Merge "Add velocity threshold so that fast pinches (flings) are detected."...

public class PinchToOverviewListener extends ScaleGestureDetector.SimpleOnScaleGestureListener {

    private static final float OVERVIEW_PROGRESS = 0f;

    private static final float WORKSPACE_PROGRESS = 1f;

    /**

     * The velocity threshold at which a pinch will be completed instead of canceled,

     * even if the first threshold has not been passed. Measured in progress / millisecond

     */

    private static final float FLING_VELOCITY = 0.003f;

    private ScaleGestureDetector mPinchDetector;

    private Launcher mLauncher;

    public void onScaleEnd(ScaleGestureDetector detector) {

        super.onScaleEnd(detector);

        float progressVelocity = mProgressDelta / mTimeDelta;

        float passedThreshold = mThresholdManager.getPassedThreshold();

        boolean isFling = mWorkspace.isInOverviewMode() && progressVelocity >= FLING_VELOCITY

                || !mWorkspace.isInOverviewMode() && progressVelocity <= -FLING_VELOCITY;

        boolean shouldCancelPinch = !isFling && passedThreshold < PinchThresholdManager.THRESHOLD_ONE;

        // If we are going towards overview, mPreviousProgress is how much further we need to

        // go, since it is going from 1 to 0. If we are going to workspace, we want

        // 1 - mPreviousProgress.

        float remainingProgress = mPreviousProgress;

        if (mWorkspace.isInOverviewMode() || passedThreshold < PinchThresholdManager.THRESHOLD_ONE) {

        if (mWorkspace.isInOverviewMode() || shouldCancelPinch) {

            remainingProgress = 1f - mPreviousProgress;

        }

        int duration = computeDuration(remainingProgress, mProgressDelta, mTimeDelta);

        if (passedThreshold < PinchThresholdManager.THRESHOLD_ONE) {

        int duration = computeDuration(remainingProgress, progressVelocity);

        if (shouldCancelPinch) {

            cancelPinch(mPreviousProgress, duration);

        } else if (passedThreshold < PinchThresholdManager.THRESHOLD_THREE) {

            float toProgress = mWorkspace.isInOverviewMode() ?

     * Compute the amount of time required to complete the transition based on the current pinch

     * speed. If this time is too long, instead return the normal duration, ignoring the speed.

     */

    private int computeDuration(float remainingProgress, float progressDelta, long timeDelta) {

        float progressSpeed = Math.abs(progressDelta) / timeDelta;

    private int computeDuration(float remainingProgress, float progressVelocity) {

        float progressSpeed = Math.abs(progressVelocity);

        int remainingMillis = (int) (remainingProgress / progressSpeed);

        return Math.min(remainingMillis, mAnimationManager.getNormalOverviewTransitionDuration());

    }