com.google.gwt.touch.client

Interface Momentum

All Known Implementing Classes:

DefaultMomentum

public interface Momentum

Describes the momentum of a gesture after the gesture has been completed. You can use it to control the speed of scrolling for scrollable widgets affected by TouchScroller.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	Momentum.State A snapshot of the current state.

Method Summary

Modifier and Type	Method and Description
Momentum.State	createState(Point initialPosition, Point initialVelocity) Create a Momentum.State instance.
boolean	updateState(Momentum.State state) Update the state based on the specified Momentum.State.

Method Detail

createState

Momentum.State createState(Point initialPosition,
                           Point initialVelocity)

Create a Momentum.State instance. The Momentum.State instance will be passed to updateState(State) until the momentum is depleted.

Parameters:

initialPosition - the initial position

initialVelocity - the initial velocity in pixels per millisecond

updateState

boolean updateState(Momentum.State state)

Update the state based on the specified Momentum.State. When no more momentum remains, this method should return false to stop future calls.

The Momentum.State instance is created by a call to createState(Point, Point), and the same instance if used for the duration of the momentum. This method should modify the existing state by calling Momentum.State.setPosition(Point) and/or Momentum.State.setVelocity(Point).

Parameters:

state - the current state

Returns:

true to continue momentum, false if no momentum remains