Updating a list after a child process has finished

Question

The main activity of the application is to display a list. The user clicks on something on the list which opens a edit screen. Upon fisnish, the edit screen is closed - and I want the original list to be updated with whatever hapenned on the edit screen. I save the data to a file - and I can just read it again to update the list. However I don't know where to insert the re-read code.

In the ListActivity - what method is called whe the list gets focus again?

This is my main List activity code:

Creating the view:

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

    // Inflate our UI from its XML layout description.
    setContentView(R.layout.my_activity);

   list=new Data_List(this);  // my data reading class
   list.read_data();           // reads from a file

  load_dynamic_list();

}

Loading the data:

private void load_dynamic_list(){
             ladapter=new         
list_adapter(this,android.R.layout.simple_list_item_1,list);  // the type is actually  ignored                                                                                  // getview function in list_adapter handles everything
          setListAdapter(ladapter);
         this.getListView().invalidate();

}

Something was selected:

protected void onListItemClick (ListView l, View v, int position, long id){
  int a;
   intent = new Intent(this,Editing.class);

        intent.putExtra("New_entry",0);
        intent.putExtra("Entry",position);


        //start the second Activity
        this.startActivity(intent);


 }

In the Editing function I end off like this:

    @Override
public void onClick(View v) {
    // TODO Auto-generated method stub
    if(v.getId() == R.id.button_save){
        do_save();  // saves to a file

  //  I want something like: caller.getListView().invalidate();

         finish();
                    }
    if(v.getId() == R.id.button_cancel){
        finish();
                    }
}

What method can I override or call that will execute when the editing is done? At that point I want to read_data() and then load_dynamic_list() again.

Answer 1

You have to use AsyncTask.

Prefer URL :

http://steveliles.github.com/android_s_asynctask.html http://www.vogella.com/articles/AndroidPerformance/article.html

With example :

http://labs.makemachine.net/2010/05/android-asynctask-example/

Answer 2

 @Override
 protected void onResume() {
      super.onResume();

     list=new Data_List(this);
     list.read_data();
           load_dynamic_list();    // becuase whatever was edited needs to be reread. 

}