Hide custom search bar if all items in adapter are showing

Question

The problem I have is that listView.getLastVisiblePosition always returns -1 so I can\'t hide the searchView. I check this right after setting the

Answer 1

You can refer to my answer here Strange problem with broadcast receiver in Android not exactly the same but you can get the idea why your code not working.

To make it more clear, when you set the adapter to the ListView, nothing has been drawn yet and the method getLastVisiblePosition() can only return the correct value after the listview finish drawing all of it's visible children and know which one is the last visible one.

So, the most appropriate approach I can suggest here is trigger a callback after the listView finished drawing and we get the correct value then.

The ListView with listener after drawing:

static class MyListView extends ListView {
        private OnDrawCompletedListener mOnDrawCompletedListener;

        public MyListView(Context context) {
            super(context);
        }

        @Override
        protected void onDraw(Canvas canvas) {
            super.onDraw(canvas);
            if (mOnDrawCompletedListener != null) {
                mOnDrawCompletedListener.onDrawCompleted();
            }
        }

        public void setOnDrawCompletedListener(OnDrawCompletedListener listener) {
            mOnDrawCompletedListener = listener;
        }

        public static interface OnDrawCompletedListener {
            public void onDrawCompleted();
        }
    }

The sample code for getting last visible position

mListView.setAdapter(new EfficientAdapter(this));
//Will get -1 here
Log.e("Question-17953268",
        "getLastVisiblePosition  = "
                + mListView.getLastVisiblePosition());

mListView.setOnDrawCompletedListener(new OnDrawCompletedListener() {

    @Override
    public void onDrawCompleted() {
        //Will get correct value here
        Log.e("Question-17953268",
                "getLastVisiblePosition  = "
                        + mListView.getLastVisiblePosition());
    }

});