Check out example codes for "emboss button in android app". It will help you in understanding the concepts better.

Code Example 1

<?xml version="1.0" encoding="utf-8"?> 
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">

  <!-- Outside border/shadow -->
  <item>
    <shape android:shape="oval">
      <size android:width="200dp" android:height="200dp" />
      <gradient android:angle="90" android:startColor="#f4f4f4" android:endColor="#b9b9b9" />
    </shape>
  </item>

  <!-- Inset -->
  <item android:top="1dp" android:left="1dp" android:right="1dp" android:bottom="1dp">
      <shape android:shape="oval">
        <gradient android:angle="90" android:startColor="#dcdcdc" android:endColor="#c9c9c9" />
      </shape>
  </item>

  <!-- Inside border/shadow -->
  <item android:top="15dp" android:left="15dp" android:right="15dp" android:bottom="15dp">
    <shape android:shape="oval">
      <gradient android:angle="90" android:startColor="#8c8c8c" android:endColor="#cbcbcb" />
    </shape>
  </item>

  <!-- Main button -->
  <item android:top="16dp" android:left="16dp" android:right="16dp" android:bottom="16dp">
    <shape android:shape="oval">
      <solid android:color="#ffffff" />
    </shape>
  </item>

  <!-- Button image -->
  <item android:top="70dp" android:left="70dp" android:right="70dp" android:bottom="70dp">
    <shape android:shape="rectangle">
      <solid android:color="#3b88c2" />
      <corners android:radius="20dp" />
    </shape>
  </item>

  <item android:top="75dp" android:left="75dp" android:right="75dp" android:bottom="75dp">
    <shape android:shape="rectangle">
      <solid android:color="#ffffff" />
      <corners android:radius="20dp" />
    </shape>
  </item>

  <item android:top="80dp" android:left="80dp" android:right="80dp" android:bottom="80dp">
    <shape android:shape="rectangle">
      <solid android:color="#3b88c2" />
      <corners android:radius="20dp" />
    </shape>
  </item>

</layer-list>

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