Rben Rben - 24 days ago 7
Android Question

Updating background of ListView Items when Adapter data changes

I have an application which lists items in a ListFragment. Each item has a different background color based on the item status. The adapter is subclassed from a SimpleCursorAdapter, because the items are stored in SQL. The editing of these items takes place in a different fragment. When the status is changed, I use an AsyncTask to trigger notifyDataSetChanged() on the Adapter on the GUI thread. But my list is not updating.

I know that I'm on the GUI thread because I overrode the notifyDataSetChanged class in order to check. The same traces also tell me I'm reaching the routine.:

@Override
public void notifyDataSetChanged() {
String tag = TAG + ".notifyDataSetChanged()";
Log.d(tag,"DATA SET CHANGE NOTIFICATION!");
if (Looper.getMainLooper().getThread() == Thread.currentThread()) {
Log.d(tag,"On GUI thread!");
} else {
Log.d(tag,"NOT on GUI thread!");
}
super.notifyDataSetChanged();
}


I would appreciate any suggestions. Thank you for your time and interest.

Here's the whole Adapter:

public class OrderListAdapter extends SimpleCursorAdapter {

private static final String TAG = "OrderListAdapter";
Context _context = null;
int layoutResourceId = 0;

/**
* Constructor
* @param context - Context
* @param layout - Layout
* @param c - Cursor
* @param from - String array with column names
* @param to - Int array with destination field ids
* @param flags - Integer with flags
*/
public OrderListAdapter(Context context, int layout, Cursor c,
String[] from, int[] to, int flags) {
super(context, layout, c, from, to, flags);
_context = context;
}

/**
* This override version changes the color of the background of the
* row based on the order status.
*/
public View getView(int position, View convertView, ViewGroup parent) {
View view = super.getView(position, convertView, parent);

if (view == null) {
LayoutInflater inflater = ((Activity)_context).getLayoutInflater();
view = inflater.inflate(R.layout.fragment_order_list_row, null);
}
setRowColor(view);
return view;
}

private void setRowColor(View view) {
Cursor cursor = getCursor();
int col = cursor
.getColumnIndex(DBContract.DeliveryOrderTable.ENROUTE_FLAG);
String enroute_flag = cursor.getString(col);
col = cursor
.getColumnIndex(DBContract.DeliveryOrderTable.DELIVERED_DATETIME);
String deliveredDateStr = cursor.getString(col);
int bgColorId = 0;
if (!deliveredDateStr.equals("")) {
bgColorId = R.color.bg_status_delivered_color;
} else if (enroute_flag.startsWith("t") || enroute_flag.startsWith("y")) {
bgColorId = R.color.bg_status_enroute_color;
} else {
bgColorId = R.color.bg_status_assigned_color;
}
view.setBackgroundColor(_context.getResources().getColor(bgColorId));

} // setRowColor()

///// DEBUG

@Override
public void notifyDataSetChanged() {
String tag = TAG + ".notifyDataSetChanged()";
Log.d(tag,"DATA SET CHANGE NOTIFICATION!");
if (Looper.getMainLooper().getThread() == Thread.currentThread()) {
Log.d(tag,"On GUI thread!");
} else {
Log.d(tag,"NOT on GUI thread!");
}
super.notifyDataSetChanged();
}

} // class

Answer Source

You have to update the cursor using adapter.changeCursor when data changes. See this answer: https://stackoverflow.com/a/1986071/198996