title: Android button background shape: circle is squished
body: <p>fragment_camera.xml:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
      android:layout_width="match_parent" android:layout_height="match_parent"&gt;
  
      &lt;ImageView
          android:id="@+id/iv_camera"
          android:layout_width="match_parent"
          android:layout_height="match_parent"
          android:layout_alignParentTop="true" &gt;
      &lt;/ImageView&gt;
  
      &lt;Button
          android:id="@+id/btn_take_pic"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:layout_alignParentBottom="true"
          android:layout_centerHorizontal="true"
          android:layout_marginBottom="20dp"
          android:background="@drawable/circle" &gt;
      &lt;/Button&gt;
  
  &lt;/RelativeLayout&gt;
  </code></pre>
  
  <p>circle.xml:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;shape
      xmlns:android="http://schemas.android.com/apk/res/android"
      android:shape="oval"&gt;
  
      &lt;solid
          android:color="#87cefa"/&gt;
  
      &lt;size
          android:width="40dp"
          android:height="40dp"/&gt;
  &lt;/shape&gt;
  </code></pre>
  
  <p>Result:</p>
  
  <p><img src="https://i.stack.imgur.com/fEXQR.png" alt="enter image description here"></p>
  
  <p>My circle is squished *cry*. </p>
  
  <p>As the button does not contain any content I'm guessing the button has a default width and height. How can I get the button to adjust itself to the drawable? Must I set the width and height the same dimensions as the drawable, or is there a dynamic way of doing this?</p>