InteractionTracker.TryUpdatePositionWithAnimation Method

Definition

Namespace:

Windows.UI.Composition.Interactions

Tries to update the InteractionTracker's position by applying an animation.

The TryUpdatePositionWithAnimation method updates the position of InteractionTracker based on the CompositionAnimation input as a parameter. This method is used in situations in which the motion of InteractionTracker needs to be defined by a specific animation, instead of the traditional Inertia experience. TryUpdatePositionWithAnimation can be called from the Idle or Inertia state – doing so, InteractionTracker ’s position will be driven by the defined animation and enter the CustomAnimation state.

public:
 virtual int TryUpdatePositionWithAnimation(CompositionAnimation ^ animation) = TryUpdatePositionWithAnimation;

int TryUpdatePositionWithAnimation(CompositionAnimation const& animation);

public int TryUpdatePositionWithAnimation(CompositionAnimation animation);

function tryUpdatePositionWithAnimation(animation)

Public Function TryUpdatePositionWithAnimation (animation As CompositionAnimation) As Integer

Parameters

animation

CompositionAnimation

The animation to apply to the InteractionTracker.

Returns

Int32

int

Returns the request ID. On state transitions, the request which caused the change in state will be included in the args. These IDs will start at 1 and increase with each try call during the lifetime of the application.

Examples

void CustomAnimationForIT(Vector3 newPosition)
{
  // Create a cubic bezier easing function that will be used in the KeyFrames
  CompositionEasingFunction cubicBezier = _compositor.CreateCubicBezierEasingFunction(new Vector2(.17f, .67f), new Vector2(1f, 1f);

  // Create the Vector3 KFA
  Vector3KeyFrameAnimation kfa = _compositor.CreateVector3KeyFrameAnimation();
  kfa.Duration = TimeSpan.FromSeconds(3);

  // Create the KeyFrames
  kfa.InsertKeyFrame(1.0f, newPosition, cubicBezier);

  // Update InteractionTracker position using this animation
  _tracker.TryUpdatePositionWithAnimation(kfa);
}

Remarks

When creating the animation you want to update InteractionTracker ’s position with, you do not need to call StartAnimation. The system will take care of this behind the scenes once the animation is passed in via TryUpdatePositionWithAnimation.

When defining the animation that will animate InteractionTracker ’s position, be sure to either use a Vector3KeyFrameAnimation or an ExpressionAnimation that resolves to a Vector3.

The table below summarizes the expected behavior when this method is called in a particular state:

Current State	Outcome
Idle	Requested animation starts on requested property, state changes to CustomAnimation
Interacting	Request ignored
Inertia	Requested animation starts on requested property, state changes to CustomAnimation
CustomAnimation	Current animation stops and new requested animation starts on requested property, state re-enters CustomAnimation