ExpandableLists in Android, I want to allow only one parent list to expand at a time

Question

I want to make only one item in the parent list expand at a time, my code for the onCreate is currently the following. (It works as I want, But the method to allow only one pare

Answer 1

I believe a straight forward solution would be to implement one Adapter to handle any of the events you are interested in.

public class MyExpandableListAdapter extends SimpleExpandableListAdapter {

  public Activity mActivity;

  public MyExpandableListAdapter([ARGS USED IN QUESTION], Activity activity) {super([ARGS USED IN QUESTIONS]); mActivity = activity; }

  // then just override the method
  public void onGroupExpanded(int groupPosition) {
    int len = super.getGroupCount();
    ExpandableListView list = (ExpandableListView) mActivity.findViewById(R.id.list);
    for (int i = 0; i < len; i++) {
        if (i != groupPosition) {
            list.collapseGroup(i);
        }
    }
  }
}

By separating the list adapter into another class you will not clutter the Activity code with one-off listener implementations. Instead, in each Activity simply instantiate the adapter and set it on the list

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    // No try catch needed
    MyExpandableListAdapter mAdapter = new MyExpandableListAdapter([ARGS SHOWN IN QUESTION], MainActivity.this);

    ExpandableListView epView = (ExpandableListView) findViewById(R.id.list);
    epView.setAdapter(mAdapter);

    return true;
}