/// <inheritdoc/>
internal override void RemoveFromCompositionChains(AnimationManager animationManager)
{
var property = Property;
var compositionChain = animationManager.GetCompositionChain(property, null, false);
if (compositionChain != null)
{
compositionChain.Remove(this);
}
}
/// <inheritdoc/>
internal override bool IsActive(AnimationManager animationManager)
{
var property = Property;
var compositionChain = animationManager.GetCompositionChain(property, null, false);
if (compositionChain != null && compositionChain.Contains(this))
{
return(true);
}
return(false);
}
/// <inheritdoc/>
internal override void AddToCompositionChains(AnimationManager animationManager, HandoffBehavior handoffBehavior, AnimationInstance previousInstance)
{
var property = Property;
if (property == null)
{
return;
}
// Get (or create) the animation composition chain.
var compositionChain = animationManager.GetCompositionChain(property, Animation.Traits, true);
if (handoffBehavior == HandoffBehavior.SnapshotAndReplace)
{
// Make a snapshot of the current animation value.
compositionChain.TakeSnapshot();
}
if (handoffBehavior == HandoffBehavior.Replace || handoffBehavior == HandoffBehavior.SnapshotAndReplace)
{
// Remove all previous animations.
if (compositionChain.Count > 0)
{
var rootInstance = this.GetRoot();
for (int i = compositionChain.Count - 1; i >= 0; i--)
{
var animationInstance = compositionChain[i];
// Do not remove animation instances of the same animation tree!
if (animationInstance.GetRoot() != rootInstance)
{
compositionChain.RemoveAt(i);
}
}
}
}
AnimationInstance <T> referenceInstance = null;
if (previousInstance != null)
{
// previousInstance is either a single animation instance or an animation tree that
// should be replaced. Find the instance that is assigned to the current property.
referenceInstance = previousInstance.GetAssignedInstance(Property) as AnimationInstance <T>;
}
if (referenceInstance == null)
{
// Add at the end of the animation composition chain.
compositionChain.Add(this);
}
else
{
// Insert in animation composition chain at a certain index.
int index = compositionChain.IndexOf(referenceInstance);
if (index == -1)
{
// The referenceInstance has not been applied to the current property.
compositionChain.Add(this);
}
else
{
// Insert after referenceInstance.
index++;
// Other animation instances of the same animation tree might have already been
// inserted after referenceInstance. To maintain the correct order we need to add
// this instance after the other instances of the same tree.
var rootInstance = this.GetRoot();
var numberOfInstances = compositionChain.Count;
while (index < numberOfInstances && compositionChain[index].GetRoot() == rootInstance)
{
index++;
}
compositionChain.Insert(index, this);
}
}
}