Android does not append() text to textview properly

Question

I have a textview in which i append text in two ways: First way: by clicking button and getting what is in EditText.

 sendbutton.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
              txview.append("Text: "+txedit.getText()+"\n");
              txedit.setText("");

 }
          });

And this works fine, when i click the button textview updates the view with new text.

BUT

The second way, I listen to xmpp listener (asmack library) and on recieving message I append it to textView.

 chat = xmpp.getChatManager().createChat(contactid[1], new MessageListener() {
                public void processMessage(Chat chat, Message message) {    
                     try {
                        chat.sendMessage(message.getBody());
                    } catch (XMPPException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }                txview.append("Text"+message.getFrom()+"\n"+message.getBody()+"\n");               }                                                       }
            );;

The Problem is, that i recieve message, i know it for sure (because i resend it to user with chat.sendMessage(message.getBody());), BUT textview shows my messages only after I change the view or get application to background (clicking home button) and then getting it back to the front.

What I tried calling invalidate() on every view, doesn't work at all.

Is it any solution or an other way to do what im doing?

Answer 1

You can achieve posting on GUI thread by doing following trick. Pass your context (Activity or Service) to your listener. Inside listener:

Handler h = new Handler(context.getMainLooper());

h.post(new Runnable() {
    @Override
    public void run() {
         txview.append("Text"+message.getFrom()+"\n"+message.getBody()+"\n"); 
    }
});

Answer 2

Are you sure that in the second example the processMessage(Chat, Message) method is invoked on a GUI thread? If not, there is your problem. Never touch GUI from a non-GUI thread. Almost no GUI likes that.