title: Why doesn't `android:foreground` attribute work?
body: <p>Take a look at this small android app:</p>
  
  <p>MainActivity.java:</p>
  
  <pre><code>package io.github.gsaga.toucheventtest;
  
  import android.support.v7.app.AppCompatActivity;
  import android.os.Bundle;
  
  public class MainActivity extends AppCompatActivity {
  
      @Override
      protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_main);
      }
  }
  </code></pre>
  
  <p>activity_main:
      </p>
  
  <pre><code>&lt;ImageView android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:foreground="@drawable/ic_launcher_background"
      xmlns:android="http://schemas.android.com/apk/res/android" /&gt;
  </code></pre>
  
  <p>The image pointed to by <code>android:foreground</code> isn't displayed, but it appears if I change <code>foreground</code> to <code>src</code> or <code>background</code> in <code>activity_main.xml</code>. This code seems to follow the instructions described here:</p>
  
  <p><a href="https://developer.android.com/reference/android/view/View.html#attr_android:foreground" rel="noreferrer">https://developer.android.com/reference/android/view/View.html#attr_android:foreground</a></p>
  
  <p>Why doesn't the <code>android:foreground</code> tag work in above code?</p>
  
  <p><strong>NOTE:</strong></p>
  
  <p><code>minSdkVersion</code> is <code>19</code>, I'm running this app on <code>Android 5.1</code> (<code>API level 22</code>)</p>