private void onSecondaryPointerUp(MotionEvent ev) {
        final int pointerIndex = MotionEventCompat.getActionIndex(ev);
        final int pointerId = MotionEventCompat.getPointerId(ev, pointerIndex);
        if (pointerId == mActivePointerId) {
            // This was our active pointer going up. Choose a new
            // active pointer and adjust accordingly.
            final int newPointerIndex = pointerIndex == 0 ? 1 : 0;
            mLastMotionX = MotionEventCompat.getX(ev, newPointerIndex);
            mActivePointerId = MotionEventCompat.getPointerId(ev, newPointerIndex);
            if (mVelocityTracker != null) {
                mVelocityTracker.clear();
            }
        }
    }
Returns true if a fake drag is in progress.

@return true if currently in a fake drag, false otherwise.

@see #beginFakeDrag()
@see #fakeDragBy(float)
@see #endFakeDrag()
library/src/main/java/com/daimajia/slider/library/Tricks/ViewPagerEx.java