Android ListView array index out of bounds after filter

Question

I think this is a question for experts.

I get calls to getView() with positon out of bounds from the ListView data list.
This happens when I use the Adapter filter. The filter publishResults() method populates the data with a filtered list which is smaller than the original list.
The error seems to occur when the new filtered list is shorter than the previous filtered list. I changed the code of getView() to return a dummy convertView when out of bounds, just to see how many such calls are issued.

These are the relevant code and the log messages I logged:

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        // No logs here to keep ListView performance good
        Log.d(TAG, "+ getView( position=" + position + ")");
        ViewHolder holder;

        if( position >= mData.size() ) {
            // This code allows to see how many bad calls I get
            Log.w(TAG, "position out of bounds!");
            convertView = mInflater.inflate(mLayout, parent, false);
            return convertView;
        }

        . . . // Normal getView code

        return convertView;
    }

In the filter (code copied as is from ArrayAdapter source code)

        @Override
        protected void publishResults(CharSequence constraint, FilterResults results) {
            Log.pe(TAG, "+ publishResults(constraint:" + constraint + ", results.count:" + results.count + ")");
            //noinspection unchecked
            mData = (ArrayList<String>) results.values;
            if (results.count > 0) {
                notifyDataSetChanged();
            } else {
                notifyDataSetInvalidated();
            }
            Log.px(TAG, "- publishResults()");
        }

The log file shows that after a filter with 7 results, comes a fitler with 3 results, but getView keeps getting calls for 7 items (I marked with *** the out of bounds calls):

02-26 05:31:55.986: D/ViewerActivity(22857): + onQueryTextChange(newText:log)
02-26 05:31:55.986: D/ViewerActivity(22857): - onQueryTextChange()
02-26 05:31:56.029: D/LogScreenAdapter(22857): + performFiltering(prefix:log)
02-26 05:31:56.113: D/dalvikvm(22857): GC_CONCURRENT freed 378K, 5% free 13577K/14215K, paused 0ms+1ms
02-26 05:31:56.153: D/LogScreenAdapter(22857): - performFiltering()
02-26 05:31:56.153: D/LogScreenAdapter(22857): + publishResults(constraint:log, results.count:7)
02-26 05:31:56.167: D/LogScreenAdapter(22857): - publishResults()
02-26 05:31:56.167: D/LogScreenAdapter(22857): + getView( position=0)
02-26 05:31:56.167: D/LogScreenAdapter(22857): + getView( position=0)
02-26 05:31:56.167: D/LogScreenAdapter(22857): + getView( position=0)
02-26 05:31:56.167: D/LogScreenAdapter(22857): + getView( position=1)
02-26 05:31:56.167: D/LogScreenAdapter(22857): + getView( position=2)
02-26 05:31:56.167: D/LogScreenAdapter(22857): + getView( position=3)
02-26 05:31:56.167: D/LogScreenAdapter(22857): + getView( position=4)
02-26 05:31:56.167: D/LogScreenAdapter(22857): + getView( position=5)
02-26 05:31:56.167: D/LogScreenAdapter(22857): + getView( position=6)
02-26 05:31:56.167: D/LogScreenAdapter(22857): + getView( position=0)
02-26 05:31:56.167: D/LogScreenAdapter(22857): + getView( position=1)
02-26 05:31:56.167: D/LogScreenAdapter(22857): + getView( position=2)
02-26 05:31:56.167: D/LogScreenAdapter(22857): + getView( position=3)
02-26 05:31:56.167: D/LogScreenAdapter(22857): + getView( position=4)
02-26 05:31:56.493: D/LogScreenAdapter(22857): + getView( position=5)
02-26 05:31:56.503: D/LogScreenAdapter(22857): + getView( position=6)
02-26 05:32:23.793: D/ViewerActivity(22857): + onQueryTextChange(newText:logs)
02-26 05:32:23.793: D/ViewerActivity(22857): - onQueryTextChange()
02-26 05:32:23.813: D/LogScreenAdapter(22857): + performFiltering(prefix:logs)
02-26 05:32:23.854: D/dalvikvm(22857): GC_CONCURRENT freed 383K, 5% free 13577K/14215K, paused 0ms+0ms
02-26 05:32:23.924: D/dalvikvm(22857): GC_CONCURRENT freed 388K, 5% free 13573K/14215K, paused 0ms+1ms
02-26 05:32:23.974: D/LogScreenAdapter(22857): - performFiltering()
02-26 05:32:23.983: D/LogScreenAdapter(22857): + publishResults(constraint:logs, results.count:3)
02-26 05:32:23.983: D/LogScreenAdapter(22857): - publishResults()
02-26 05:32:23.983: D/LogScreenAdapter(22857): + getView( position=0)
02-26 05:32:24.074: D/LogScreenAdapter(22857): + getView( position=0)
02-26 05:32:24.093: D/LogScreenAdapter(22857): + getView( position=0)
02-26 05:32:24.113: D/LogScreenAdapter(22857): + getView( position=1)
02-26 05:32:24.155: D/LogScreenAdapter(22857): + getView( position=2)
02-26 05:32:24.164: D/LogScreenAdapter(22857): + getView( position=3)
*** 02-26 05:32:24.193: W/LogScreenAdapter(22857): position out of bounds!
02-26 05:32:24.233: D/LogScreenAdapter(22857): + getView( position=4)
*** 02-26 05:32:24.263: W/LogScreenAdapter(22857): position out of bounds!
02-26 05:32:24.284: D/LogScreenAdapter(22857): + getView( position=5)
*** 02-26 05:32:24.313: W/LogScreenAdapter(22857): position out of bounds!
02-26 05:32:24.333: D/LogScreenAdapter(22857): + getView( position=6)
*** 02-26 05:32:24.343: W/LogScreenAdapter(22857): position out of bounds!
02-26 05:32:24.353: D/LogScreenAdapter(22857): + getView( position=0)
02-26 05:32:24.373: D/LogScreenAdapter(22857): + getView( position=1)
02-26 05:32:24.383: D/LogScreenAdapter(22857): + getView( position=2)
02-26 05:32:24.403: D/LogScreenAdapter(22857): + getView( position=3)
*** 02-26 05:32:24.413: W/LogScreenAdapter(22857): position out of bounds!
02-26 05:32:24.433: D/LogScreenAdapter(22857): + getView( position=4)
*** 02-26 05:32:24.443: W/LogScreenAdapter(22857): position out of bounds!
02-26 05:32:24.463: D/LogScreenAdapter(22857): + getView( position=5)
*** 02-26 05:32:24.475: W/LogScreenAdapter(22857): position out of bounds!
02-26 05:32:24.483: D/LogScreenAdapter(22857): + getView( position=6)
*** 02-26 05:32:24.503: W/LogScreenAdapter(22857): position out of bounds!
02-26 05:38:26.769: D/dalvikvm(22857): GC_CONCURRENT freed 316K, 5% free 13640K/14215K, paused 0ms+1ms

What you are seeing here, the publishResults() method did change mData from a list of 7 items to a shorter list of 3 items, see the code above, but the Adapter keeps getting getView() calls for the 7 items list, even that it is not longer there.
Note that notifyDataSetChanged() has been called with the new data assignment, so the ListView should be aware of the new list.

Answer 1

what are you returning in public int getCount() method of custom list view adapter?

You should return like mData != null? mData.size() : 0,

Position out of bond is getting due to may be you are returning size of list more than data to show in the list

getCount() method of custom list adapter specifies size of list view so it should be the size of data you are passing in the list

Answer 2

Seems like overriding of "getCount()" method will solve your problem:

@Override
public int getCount() {
    return mData.size();
}