@Override
public boolean onTouchEvent(MotionEvent ev) {
super.onTouchEvent(ev);
if (velocityTracker == null) {
velocityTracker = VelocityTracker.obtain();
}
velocityTracker.addMovement(ev);
switch (ev.getAction()) {
case MotionEvent.ACTION_DOWN:
Log.d("ZoomRoll", "MotionEvent.ACTION_DOWN-----------1");
if (!scroller.isFinished()) {
scroller.abortAnimation();
zoomModel.commit();
}
lastX = ev.getX();
break;
case MotionEvent.ACTION_MOVE:
Log.d("ZoomRoll", "MotionEvent.ACTION_MOVE-----------2");
setCurrentValue(getCurrentValue() - (ev.getX() - lastX));
lastX = ev.getX();
break;
case MotionEvent.ACTION_UP:
Log.d("ZoomRoll", "MotionEvent.ACTION_UP-----------3");
velocityTracker.computeCurrentVelocity(1000);
scroller.fling(
(int) getCurrentValue(),
0,
(int) -velocityTracker.getXVelocity(),
0,
0,
MAX_VALUE,
0,
0);
velocityTracker.recycle();
velocityTracker = null;
if (!scroller.computeScrollOffset()) {
zoomModel.commit();
}
break;
}
invalidate();
return true;
}
@Override
public void computeScroll() {
if (scroller.computeScrollOffset()) {
setCurrentValue(scroller.getCurrX());
invalidate();
} else {
zoomModel.commit();
}
}
public void setCurrentValue(float currentValue) {
if (currentValue < 0.0) currentValue = 0.0f;
if (currentValue > MAX_VALUE) currentValue = MAX_VALUE;
final float zoom = 1.0f + currentValue / MULTIPLIER;
zoomModel.setZoom(zoom);
}
public float getCurrentValue() {
return (zoomModel.getZoom() - 1.0f) * MULTIPLIER;
}