Question

I have a ListView with a custom CursorAdapter. Between the parameter of CursorAdapter I have the theme, CursorAdapter set colors from passed theme.

private MyCustomAdapter mAdapter;

public void onCreate(Bundle savedInstanceState) {
    ListView lv = (ListView)findViewById(R.id.myList);
    mAdapter =  new MyCustomAdapter(
        this, 
        R.layout.my_list_row, 
        null, // cursor set later by cursorloader
        mTheme); //int selected theme
    lv.setAdapter(mAdapter);
}

User can change theme from preference, in onResume() I check if theme has been changed, in this case actually I repete the above code, creating a new MyCustomAdapter.

My question is: can I use the existent Adapter changing one parameter and updating it? For example when cursor change I use

mAdapter.swapCursor(cursor);

Answer 1

Set your theme in your getView() of Adapter,
then you can call

adapter.notifyDataSetChanged();

in onResume() of Activity
but make sure you set your theme as the way you set view data for individual row.

for example:

public View getView(int position, View convertView, ViewGroup parent) {
      ViewHolder holder = null;
      if (convertView == null) {
           convertView = mInflater.inflate(R.layout.item1, null);
           holder = new ViewHolder();
            convertView.setTag(holder);
      } else {
            holder = (ViewHolder)convertView.getTag();
      }
      // your data for row implementation goes here
      // and also your theme implementation goes here
      // maybe some Method to set Theme
      if(savedTheme == Constants.RED)
            Utils.setTheme(convertView, Constants.RED);
      else
            //Your other themes
      return convertView;
}

setTheme() may be a static method in your Utils class which sets the text color or background of your row. or you can set theme inside getView() also.