stack activity in android
<p>Hi i am working with android , and i have a problem with the activity stack. As i know, when someone uses the back button, reload the back activity. But in the case i have many layouts shown from one activity, how can i go back to them.</p>

<p>Here is the deal, i am using a listview filled with categories, and when i press an item, i reuse the activity and the layout, to show its subcategories. So what i need is to came back no to the back activity, not to the back layout, but to the back "state".</p>

<p>Well, the idea is simple, first i show all the categories with no parent, then when i pressed an item, i show its subcategories.</p>
