Custom onInterceptTouchEvent in ListView

Question

How can I implement a custom onInterceptTouchEvent() in a ListView that give the scrolling priority to the child's of the ListView and as soon as they did their scrolling , give it back to the ListView ? I want to give priority to the inner views.

Answer 1

Try overriding onInterceptTouchEvent() of your children like this:

@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
    if(!isAtTop && !isAtBottom){
        getParent().requestDisallowInterceptTouchEvent(true);   
    }             
    return super.onInterceptTouchEvent(ev);
} 

In onInterceptTouchEvent() calculate if the ListView has scrolled totally to the top or bottom. If it is somewhere in between then ask the parent to not intercept touches.

To check for top or bottom try:

int scrollRange = computeVerticalScrollRange();
int scrollOffset = computeVerticalScrollOffset();
int scrollExtend = computeVerticalScrollExtent();
if(scrollOffset == 0){
    //AtTop
}else if(scrollRange == scrollOffset + scrollExtend){
    //AtBottom
}