title: Drop shadow on Action Bar and Custom Camera View
body: <p>Currently, I have the following application, which consists of a ActionBar and a Custom View. It looks like this</p>
  
  <p><img src="https://i.stack.imgur.com/BMzKv.jpg" alt="enter image description here"></p>
  
  <p>I try to achieve drop shadow effect on</p>
  
  <ol>
  <li>Action bar (Use library from <a href="http://actionbarsherlock.com/" rel="nofollow noreferrer">ActionBarSherlock</a>)</li>
  <li>Custom camera view</li>
  </ol>
  
  <p>By using "9 patch" technique, I am able to drop shadow on the action bar, but not the custom view.</p>
  
  <p>Here is the technique I am using. I specific <code>windowContentOverlay</code> to a "9 patch" image. According to documentation, here is what <code>windowContentOverlay</code> used for.</p>
  
  <blockquote>
    <p>This Drawable is overlaid over the foreground of the Window's content
    area, usually to place a shadow below the title.</p>
  </blockquote>
  
  <p>I expect both action bar and custom view are categorized as <code>Drawable</code>. By having the following style across entire activity</p>
  
  <p><strong>values/styles.xml</strong></p>
  
  <pre><code>&lt;resources&gt;
      &lt;style name="AppTheme" parent="@style/Theme.Sherlock.Light"&gt;
          &lt;item name="android:windowContentOverlay"&gt;@drawable/actionbar_shadow&lt;/item&gt;
      &lt;/style&gt;
  &lt;/resources&gt;
  </code></pre>
  
  <p><strong>AndroidManifest.xml</strong></p>
  
  <pre><code>&lt;application android:theme="@styles/AppTheme"&gt;
  </code></pre>
  
  <p><strong>actionbar_shadow.9.png</strong></p>
  
  <p><img src="https://i.stack.imgur.com/xoEap.png" alt="enter image description here"></p>
  
  <p>However, I can only see shadow on action bar, but not my custom camera view.</p>
  
  <p>For information, here is how I layout my only Activity.</p>
  
  <p><strong>layout/main.xml</strong></p>
  
  <pre><code>&lt;LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
      android:layout_width="fill_parent"
      android:layout_height="fill_parent"
      android:orientation="vertical"
      android:gravity="center" &gt;
  
      &lt;view xmlns:android="http://schemas.android.com/apk/res/android"
          class="org.yccheok.gui.CustomView"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
      /&gt;
  
  &lt;/LinearLayout&gt;
  </code></pre>
  
  <p>I was wondering, why <code>windowContentOverlay</code> technique is workable for action bar, but not my custom camera view?</p>