import android.content.Intent;
import android.os.Bundle;
import android.widget.TabHost;
 
public class Main extends TabActivity{
 
	public TabHost tabHost;
 
	public void onCreate(Bundle savedInstanceState) {
	    super.onCreate(savedInstanceState);
	    setContentView(R.layout.main);
 
            // Get the tabHost
	    this.tabHost = getTabHost();
 
	    TabHost.TabSpec spec;  // Resusable TabSpec for each tab
	    Intent intent;  // Reusable Intent for each tab
 
	    // Create an Intent to launch the first Activity for the tab (to be reused)
	    intent = new Intent().setClass(this, ListViewGroup.class);
 
	    // Initialize a TabSpec for the first tab and add it to the TabHost
	    spec = tabHost.newTabSpec("ListViewGroup").setIndicator("ListViewGroup",
	    		getResources().getDrawable
	    				(null)) // Replace null with R.drawable.your_icon to set tab icon
	    				.setContent(intent);
	    tabHost.addTab(spec);
 
            // Create an Intent to launch an Activity for the tab (to be reused)
	    intent = new Intent().setClass(this, SecondActivityGroup.class);
 
	    // Initialize a TabSpec for the second tab and add it to the TabHost
	    spec = tabHost.newTabSpec("SecondGroup").setIndicator("SecondGroup",
	    		getResources().getDrawable
	    				(null)) // Replace null with R.drawable.your_icon to set tab icon
	    				.setContent(intent);
	    tabHost.addTab(spec);
 
	    tabHost.setCurrentTab(0);
	}

import java.util.ArrayList;
import android.app.ActivityGroup;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
 
public class ListViewGroup extends ActivityGroup {
 
        // Keep this in a static variable to make it accessible for all the nesten activities,
 //lets them manipulate the view
	public static ListViewGroup group;
 
        // Need to keep track of the history if you want the back-button to
// work properly, don't use this if your activities requires a lot of memory.
	private ArrayList<View> history;
 
	@Override
	protected void onCreate(Bundle savedInstanceState) {
	      super.onCreate(savedInstanceState);
	      this.history = new ArrayList<View>();
	      group = this;
 
              // Start the root activity withing the group and get its view
	      View view = getLocalActivityManager().startActivity("ListView", new
	    	      							Intent(this,ListView.class)
	    	      							.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP))
	    	                                .getDecorView();
 
              // Replace the view of this ActivityGroup
	      replaceView(view);
 
	   }
 
	public void replaceView(View v) {
                // Adds the old one to history
		history.add(v);
                // Changes this Groups View to the new View.
		setContentView(v);
	}
 
	public void back() {
		if(history.size() > 0) {
			history.remove(history.size()-1);
			setContentView(history.get(history.size()-1));
		}else {
			finish();
		}
	}
 
   @Override
    public void onBackPressed() {
    	ListViewGroup.group.back();
        return;
    }
 
}

import android.app.ListActivity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.ListAdapter;
import android.widget.ListView;
 
public class ListView extends ListActivity{
 
       // Data to put in the ListAdapter
       private String[] cities = new String[] {"Rome", "Budapest", "Washington"}
    	private ListAdapter adapter;
 
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.listview);
        fillData();
    }
 
    // Fill the list with some data, this can be anything really
    public void fillData() {
    	ArrayAdapter citiesAdapter = new ArrayAdapter(this, R.layout.city_row, cities);
        setListAdapter(citiesAdapter);
    }
 
    @Override
    protected void onListItemClick(ListView l, View v, int position, long id) {
    	super.onListItemClick(l, v, position, id);
 
        Intent i = new Intent(this, ShowCity.class);
        String city_name = (String) getListAdapter().getItem(position);
        i.putExtra("city_name", city_name);
 
        // Create the view using FirstGroup's LocalActivityManager
        View view = FirstGroup.group.getLocalActivityManager()
        .startActivity("show_city", i
        .addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP))
        .getDecorView();
 
        // Again, replace the view
        FirstGroup.group.replaceView(view);
    }
}