Where would I place requery() in order to refresh the list when I add new task from another tab?

Question

I am making a very simple dump and display app. I would like to see my newly entered data displayed on the list found on the first tab. But I don't know where to place requery();

Here is the code for the first tab. (Displays the data from DB.)

public class ListTask extends ListActivity{

@Override   
public void onCreate(Bundle savedInstanceState){
    super.onCreate(savedInstanceState);

    setContentView(R.layout.list_task);
    SQLiteDatabase db = openOrCreateDatabase("db_alist", 0, null);
    db.execSQL("CREATE TABLE IF NOT EXISTS tbl_alist (_id INTEGER PRIMARY KEY AUTOINCREMENT, task_name VARCHAR, task_date DATE, task_details VARCHAR);");
    Cursor c = db.rawQuery("SELECT _id, task_name, task_date FROM tbl_alist", null);
    while(c.moveToNext()){
        c.getString(c.getColumnIndex("task_name"));
        c.getString(c.getColumnIndex("task_date"));
    }
    db.close();
    String[] displayfields = new String[] {"task_name", "task_date"};
    int[] displayviews = new int[] {android.R.id.text1, android.R.id.text2};
    SimpleCursorAdapter sca = new SimpleCursorAdapter(this, android.R.layout.simple_list_item_2, c, displayfields, displayviews);
    this.setListAdapter(sca);
}
@Override
public void onResume(){
    super.onResume();
    System.out.println("Resume?");
}
@Override
public void onPause(){
    super.onPause();
    System.out.println("Paused?");
}}

I have tried doing (pseudo codes only)

public class{
Cursor c

 public void onCreate(){
 ...
 }

 public void onResume(){
 super.onResume();
 c.requery();
 }
}

and

public class{
SimpleCursorAdapter sca

 public void onCreate(){
 ...
 }

 public void onResume(){
 super.onResume();
 sca.notifyDataSetChanged();
 }
}

But BOTH don't work! Something is still wrong.

Answer 1

I guess onResume() will do.

This is always called immediately before the Activity becomes visible. So it is the logical place.

Promote the SimpleCursorAdapter sca to a member variable and in the onResume() method, call sca.notifyDataSetChanged()

Answer 2

Finally solved my own problem.

I needed to deactivate the cursor in onPause() then call requery in onResume!

It worked. :D

Answer 3

Why don't you create a ContentProvider ? With managedQuery and a ContentProvider, it would be transparent