CODEWITHSUNDEEP
androidlistviewonscroll
Edmund Rojas
Edmund Rojas

Reputation: 6606

Android List OnScrollListener how to detect everytime a new List item is visible in either direction

Learning how to use the OnScrollListener and I want to make a way I can detect everytime a new List item is visible when a user scrolls up or down in a listview, if the user scrolls down I want to make a counter increment by 1 for each new cell that enters the screen and if it scrolls up I want it to decrement, any help would go a long way, thanks.

counter = 0;
    list.setOnScrollListener(new OnScrollListener() {
        public void onScrollStateChanged(AbsListView view, int scrollState) {

        }

        public void onScroll(AbsListView view, int firstVisibleItem,
                int visibleItemCount, int totalItemCount) {

            // If list scroll up
            counter++;

            // If list scrolls down
            counter--;

        }
    });

Upvotes: 3

Views: 5300

Answers (2)

Edmund Rojas
Edmund Rojas

Reputation: 6606

I figured it out, the first visible item increments by one as you scroll down

counter = 0;
    list.setOnScrollListener(new OnScrollListener() {
        public void onScrollStateChanged(AbsListView view, int scrollState) {
            // Do nothing
        }

        public void onScroll(AbsListView view, int firstVisibleItem,
                int visibleItemCount, int totalItemCount) {

            if(firstVisibleItem > counter + 3 || firstVisibleItem < counter - 3){
                counter = firstVisibleItem;
                Toast.makeText(ListTestActivity.this,
                        "counter = " + counter,
                        Toast.LENGTH_LONG).show();
            }



        }
    });

Upvotes: 3

Khantahr
Khantahr

Reputation: 8548

Use the firstVisibleItem variable. When it changes, adjust your count appropriately.

Upvotes: 1

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