private double CalculateYOffset(FrameworkElement itemToAnimate)
{
FrameworkElement rootElement = this.containerToAnimate; // TODO - get the root
Point globalCoords = ElementTreeHelper.SafeTransformPoint(itemToAnimate, rootElement, new Point());
double heightAdjustment = itemToAnimate.ActualHeight / 2;
double yCoord = globalCoords.Y + heightAdjustment;
return((rootElement.ActualHeight / 2) - yCoord);
}
private bool IsItemVisible(FrameworkElement itemToAdd)
{
if (itemToAdd == null || itemToAdd.Visibility == Visibility.Collapsed)
{
return(false);
}
Size renderSize = itemToAdd.RenderSize;
if (renderSize.Width == 0 || renderSize.Height == 0)
{
return(false);
}
FrameworkElement rootVisual = Window.Current.Content as FrameworkElement;
Point globalPosition = ElementTreeHelper.SafeTransformPoint(itemToAdd, rootVisual, new Point());
double itemWidth = itemToAdd.Width;
double itemHeight = itemToAdd.Height;
if ((globalPosition.X + itemWidth) < 0 ||
(globalPosition.Y + itemHeight) < 0 ||
globalPosition.X > rootVisual.ActualWidth ||
globalPosition.Y > rootVisual.ActualHeight)
{
return(false);
}
ScrollViewer parentScrollViewer = ElementTreeHelper.FindVisualAncestor <ScrollViewer>(itemToAdd);
if (parentScrollViewer != null)
{
Point localPosition = ElementTreeHelper.SafeTransformPoint(itemToAdd, parentScrollViewer, new Point());
if ((localPosition.X + itemWidth) < 0 ||
(localPosition.Y + itemHeight) < 0 ||
localPosition.X > parentScrollViewer.ActualWidth ||
localPosition.Y > parentScrollViewer.ActualHeight)
{
return(false);
}
}
return(true);
}