FragmentPagerAdapter implementing LoaderManager.LoaderCallbacks

Question

Im trying to implement a FragmentPagerAdapter with a cursor loader. However, it seems that I am unable to access the cursor within getItem() as I get a null reference error when attempting to access the cursor as it is not been set yet in onLoadFinished().

Will onLoadFinished() not complete until getItem() is finished?

Is there a better way to load the cursor data? I can query the ContentProvider directly and store the results in my cursor, but thought a loader is preferred.

public class MyAdapter extends FragmentPagerAdapter implements LoaderManager.LoaderCallbacks<Cursor>{

private Cursor cursor;


public MyAdapter(FragmentManager fm) {
    super(fm);
    getLoaderManager().initLoader(0, null, this);

}

@Override
public int getCount() {
    return 13;
}

@Override
public Fragment getItem(int position) {


    Bundle args = new Bundle();


    cursor.moveToPosition(position);
    args.putString(TextViewFragment.TITLE, cursor.getString(1));
    args.putInt(TextViewFragment.POSITION_KEY, position);
    return TextViewFragment.newInstance(args);

}

@Override
public CharSequence getPageTitle(int position) {
    return "Fragment # " + position;
}

@Override
public Loader<Cursor> onCreateLoader(int arg0, Bundle arg1) {
    // TODO Auto-generated method stub

    CursorLoader cursorLoader = new CursorLoader(getActivity(), TestContentProvider.CONTENT_URI, null, null, null, null);
    return cursorLoader;
}

@Override
public void onLoadFinished(Loader<Cursor> arg0, Cursor arg1) {
    // TODO Auto-generated method stub
    cursor = arg1;
    //throw new IllegalArgumentException("We are HEREHEREHEREHEREHEREHEREHEREHEREHEREHEREHEREHEREHEREHEREHEREHEREHEREHEREHEREHEREHEREHEREHERE");
}

@Override
public void onLoaderReset(Loader<Cursor> arg0) {
    // TODO Auto-generated method stub
}

}

}

score 1 · Answer 1 · answered Feb 26 '13 at 08:36

Have you tried putting the Loaders in the fragment instead of the adapter and probably a method to activate it. Try running the loaders in the activity and updating the ViewPager adapter using FragmentStatePageAdapter (works like a list adapater) instead of FragmentPagerAdapter.

FragmentPagerAdapter implementing LoaderManager.LoaderCallbacks

1 Answers1