ListView after filtration should be empty, when I add non-existing string

Question

I have got an Activity with the list and EditText beneath it, Edit Text is for entering a string so that list will consists that string. ListView based on BaseAdapter, contains elements of type F.

public class lstAdaptF extends BaseAdapter implements Filterable {
Context ctx;
LayoutInflater lInflater;
ArrayList<F> objectsF;
ArrayList<F> origobjectsF;
...
private Filter FirmaBBFilter;

lstAdaptF(Context context, ArrayList<F> f) {
    ctx = context;
    objectsF = f;
    origobjectsF = f;
    lInflater = (LayoutInflater) ctx.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
...
@Override
public Filter getFilter() {
    if (FFilter == null)
        FFilter = new FFilter();
    return FFilter;
}

...
private class FFilter extends Filter {
    @Override
    protected FilterResults performFiltering(CharSequence constraint) {
        FilterResults results = new FilterResults();
        if (constraint == null || constraint.length() == 0) {
            //get all inital list
            results.values = origobjectsF;
            results.count = origobjectsF.size();
            Log.d("lstAdaptF","empty filter");
        } else {
            // We perform filtering operation
            ArrayList<F> nF = new ArrayList<F>();

            for (F p : origobjectsF) {
                if (p.getName().toUpperCase().contains(constraint.toString().toUpperCase())){
                    nF.add(p);

                }
            }
            results.values = nF;
            results.count = nF.size();
        }
        return results;
    }

Everithing works fine, for example list contains strings

Awork
Aworth
winter

I enter 'w': Awork, Aworth, winter

I enter 'wo': Awork, Aworth

I enter 'woo': Awork, Aworth - the list still the same, when it should be empty! How could I manage this situation? Thank you.

UPD:

@Override
    protected void publishResults(CharSequence constraint, FilterResults results) {
        // Now we have to inform the adapter about the new list filtered
        if (results.count == 0)
            notifyDataSetInvalidated();
        else {          
            objectsF = (ArrayList<F>) results.values;
            notifyDataSetChanged();

        }
    }

UPD2:

@Override
public Object getItem(int position) {
    return objectsF.get(position);
}

 @Override
public int getCount() {
    return objectsF.size();
} 
@Override
public View getView(int position, View convertView, ViewGroup parent) {

    View view = convertView;
    FHolder holder = new FHolder();

    if (view == null) {
        view = lInflater.inflate(R.layout.itemf, parent, false);
        TextView tvAF = (TextView) view.findViewById(R.id.tvA);
...
        holder.tvAF = tvAF;
...
        view.setTag(holder);
    }
    else 
        holder = (FHolder) view.getTag();

    F p = getF(position);
    holder.tvAF.setText(p.a + "");
    ..
    return view;
}

can you please post the getView , getCount, getItem methods ? they should point to the filtered results when they should be used. — android developer, Feb 16 '13 at 17:37
it looks something wrong with `notifyDataSetInvalidated()`. Try to remove this `if-else` and always call `objectsF = (ArrayList) results.values; notifyDataSetChanged();` — Vladimir Mironov, Feb 16 '13 at 17:45
you are right.. now it works fine. Whould it be right to leave things as it is? — Foenix, Feb 16 '13 at 17:53
@Foenix yes, it's ok, but I don't really understand why it is not working with `notifyDataSetInvalidated()` — Vladimir Mironov, Feb 16 '13 at 18:02
@Foenix, it's great you got it working. I've posted my comment as an answer so you can accept it — Vladimir Mironov, Feb 16 '13 at 18:12

score 1 · Accepted Answer · answered Feb 16 '13 at 18:12

It looks like something wrong with notifyDataSetInvalidated(). Try to remove this if-else:

@Override
protected void publishResults(CharSequence constraint, FilterResults results) {
    // Now we have to inform the adapter about the new list filtered       
    objectsF = (ArrayList<F>) results.values;
    notifyDataSetChanged();
}

ListView after filtration should be empty, when I add non-existing string

1 Answers1