android_frameworks_base/docs/html/design/patterns/multi-pane-layouts.jd

page.title=Multi-pane Layouts
@jd:body

<p>When writing an app for Android, keep in mind that Android devices come in many different screen
sizes and types. Make sure that your app consistently provides a balanced and aesthetically pleasing
layout by adjusting its content to varying screen sizes and orientations.</p>
<p><em>Panels</em> are a great way for your app to achieve this. They allow you to combine multiple views into
one compound view when a lot of horizontal screen real estate is available and by splitting them up
when less space is available.</p>
<h2 id="combining-views">Combining Multiple Views Into One</h2>

<p>On smaller devices your content is typically divided into a master grid or list view and a detail
view. Touching an item in the master view opens a different screen showing that item's detail
information.</p>

<img src="{@docRoot}design/media/multipane_views.png">

<p>Because tablets have more screen real estate than phones, you can use panels to combine the related
list and detail views into a single compound view. This uses the additional space more efficiently
and makes navigating the app easier. </p>

<img src="{@docRoot}design/media/multipane_view_tablet.png">

<p>In general, use the pane on the right to present more information about the item you selected in the
left pane. Make sure to keep the item in the left pane selected in order to establish the
relationship between the panels.</p>
<h2 id="orientation">Compound Views and Orientation Changes</h2>

<p>Screens should have the same functionality regardless of orientation. If you use a compound view in
one orientation, don't split it up when the user rotates the screen. There are several techniques
you can use to adjust the layout after orientation change while keeping functional parity intact.</p>

<div class="layout-content-row">
  <div class="layout-content-col span-8">

    <img src="{@docRoot}design/media/multipane_stretch.png">
    
  </div>
  <div class="layout-content-col span-5">

<h4>Stretch/compress</h4>
<p>Adjust the column width of your left pane to achieve a balanced layout in both orientations.</p>

  </div>
</div>

<div class="layout-content-row">
  <div class="layout-content-col span-8">

    <img src="{@docRoot}design/media/multipane_stack.png">
    
  </div>
  <div class="layout-content-col span-5">

<h4>Stack</h4>
<p>Rearrange the panels on your screen to match the orientation.</p>

  </div>
</div>

<div class="layout-content-row">
  <div class="layout-content-col span-8">

    <img src="{@docRoot}design/media/multipane_expand.png">
    
  </div>
  <div class="layout-content-col span-5">

<h4>Expand/collapse</h4>
<p>When the device rotates, collapse the left pane view to only show the most important information.
Provide an <em>expand</em> control that allows the user to bring the left pane content back to its original
width and vice versa.</p>

  </div>
</div>

<div class="layout-content-row">
  <div class="layout-content-col span-8">

    <img src="{@docRoot}design/media/multipane_show.png">
    
  </div>
  <div class="layout-content-col span-5">

<h4>Show/hide</h4>
<p>After rotating the device, show the right pane in fullscreen view. Use the Up icon in the action bar
to show the left panel and allow navigation to a different email. Hide the left panel by touching
the content in the detail panel.</p>

  </div>
</div>

<h2 id="checklist">Checklist</h2>

<ul>
<li>
<p>Plan in advance on how your app scales to different screen sizes and screen orientations.</p>
</li>
<li>
<p>Identify the most appropriate method for the panels in your compound views to reorganize
  themselves when screen orientation changes.</p>
</li>
<li>
<p>Look for opportunities to consolidate your views into multi-panel compound views.</p>
</li>
<li>
<p>Make sure that your screens provide functional parity after the screen orientation
  changes.</p>
</li>
</ul>