Expand group row programmatically in expandable list

Question

I am using expandablelistview. Is there anyway I can expand the group row when an image inside is clicked? I know that to have the image respond to click, I have to set its focus. Now, once this image responds to click (inside my custome adapter), how can I programmatically expand/collapse that specific group row it belongs to?

Thank you

Answer 1

In adapter

private OnItemSelectedListener onItemSelectedCallback;

public interface OnItemsSelectedListener {
    public void onImageSelected(int groupPos);
}

public YourAdapter(Context context) {
    try {
        this.onItemSelectedCallback = (OnItemSelectedListener ) context;
    }
    catch (ClassCastException e) {
        throw new ClassCastException(context.toString() + " must implement OnItemSelectedListener ");
    }
}

Add this in getView()

ImageView imageView = new ImageView();
imageView.setTag(R.id.tagGroupPosition, groupPosition);
imageView.setOnClickListener(onClickListener);

Add this in OnClickListener

OnClickListener onClickListener = new OnClickListener() {
    @Override
    public void onClick(View v) {
        int groupPos = ((ImageView) v).getTagId(R.id.tagGroupPosition);
        onItemSelectedCallback.onImageSelected(groupPos);
    }
}

Then in activity you have to implements YourAdapter.OnItemsSelectedListener the Override onImageSelected

@Override
public void onImageSelected(int groupPos){
    if(expandableList.isGroupExpanded(groupPos)){
        expandableList.collapseGroup(groupPos);
    }else{
        expandableList.expandGroup(groupPos);
    }
}

Answer 2

A simpler way:

1. Pass a reference to the ExpandableListView in the adapter constructor;
2. in getGroupView add an OnClickListener on the button you need and simply call listView.expandGroup(position);

Example:

public class YourAdapter extends BaseExpandableListAdapter {

private ExpandableListView listView;

public ReportsAdapter(ExpandableListView listView) {
    this.listView = listView;
}

//...

@Override
public View getGroupView(final int position, boolean isExpanded, View convertView, ViewGroup parent) {
    ParentViewHolder holder;

    if (convertView == null) {
        convertView = LayoutInflater.from(parent.getContext())
                .inflate(R.layout.your_item, parent, false);

        holder = new ParentViewHolder();

        //... holder logic


        holder.btnExpand = convertView.findViewById(R.id.btn_expand);

        convertView.setTag(holder);
    } else {
        holder = (ParentViewHolder) convertView.getTag();
    }

    //..holder logic

    holder.btnExpand.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            listView.expandGroup(position);
        }
    });

    return convertView;
}

In your Activity onCreate() or Fragment onCreateView() have

ExpandableListView listView = (ExpandableListView) view.findViewById(R.id.expandable_list_view);
    mAdapter = new YourAdapter(listView);
    listView.setAdapter(mAdapter);