add imagebutton to one fragment from another fragment

[M Lee]

I have two classes. One extends FragmentActivity (MainActivity.java) and the other extends Fragment (HomeFragment.java). What I want is to create an image button in MainActivity and put it in home_fragment.xml and then update HomeFragment.java so that my imagebutton is permanently in the layout. Right now, I have a button, and add it to home_fragment.xml, and that works fine, but then if I leave that fragment and return back to it (through a button click), the button disappears.

MainActivity is running a separate thread and listening on a port for an incoming image. Once it gets this image it creates an imagebutton with the image as the background. It adds this image button to an xml layout (home_fragment). This is all working correctly and this is the code I have for MainActivity:

private void RepeatTask()
{
  repeatTaskThread = new Thread()
  {
     public void run()
     {
        while (true)
        {


           try {


              System.out.println("TRY_1");

              Socket socket = new Socket("72.120.55.34", 5050);

              // Get data sent through socket
              DataInputStream DIS = new DataInputStream(socket.getInputStream());

              System.out.println("DataInputStream Started");

              // read data that got sent
              String applicationName = DIS.readUTF();


              // read array data for bitmap

              int len = DIS.readInt();
              byte[] data = new byte[len];

              DIS.readFully(data, 0, data.length);


               Bitmap bitmap = BitmapFactory.decodeByteArray(data, 0, data.length);
               final Drawable d = new BitmapDrawable(getResources(), bitmap);



              runOnUiThread(new Runnable() {
                 @Override
                 public void run() {
                    // TODO Auto-generated method stub


                    Log.d("tag_name", "Try_2");


                    ImageButton btn = new ImageButton(getApplicationContext());
                    //btn.setId(1);
                    btn.setBackgroundDrawable(d);
                    Log.d("tag_name", "Create Button" + btn);

                    ViewGroup RelativeLayout = (ViewGroup) findViewById(R.id.home_fragment);
                    btn.setLayoutParams(new ViewGroup.LayoutParams(ViewGroup.LayoutParams.FILL_PARENT,
                            ViewGroup.LayoutParams.WRAP_CONTENT));

                    RelativeLayout.addView(btn);
                    Log.d("tag_name", "Button Added to View" + RelativeLayout);


                    btn.setOnClickListener(new View.OnClickListener() {

                       @Override
                       public void onClick(View v) {



                       }
                    });


                 }
              });



              socket.close();


           } catch (Exception e) {


              System.out.println("Exception is "+e.toString());

           }



           try
           {
              // Sleep for 5 seconds
               Thread.sleep(5000);
           }
           catch (Exception e)
           {
              e.printStackTrace();
           }
        }
     };
  };
  repeatTaskThread.start();
}

Now, how to I get this image button to update in HomeFragment? And is this even what I should be doing? I just need my image button to now always appear whenever other parts of my code call on HomeFragment.

If I try to use Otto to update by HomeFragment I think I add this to my HomeFragment:

public static Bus bus = new Bus(ThreadEnforcer.ANY);




Add this to my OnCreateView of HomeFragment:

 bus.register(this);




And create a subscribe method to receive updates from Main:

 @Subscribe
public void onCustomButtonEvent(Drawable d) {
    // ...
}

Now I have to add a @produce method to Main. But I am unsure how to do this? I tried wrapping it around different parts of my code and passing my Drawable through, but with no luck. Also if I don't create my button in "runOnUiThread" I get errors.

Thank you very much for a pointer :)