Creating custom simple cursor adapter

Question

I want to create a very simple cursor custom cursor adapter to facilitate changing the colors of row items on click. Using the following code

private static int save = -1;

public void onListItemClick(ListView parent, View v, int position, long id) { 

    parent.getChildAt(position).setBackgroundColor(Color.BLUE);

    if (save != -1 && save != position){
        parent.getChildAt(save).setBackgroundColor(Color.BLACK);
    }

    save = position;                

}

I got the code from this thread https://stackoverflow.com/a/7649880/498449

I would have used a simple cursor adapter and placed the code in the onClick, but because the default list in the ListFragment reuses views, as you scroll multiple views are shown to be highlighted. Talking on IRC, it was suggested that I create a custom cursor adapter. However, I can't seem to locate the best practice how how to do this, and where the above code snippet would fit in. Could greatly appreciate the help.

public class AreaCursorAdapter extends CursorAdapter {
    private Context context;


    public AreaCursorAdapter(Context context, Cursor c) {
        super(context, c);
        // TODO Auto-generated constructor stub
    }

    @Override
public void bindView(View view, Context context, Cursor cursor) {
    TextView list_item = (TextView)view.findViewById(android.R.id.text1);
    list_item.setText(cursor.getString(cursor.getColumnIndex(INDICATOR_NAME)));

}

@Override
public View newView(Context context, Cursor cursor, ViewGroup parent) {
    LayoutInflater inflater = LayoutInflater.from(context);
    View v = inflater.inflate(android.R.layout.simple_list_item_1, parent, false);
    bindView(v, context, cursor);
    return v;
}

}

I've updated the cursor adapter with some code I found online. However, I have two problems. 1. I am using a cursor loader, so I don't have a "cursor" object to pass into the constructor. 2. I'm getting a warning from Eclipse that the constructor has been deprecated.

Answer 1

You should be able to do it about that way:

class YourListFragment extends ListFragmentOrSomethingElse {
    private AreaCursorAdapter mAdapter;

    @Override    
    public void onCreate() {
        mAdapter = new AreaCursorAdapter(this, null);
        setListAdapter(mAdapter);
    }

    @Override
    public void onListItemClick(ListView parent, View v, int position, long id) { 
        mAdapter.setSelectedPosition(position);
    }

    @Override
    public void onLoadFinished(Loader<Cursor> loader, Cursor cursor) {
        mAdapter.swapCursor(cursor);
        // should reset that here maybe
        mAdapter.setSelectedPosition(-1);
    }
}

public class AreaCursorAdapter extends CursorAdapter {
    private Context context;
    private int mSelectedPosition;
    LayoutInflater mInflater;

    public AreaCursorAdapter(Context context, Cursor c) {
        // that constructor should be used with loaders.
        super(context, c, 0);
        mInflater = LayoutInflater.from(context);
    }

    public void setSelectedPosition(int position) {
        mSelectedPosition = position;
        // something has changed.
        notifyDataSetChanged();
    }

    @Override
    public void bindView(View view, Context context, Cursor cursor) {
        TextView list_item = (TextView)view.findViewById(android.R.id.text1);
        list_item.setText(cursor.getString(cursor.getColumnIndex(INDICATOR_NAME)));
        int position = cursor.getPosition(); // that should be the same position
        if (mSelectedPosition == position) {
           view.setBackgroundColor(Color.RED);
        } else {
           view.setBackgroundColor(Color.WHITE);
        }
    }

    @Override
    public View newView(Context context, Cursor cursor, ViewGroup parent) {
        View v = mInflater.inflate(android.R.layout.simple_list_item_1, parent, false);
        // edit: no need to call bindView here. That's done automatically
        return v;
    }

}