VelocityTracker

fun addPosition(timeMillis: Long, position: Offset): Unit

Adds a position at the given time to the tracker.

Call resetTracking to remove added Offsets.

fun calculateVelocity(): Velocity

Computes the estimated velocity of the pointer at the time of the last provided data point.

The velocity calculated will not be limited. Unlike calculateVelocity(maximumVelocity) the resulting velocity won't be limited.

This can be expensive. Only call this when you need the velocity.

fun calculateVelocity(maximumVelocity: Velocity): Velocity

Computes the estimated velocity of the pointer at the time of the last provided data point.

The method allows specifying the maximum absolute value for the calculated velocity. If the absolute value of the calculated velocity exceeds the specified maximum, the return value will be clamped down to the maximum. For example, if the absolute maximum velocity is specified as "20", a calculated velocity of "25" will be returned as "20", and a velocity of "-30" will be returned as "-20".

fun resetTracking(): Unit

Clears the tracked positions added by addPosition.

fun VelocityTracker.addPointerInputChange(event: PointerInputChange): Unit

Track the positions and timestamps inside this event change.

For optimal tracking, this should be called for the DOWN event and all MOVE events, including any touch-slop-captured MOVE event.

Since Compose uses relative positions inside PointerInputChange, this should be taken into consideration when using this method. Right now, we use the first down to initialize an accumulator and use subsequent deltas to simulate an actual movement from relative positions in PointerInputChange. This is required because VelocityTracker requires data that can be fit into a curve, which might not happen with relative positions inside a moving target for instance.