Handle a fling/scroll in Android without consuming the MotionEvent
I've got a ViewFlipper at the side of the screen in my app containing a bunch of different views, and I would like the user to be able to dismiss this by swiping to the left. So I did the usual...
private class SwipeDetector extends SimpleOnGestureListener {
@Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
//Dismiss view
}
@Override
public boolean onDown(MotionEvent e) {
return true;
}
}
...and then set the onTouchListener of the ViewFlipper to call onTouchEvent in SwipeDetector. It all worked great, however I then noticed because it was consuming all the touch events going into the ViewFlipper, I couldn't click anything when the ViewFlipper itself. If I don't override onDown or I make it return false then the TouchListener ignores the rest of the event and I don't get the fling. I'm happy to hack together some kind of custom swipe detection if I could even handle all the ACTION_MOVE events following the user touching the ViewFlipper but can't even do that. Is there any way to keep listening to the MotionEvent without consuming the onDown?
What works for me is extending View.OnTouchListener instead of SimpleGestureListener , and override onTouch method. Please, take this snippet as a very simple (and improvable) approach to get horizontal swipe detection.-
public boolean onTouch(View v, MotionEvent event) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN: {
downX = event.getX();
return true;
}
case MotionEvent.ACTION_UP: {
upX = event.getX();
float deltaX = downX - upX;
if (Math.abs(deltaX) > MIN_DISTANCE) {
if (deltaX < 0) {
this.onLeftToRightSwipe();
return true;
}
if (deltaX > 0) {
this.onRightToLeftSwipe();
return true;
}
return true;
}
return true;
}
}
return false;
}
Did you notice the GestureDetector? It is available since API Version 1.
http://developer.android.com/reference/android/view/GestureDetector.OnGestureListener.html
Both fling and scroll gestures are handled.
链接地址: http://www.djcxy.com/p/91252.html