How to syncronisize two Listview positions

Question

I have two ListViews. Is there any way to synchronize the position of ListViews when I scroll any one of the Lists. Im implementing an AbsLis

Answer 1

Here is a working code sample of what nininho is suggesting

MainActivity

public class MainActivity extends Activity {

public static String[] Cheeses = new String[] { "Abbaye de Belloc", "Abbaye du Mont des Cats",
        "Abertam", "Abondance", "Ackawi", "Acorn", "Adelost", "Affidelice au Chablis",
        "Afuega'l Pitu", "Airag", "Airedale", "Aisy Cendre", "Allgauer Emmentaler", "Alverca",
        "Ambert", "American Cheese", };

ListView list1;
ListView list2;

boolean isLeftListEnabled = true;
boolean isRightListEnabled = true;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    ListAdapter adapter = new ArrayAdapter(this, android.R.layout.simple_list_item_1,
            Cheeses);

    list1 = (ListView) findViewById(R.id.list1);
    list1.setAdapter(adapter);

    list2 = (ListView) findViewById(R.id.list2);
    list2.setAdapter(adapter);

    // IF YOU DO NOT OVERRIDE THIS
    // ONLY THE ONE THAT IS TOUCHED WILL SCROLL OVER
    list1.setOverScrollMode(ListView.OVER_SCROLL_NEVER);
    list2.setOverScrollMode(ListView.OVER_SCROLL_NEVER);

    list1.setOnScrollListener(new OnScrollListener() {

        @Override
        public void onScrollStateChanged(AbsListView view, int scrollState) {
            // onScroll will be called and there will be an infinite loop.
            // That's why i set a boolean value
            if (scrollState == SCROLL_STATE_TOUCH_SCROLL) {
                isRightListEnabled = false;
            } else if (scrollState == SCROLL_STATE_IDLE) {
                isRightListEnabled = true;
            }
        }

        @Override
        public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount,
                int totalItemCount) {
            View c = view.getChildAt(0);
            if (c != null && isLeftListEnabled) {
                list2.setSelectionFromTop(firstVisibleItem, c.getTop());
            }
        }
    });

    list2.setOnScrollListener(new OnScrollListener() {
        @Override
        public void onScrollStateChanged(AbsListView view, int scrollState) {
            if (scrollState == SCROLL_STATE_TOUCH_SCROLL) {
                isLeftListEnabled = false;
            } else if (scrollState == SCROLL_STATE_IDLE) {
                isLeftListEnabled = true;
            }
        }

        @Override
        public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount,
                int totalItemCount) {
            View c = view.getChildAt(0);
            if (c != null && isRightListEnabled) {
                list1.setSelectionFromTop(firstVisibleItem, c.getTop());
            }
        }
    });
}
}

the XML