Communication between TabActivity and the embedded activity
<p>I am trying to figure out the best practice of communication between a TabActivity and the child activity embedded in this TabActivity.</p>

<p>In my TabActivity, there is a button. When the button is clicked, I want the child activity embedded in this TabActivity to be updated. I wrote the code like below, and just wonder whether it is a good practice. Thanks.</p>

<p>MyTabActivity.java</p>

<pre><code>public class MyTabActivity extends TabActivity implements OnClickListener {
    private TabHost m_tabHost;

  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.ff_tab_activity);

    LayoutInflater inflater = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);

    m_tabHost = getTabHost(); 
    TabHost.TabSpec spec; 
    Intent intent; 

    intent = new Intent().setClass(this, ChildActivity.class);
    spec = m_tabHost.newTabSpec("Tab 1");
    spec.setContent(intent);
    tabView = (TextView) inflater.inflate(R.layout.tab_indicator, null);
    spec.setIndicator(tabView);
    m_tabHost.addTab(spec);

    m_tabHost.setCurrentTab(0);
    ImageView nextButtonIv = (ImageView) findViewById(R.id.next_button);
    nextButtonIv.setOnClickListener(this);
  }

  @Override
  public void onClick(View v) {
    switch (v.getId()) {
    case R.id.next_button:
        synchronized (ChildActivity.class) {
            if (null != ChildActivity.s_childActivity) {
                ChildActivity.s_childActivity.changeUI();
            }
        }
        break;
    }
}
</code></pre>

<p>ChildActivity.java</p>

<pre><code>public class ChildActivity extends Activity {
    public static ChildActivity s_childActivity;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        synchronized (MatchupsActivity.class) {
            s_childActivity = this;
        }
        setContentView(R.layout.child_activity);
    }

    public void changeUi() {
        code that changes UI
    }

    protected void onDestroy() {
        super.onDestroy();

        synchronized (MatchupsActivity.class) {
            s_childActivity = null;
        }
}
</code></pre>
