| -api-id | -api-type |
|---|---|
P:Microsoft.UI.Composition.Interactions.InteractionTracker.NaturalRestingPosition |
winrt property |
Natural resting position for the InteractionTracker.
The NaturalRestingPosition property is the calculated position that InteractionTracker will come to a stop at without accounting for boundaries or inertia modifiers. This property is often useful for actions like virtualization in a scrolling experience, where it is important to know the location of where InteractionTracker will stop. There are two main use cases for using the NaturalRestingPosition property: Retrieving its current value in the InertiaStateEntered event args or referencing this property in an ExpressionAnimation when creating things like inertia modifiers.
Natural resting position for the InteractionTracker.
The two use cases described in the code snippet above are the primary uses of the NaturalRestingPosition property. Although you may be tempted to reference this property off InteractionTracker like any other object.property relationship, you will not always get the most up-to-date value. It is recommended in this situation that you listen for the InertiaStateEntered event and grab the latest value from the arguments.
// Listen for the InertiaStateEntered event, so can grab NaturalRestingPosition value.
public void InertiaStateEntered(InteractionTracker sender, InteractionTrackerInertiaStateEnteredArgs args)
{
// Grab the NaturalRestingPosition out of the args when the event is fired. Now have access to calculated Natural Rest spot
Vector3 naturalRest = args.NaturalRestingPosition;
}
// Reference the NaturalRestingPosition property in an expression for things like SnapPoints
void CreateBasicSnapPoint(float highBound, float lowBound)
{
var snappoint = InteractionTrackerInertiaRestingValue.Create(_compositor);
// Reference the NaturalRestingPosition of InteractionTracker in an ExpressionAnimation for conditional portion of an InertiaModifier.
snappoint.Condition = _compositor.CreateExpressionAnimation("this.target.NaturalRestingPosition.Y >= lowBound && this.target.NaturalRestingPosition.Y < highBound ");
snappoint.Condition.SetScalarParameter("lowBound", lowBound);
snappoint.Condition.SetScalarParameter("highBound", highBound);
// Snap to the highbound if condition met
snappoint.RestingValue = _compositor.CreateExpressionAnimation("highBound");
snappoint.RestingValue.SetScalarParameter("highBound", highBound);
yInertiaModifier.Add(snappoint);
_tracker.ConfigurePositionYInertiaModifiers(yInertiaModifier);
}