private static CompositeTransform GetAttachedCompositeTransform(UIElement element)
{
// We need to use an index to keep track of our CompositeTransform as animation engine
// recreates new transform objects when animating properties
// Already attached?
var compositeTransformIndex = AnimationTools.GetAnimationCompositeTransformIndex(element);
if (compositeTransformIndex > -2)
{
if (compositeTransformIndex == -1 && element.RenderTransform is CompositeTransform)
{
return((CompositeTransform)element.RenderTransform);
}
var group = element.RenderTransform as TransformGroup;
if (group?.Children.Count > compositeTransformIndex && group.Children[compositeTransformIndex] is CompositeTransform)
{
return((CompositeTransform)group.Children[compositeTransformIndex]);
}
}
// Let's create a new CompositeTransform
var result = new CompositeTransform();
var currentTransform = element.RenderTransform;
if (currentTransform != null)
{
// We found a RenderTransform
// Is it a TransformGroup?
var currentTransformGroup = currentTransform as TransformGroup;
if (currentTransformGroup != null)
{
currentTransformGroup.Children.Add(result);
AnimationTools.SetAnimationCompositeTransformIndex(element, currentTransformGroup.Children.Count - 1);
}
else
{
// Let's create our own TransformGroup
var group = new TransformGroup();
group.Children.Add(currentTransform);
group.Children.Add(result);
element.RenderTransform = group;
AnimationTools.SetAnimationCompositeTransformIndex(element, 1);
}
}
else
{
element.RenderTransform = result;
AnimationTools.SetAnimationCompositeTransformIndex(element, -1);
}
return(result);
}
