/// <summary>
/// Stops all animations that affect the animation tree (such as animations that control the
/// speed ratios or animation weights).
/// </summary>
/// <param name="animationManager">The <see cref="AnimationManager"/>.</param>
internal void StopSecondaryAnimations(AnimationManager animationManager)
{
if (((IAnimatableProperty <float>)_speedProperty).IsAnimated)
{
animationManager.StopAnimation(_speedProperty);
animationManager.UpdateAndApplyAnimation(_speedProperty);
}
if (((IAnimatableProperty <float>)_weightProperty).IsAnimated)
{
animationManager.StopAnimation(_weightProperty);
animationManager.UpdateAndApplyAnimation(_weightProperty);
}
foreach (var child in Children)
{
child.StopSecondaryAnimations(animationManager);
}
}
/// <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);
}
}
}
/// <inheritdoc/>
public void Update(AnimationManager animationManager)
{
IAnimatableProperty<T> property = Property;
if (property == null)
{
// The animated object has been garbage collected.
return;
}
int numberOfAnimations = Items.Count;
if (numberOfAnimations == 0)
{
// All animations have stopped or were removed.
if (property is ImmediateAnimatableProperty<T>)
{
// Special: Certain properties need to be set immediately.
// All other properties are set in Apply();
ResetProperty(property);
}
return;
}
// Get the property's base value.
T baseValue;
if (property.HasBaseValue)
{
// The animatable property has a base value.
baseValue = property.BaseValue;
}
else
{
// The animatable property does not have a base value.
// Use identity. (Create a temporary object if necessary.)
_traits.Create(ref _value, out baseValue);
_traits.SetIdentity(ref baseValue);
}
// Get the start value of the composition chain.
if (_hasSnapshot)
{
// An animation snapshot has been taken previously.
// Start composition chain with animation snapshot.
_traits.Copy(ref _snapshot, ref _value);
}
else
{
// Start the composition chain with the base value.
_traits.Copy(ref baseValue, ref _value);
}
// Compose the animations in the composition chain.
for (int i = 0; i < numberOfAnimations; i++)
{
var animationInstance = Items[i];
// The source value is the output of the previous stage in the composition chain: _value.
// The target value is the base value of the animated property: baseValue.
// Store the output of the current stage in _value.
animationInstance.GetValue(ref _value, ref baseValue, ref _value);
}
if (!property.HasBaseValue)
{
// Recycle baseValue which was created previously.
_traits.Recycle(ref baseValue);
}
if (property is ImmediateAnimatableProperty<T>)
{
// Special: Certain properties need to be set immediately.
// All other properties are set in Apply();
SetProperty(property);
}
}