title: Deep linking and up navigation in Android
body: <p>I have couple of questions regarding deep linking in conjunction with up navigation. </p>
  
  <p>In my application there is following hierarchy of activities:</p>
  
  <pre><code>HomeActivity  -&gt;  ItemListActivity  -&gt;  ItemDetailActivity
  </code></pre>
  
  <p>With deep linking (user clicks on a url from browser, email client etc) user may directly go to the <code>ItemDetailActivity</code>.</p>
  
  <p>In normal flow as shown above the back and up navigation will be exactly the same. </p>
  
  <p>But if <code>ItemDetailActivity</code> is opened via deep linking what should be the up navigation flow? Should it just behave like back and go to the starting activity or it should go to the <code>HomeActivity</code>? As far as I know up navigation should remain in the app and it can not go to <code>ItemListActivity</code> as search criteria to show item list is not known hence to <code>HomeScreen</code>. </p>
  
  <p>Also I want the <code>launchMode</code> of <code>ItemDetailActivity</code> to be <code>singleTask</code>. </p>