Question

Is it possible to use a SectionIndexer with a GridView in Android? Fast scroll is working fine, and I’m using a custom adapter that extends BaseAdapter. The adapter is currently implementing SectionIndexer and seems to be identical to the examples shown online and on Stack Overflow. This made me think if it’s even possible to do with a GridView and a custom adapter.

Answer 1

static class YOUR_ADAPTER extends SimpleCursorAdapter implements SectionIndexer {

private AlphabetIndexer mIndexer;

 YOUR_ADAPTER (Context context, AlbumBrowserActivity currentactivity,
            int layout, Cursor cursor, String[] from, int[] to) {
        super(context, layout, cursor, from, to);

        getColumnIndices(cursor);
    } 

    private void getColumnIndices(Cursor cursor) {
        if (cursor != null) {
            YOUR_COLUMN = cursor.getColumnIndexOrThrow(WHAT_YOU'RE_SORTING);

            if (mIndexer != null) {
                mIndexer.setCursor(cursor);
            } else {
                mIndexer = new AlphabetIndexer(cursor, YOUR_COLUMN, mResources.getString(
                        R.string.fast_scroll_alphabet));
            }
        }
    }

    @Override
    public Object[] getSections() {
        return mIndexer.getSections();
    }

    @Override   
    public int getPositionForSection(int section) {
        return mIndexer.getPositionForSection(section);
    }

    @Override
    public int getSectionForPosition(int position) {
        return 0;
    }
}

fast_scroll_alphabet String

<string name="fast_scroll_alphabet">\u0020ABCDEFGHIJKLMNOPQRSTUVWXYZ</string>

That’s a basic example, but there’s not much more to it than that. Implementing SectionIndexer is pretty simple.