Question

Guess that I have a TextView that I want to update it in some situations. I want to have a thread that every one or two seconds checks the circumstances and updates TextView’s text if necessary.
Any Idea?

Answer 1

You can use Handler, in your GUI:

Handler hnd = new Handler() {
    public void handleMessage(Message msg) {
        if ( msg.what == 101 ) {
           //update textview
        }
    }
}

pass hnd to your thread, and in your thread do:

Message m = new Message();
m.what = 101;
hnd.sendMessage(m);

this assumes that in your separate thread you are doing some work that needs reporting to GUI thread, you can also send text messages