreen.MainScreen.Bounds.Height - insets.Top - 20));
}
return(type.Value);
}
public void Resize(SheetSize toSize, bool animated = true)
{
if (animated)
{
UIView.Animate(0.2, 0, UIViewAnimationOptions.CurveEaseOut, () =>
{
_containerHeightConstraint.Constant = HeightFor(toSize);
this.View.LayoutIfNeeded();
}, null);
}
else
{
_containerHeightConstraint.Constant = HeightFor(toSize);
}
_containerSize = toSize;
_actualContainerSize = toSize;
}
void Panned(UIPanGestureRecognizer gesture)
{
var point = gesture.TranslationInView(gesture.View?.Superview);
if (gesture.State == UIGestureRecognizerState.Began)
{
_firstPanPoint = point;
_actualContainerSize = SheetSize.Fixed((float)ContainerView.Frame.Height);
}
var minHeight = Math.Min(HeightFor(_actualContainerSize), HeightFor(_orderedSheetSize.First()));
var maxHeight = Math.Max(HeightFor(_actualContainerSize), HeightFor(_orderedSheetSize.Last()));
var newHeight = Math.Max(0, HeightFor(_actualContainerSize) + _firstPanPoint.Y - point.Y);
float offset = 0;
if (newHeight < minHeight)
{
offset = minHeight - (float)newHeight;
newHeight = minHeight;
}
if (newHeight > maxHeight)
{
newHeight = maxHeight;
}
if (gesture.State == UIGestureRecognizerState.Cancelled || gesture.State == UIGestureRecognizerState.Failed)
{
UIView.Animate(0.3, 0, UIViewAnimationOptions.CurveEaseOut, () =>
{
ContainerView.Transform = CGAffineTransform.MakeIdentity();
_containerHeightConstraint.Constant = HeightFor(_containerSize);
}, null);
}
else if (gesture.State == UIGestureRecognizerState.Ended)
{
var velocity = (0.2 * gesture.VelocityInView(this.View).Y);
var finalHeight = newHeight - offset - velocity;
if (velocity > 500)
{
finalHeight = -1;
}
var animationDuration = (Math.Abs(velocity * 0.0002) + 0.2);
if (finalHeight <= (minHeight / 2))
{
UIView.Animate(animationDuration, 0, UIViewAnimationOptions.CurveEaseOut, () =>
{
this.View.BackgroundColor = UIColor.Clear;
ContainerView.Transform = CGAffineTransform.MakeTranslation(0, ContainerView.Frame.Height);
}, () => { this.DismissViewController(false, null); });
return;
}
var newSize = _containerSize;
if (point.Y < 0)
{
newSize = _orderedSheetSize.Last() ?? _containerSize;
foreach (var size in _orderedSheetSize.Reverse())
{
if (finalHeight < HeightFor(size))
{
newSize = size;
}
else
{
break;
}
}
}
else
{
newSize = _orderedSheetSize.First() ?? _containerSize;
foreach (var size in _orderedSheetSize)
{
if (finalHeight > HeightFor(size))
{
newSize = size;
}
else
{
break;
}
}
}
_containerSize = newSize;
UIView.Animate(animationDuration, 0, UIViewAnimationOptions.CurveEaseOut, () =>
{
ContainerView.Transform = CGAffineTransform.MakeIdentity();
_containerHeightConstraint.Constant = HeightFor(newSize);
this.View.LayoutIfNeeded();
}, () => { _actualContainerSize = SheetSize.Fixed((float)ContainerView.Frame.Height); });
}
else
{
_containerHeightConstraint.Constant = (float)newHeight;
if (offset > 0)
{
ContainerView.Transform = CGAffineTransform.MakeTranslation(0, offset);
}
else
{
ContainerView.Transform = CGAffineTransform.MakeIdentity();
}
}
}
