title: why `ifroom` does not work - android studio
body: <p>hi there I try set <code>ifroom</code> in my menu item. you can see in this code I try all possible senario (please see each <code>showAsAction</code> item</p>
  
  <pre><code>&lt;menu xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:app="http://schemas.android.com/apk/res-auto"
      xmlns:tools="http://schemas.android.com/tools" tools:context=".MainActivity"&gt;
  
      &lt;item
          android:id="@+id/action_forward"
  
          android:title="forward"
          android:icon="@drawable/ic_action_arrow_forward"
          android:showAsAction="ifRoom"
          &gt;&lt;/item&gt;
  
  
      &lt;item
          android:id="@+id/action_zoom_in"
          android:title="zoom in"
          android:icon="@drawable/ic_action_zoom_in"
          android:showAsAction="ifRoom|withText"
          &gt;&lt;/item&gt;
  
  
  
      &lt;item
          android:id="@+id/action_home"
          android:title="home"
          android:icon="@drawable/ic_action_home"
          app:showAsAction="ifRoom|withText"
          &gt;&lt;/item&gt;
  
  
      &lt;item
          android:id="@+id/action_refresh"
          android:title="refresh"
          android:icon="@drawable/ic_action_refresh"
          app:showAsAction="ifRoom"
          &gt;&lt;/item&gt;
  
      &lt;item
          android:id="@+id/action_zoom_out"
          android:title="zoom out"
          android:icon="@drawable/ic_action_zoom_out"
          showAsAction="ifRoom"
          &gt;&lt;/item&gt;
  
      &lt;item
          android:id="@+id/action_back"
          android:title="back"
          android:icon="@drawable/ic_action_arrow_back"
          app:showAsAction="always"
          &gt;&lt;/item&gt;
  &lt;/menu&gt;
  </code></pre>
  
  <p>but it just show <code>action_back</code> and <code>action_home</code> in main page.</p>
  
  <p>I am noob in android studio but I think this error related to width of menu.
  (It is not 100% width)</p>
  
  <p>Please see my <strong>main_activity.xml</strong></p>
  
  <pre><code>&lt;LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:tools="http://schemas.android.com/tools"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:orientation="vertical"
      tools:context=".MainActivity"&gt;
  
  
      &lt;include
          android:id="@+id/tool_bar_bottom"
          layout="@layout/tool_bar_bottom"
          android:layout_height="wrap_content"
          android:layout_width="match_parent"
          android:layout_gravity="center" /&gt;
  
  &lt;/LinearLayout&gt;
  </code></pre>
  
  <p>and 
  <strong>tool_bar_bottom.xml</strong></p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;android.support.v7.widget.Toolbar
      android:layout_height="wrap_content"
      android:layout_width="match_parent"
      android:background="@color/ColorPrimary"
      android:elevation="2dp"
      android:theme="@style/Base.ThemeOverlay.AppCompat.Dark"
      xmlns:android="http://schemas.android.com/apk/res/android" /&gt;
  </code></pre>
  
  <p>I think the structure is true and values of all <code>layout_width</code> is <code>match_parent</code> so why <code>ifroom</code> do not work for me?</p>