触摸cutom视图时不要滚动ListView

Question

I've created a custom view on which you can draw a path with your finger. It extends View class.

When I use it inside a ListView as one of its items if a user touches custom view the ListView is scrolled. How can I prevent this from happening?

I suppose I need to get focus somehow on my custom view. But I don't know how.

Update:

I found possible solution. In my custom view's onTouchEvent(Motion event) method I've placed getParent().requestDisallowInterceptTouchEvent(true); .

Without this the event queue when user touches custom view looked like this:

1. MotionEvent.ACTION_DOWN
2. MotionEvent.ACTION_MOVE
3. MotionEvent.ACTION_MOVE
4. MotionEvent.ACTION_CANCEL

When I receive MotionEvent with code MotionEvent.ACTION_CANCEL the ListView starts to scroll.

Answer 1

Setting requestDisallowInterceptTouchEvent(true) within child's onTouch(View, MotionEvent) method works:

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {

        ViewGroup item = (ViewGroup) inflater.inflate(R.layout.list_item, null);
        Button button = (Button)item.findViewById(R.id.list_item_btn);
        button.setText("button " + position);

        button.setOnTouchListener(new OnTouchListener() {

            @Override
            public boolean onTouch(View v, MotionEvent event) {
                listView.requestDisallowInterceptTouchEvent(true);
                return false;
            }

        });

        return item;
    }

Answer 2

I think u should also extend the ListView widget .

As u say ,when u touch the custom view ,the listview will scroll.
when u touch the custom view, the touch event will dispatch along the view hierarchy ,
I think listview may eat the touch event.
so ur customview can not receive the touch event.
if ur have not understand the dispatch of the touch event.
u can read this Managing Touch Events in a ViewGroup

at last.
I suggest u extend the ListView and override the onInterceptTouchEvent() method.
u can decide if ur ListView want to handle the touch event in the onInterceptTouchEvent() .
when u judge the touch should be handle by the drawPathView,
u can let the ListView dont intercept it.
so ur drawPathView can get the toch event .
and also the listView will not scroll