Updating ListView:ArrayAdapter in a timer

Question

I am fairly new to android but not to programming. Have a good long years of embedded linux experience. What I am findin strange is that to do very simple tasks like updating a listview on a timer, I am not able to find any documentation and the source is so interleaved in pelothra of classes that I find it very strange to spend 2-3 days googling for a very basic thing updating a list in a timer. How hard it can be, but my bad luck I am not able to find a single sample for that..... Please Help.

What I trying to do is very simple, I am writing a Activity which has a timer, the timer reads a status value from a HTTP GET and displays it in a list.

First I created a ListView then attached an ArrayAdapter with 0 elements in that. In my timer I am doing the following

//Timer run code
public void run() {
    strng = GetStatus()         
    adapter.add(strng);
    adapter.notifyDataSetChanged();
}

But it is not at all working.

Can anyone please help me with a sample.... or someone at GOOGLE please put some samples of fairly basic things.

thanks

Answer 1

I managed to get it running though, here is a small code. Please have a look modify play with it. I would be creating a blog shortly to put these samples....

Now that it is working to very basic extent, If I would like to modify it (A) How hard / easy is to replace the string at a particular position in the adapter. Right Now I am using ArrayAdapter which does not have any replace function. Why :( ? (B) If I have to create a service and let my service update the String values[]. what is the way to do it ? I read about intents but as service and activity are in same app, cant there be global data ? (C) and a point about java/android, why do you write function definition is a new call. Isn't it hard to debug and incorrect way to code ?

public class ScreenOne extends Activity {
protected ListView mylist;
protected ArrayList<String> strlist;
protected ArrayAdapter<String> adapter;
protected TimerTask ttask;
protected int ctr =0;
protected Timer timer;

protected String[] values = new String[] { "XYAndroid", "iPhone", "WindowsMobile",
        "Blackberry", "WebOS", "Ubuntu", "Windows7", "Max OS X",
        "Linux", "OS/2", "Ubuntu", "Windows7", "Max OS X", "Linux",
        "OS/2", "Ubuntu", "Windows7", "Max OS X", "Linux", "OS/2",
        "Android", "iPhone", "WindowsMobile" };
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_screen_one);

    mylist = (ListView) findViewById(R.id.s1ListView);
    strlist = new ArrayList<String>();

    adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, strlist);

    mylist.setAdapter(adapter);


    Timer t = new Timer();
    //Set the schedule function and rate
    t.scheduleAtFixedRate(
            new TimerTask() 
            {

                @Override
                public void run()
                {
                    runOnUiThread(
                            new Runnable() {

                                @Override
                                public void run() {

                                    if(ctr  < values.length) {
                                        adapter.add(values[ctr]);
                                        ctr++;

                                    }
                                }
                            });

                }
            }
            ,
            0,
            500);
}