launchModes, singleTask: how to switch between "screens"? Is Intents the only way, and if so I think I have a problem
<p>In a number of questions (<a href="http://stackoverflow.com/questions/2013865/header-views-and-buttons-how-do-i-attach-listeners-to-buttons-in-a-header-th">like this one</a>) I have been looking into how to "change screens" in my app. I have a "header" on top, with 4 buttons. Each button is meant to replace the "content" (ie change screen):</p>

<pre><code>+--------------------+
| menu with buttons  |
+--------------------+
|                    |
|                    |
|  C O N T E N T     |
|                    |
|                    |
+--------------------+
</code></pre>

<p>When I click a Menu button, I run the following code:</p>

<pre><code>@Override
public void onClick(View v)
{
    Intent myIntent = new Intent(BaseActivity.this, ActivityMain.class);
    BaseActivity.this.startActivity(myIntent);
}
</code></pre>

<p>As you can see, the <i>startActivity</i> is executed. Now, if I do not specify <i>"launchMode"</i> for the Activity that means that launchMode = normal. If launchMode == normal that means that the Activity will be re-created each and every time I navigate using the top header buttons, and that means that all data entered in "form elements" are gone (or at least hidden).</p>

<p>So, I found the launchMode "singleTask" that sounded sort of nice. If I add that launchMode to my Activity, it will not be re-created when I navigate with the buttons, thus keeping state. Great! Well, until I read <a href="http://developer.android.com/guide/topics/fundamentals.html#acttask" rel="nofollow">this</a>:</p>

<p><i>As noted above, there's never more than one instance of a "singleTask" or "singleInstance" activity, so that instance is expected to handle all new intents.</i></p>

<p>I found out that the sentence mean that <b>there can be only one</b> Activity that has the launchMode set to "singleTask" - if I have more than one it wont work (no compiler error though). </p>

<p><b>This means that I can only "keep the state" for one Activity, when switching back and forth (navigating) between my screens!</b></p>

<p><a href="http://stackoverflow.com/questions/2032173/configuration-changed-orientation-change-and-destroying-activities-is-this-th">Once again</a>, is this really how it supposed to work?</p>
