Using Loader in API 8

Question

I'm following the tutorial from Lars Vogella: http://www.vogella.com/articles/AndroidSQLite/article.html#todo

But I want it to work on API 8. I got it working on API 11+ and did the following to get it working on API 8. At Android Tools I added a support Library and I added the following imports:

import android.support.v4.app.ListFragment;
import android.support.v4.app.LoaderManager;
import android.support.v4.content.CursorLoader;
import android.support.v4.content.Loader;
import android.support.v4.widget.CursorAdapter;
import android.support.v4.widget.SimpleCursorAdapter;

But still Eclipse gives me the error:

The method getLoaderManager() is undefined for the type TodosOverviewActivity

In the method:

private void fillData() {

    // Fields from the database (projection)
    // Must include the _id column for the adapter to work
    String[] from = new String[] { TodoTable.COLUMN_SUMMARY };
    // Fields on the UI to which we map
    int[] to = new int[] { R.id.label };

    getLoaderManager().initLoader(0, null, this);
    adapter = new SimpleCursorAdapter(this, R.layout.todo_row, null, from,
        to, 0);

    setListAdapter(adapter);
  }

Can anybody shine some light on this error?

---

I found the following 'solution' but I'm not sure how to implement this in the tutorial, is this the solution for having the getSupportLoaderManager() and ListView related methods available and if so, how do I implement this correctly?:

public class TodosOverviewActivity extends FragmentActivity {

public static class TodosOverviewListFragment extends ListFragment
        implements LoaderManager.LoaderCallbacks<Cursor> {

---

The total Class:

public class TodosOverviewActivity extends FragmentActivity implements
    LoaderManager.LoaderCallbacks<Cursor> {
  private static final int ACTIVITY_CREATE = 0;
  private static final int ACTIVITY_EDIT = 1;
  private static final int DELETE_ID = Menu.FIRST + 1;
  // private Cursor cursor;
  private SimpleCursorAdapter adapter;


/** Called when the activity is first created. */

  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.todo_list);
    this.getListView().setDividerHeight(2);
    fillData();
    registerForContextMenu(getListView());
  }

  // Create the menu based on the XML defintion
  @Override
  public boolean onCreateOptionsMenu(Menu menu) {
    MenuInflater inflater = getMenuInflater();
    inflater.inflate(R.menu.listmenu, menu);
    return true;
  }

  // Reaction to the menu selection
  @Override
  public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
    case R.id.insert:
      createTodo();
      return true;
    }
    return super.onOptionsItemSelected(item);
  }

  @Override
  public boolean onContextItemSelected(MenuItem item) {
    switch (item.getItemId()) {
    case DELETE_ID:
      AdapterContextMenuInfo info = (AdapterContextMenuInfo) item
          .getMenuInfo();
      Uri uri = Uri.parse(MyTodoContentProvider.CONTENT_URI + "/"
          + info.id);
      getContentResolver().delete(uri, null, null);
      fillData();
      return true;
    }
    return super.onContextItemSelected(item);
  }

  private void createTodo() {
    Intent i = new Intent(this, TodoDetailActivity.class);
    startActivityForResult(i, ACTIVITY_CREATE);
  }

  // Opens the second activity if an entry is clicked
  @Override
  protected void onListItemClick(ListView l, View v, int position, long id) {
    super.onListItemClick(l, v, position, id);
    Intent i = new Intent(this, TodoDetailActivity.class);
    Uri todoUri = Uri.parse(MyTodoContentProvider.CONTENT_URI + "/" + id);
    i.putExtra(MyTodoContentProvider.CONTENT_ITEM_TYPE, todoUri);

    // Activity returns an result if called with startActivityForResult
    startActivityForResult(i, ACTIVITY_EDIT);
  }



  private void fillData() {

    // Fields from the database (projection)
    // Must include the _id column for the adapter to work
    String[] from = new String[] { TodoTable.COLUMN_SUMMARY };
    // Fields on the UI to which we map
    int[] to = new int[] { R.id.label };

    getSupportLoaderManager().initLoader(0, null, this);
    adapter = new SimpleCursorAdapter(this, R.layout.todo_row, null, from,
        to, 0);

    setListAdapter(adapter);
  }

  @Override
  public void onCreateContextMenu(ContextMenu menu, View v,
      ContextMenuInfo menuInfo) {
    super.onCreateContextMenu(menu, v, menuInfo);
    menu.add(0, DELETE_ID, 0, R.string.menu_delete);
  }

  // Creates a new loader after the initLoader () call
  @Override
  public Loader<Cursor> onCreateLoader(int id, Bundle args) {
    String[] projection = { TodoTable.COLUMN_ID, TodoTable.COLUMN_SUMMARY };
    CursorLoader cursorLoader = new CursorLoader(this,
        MyTodoContentProvider.CONTENT_URI, projection, null, null, null);
    return cursorLoader;
  }

  @Override
  public void onLoadFinished(Loader<Cursor> loader, Cursor data) {
    adapter.swapCursor(data);
  }

  @Override
  public void onLoaderReset(Loader<Cursor> loader) {
    // data is not available anymore, delete reference
    adapter.swapCursor(null);
  }

} 

Answer 1

The problem is that you're extending 'ListActivity' instead of 'ListFragment'.

If you leverage a ListFragment, you'lll get access to getLoaderManager() from the support library.

public class TodosOverviewActivity extends ListFragment {
  private void fillData() {
    getLoaderManager().initLoader(...);
  }
}

Answer 2

TodosOverviewActivity should extend FragmentActivity and you should use getSupportLoaderManager()