amm_sdk_sample/res/drawable/mm_title_btn_back.xml

<?xml version="1.0" encoding="UTF-8"?>
<selector
  xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_focused="true" android:drawable="@drawable/mm_title_back_focused" />
		<item android:state_pressed="true" android:drawable="@drawable/mm_title_back_pressed" />
		<item android:state_selected="true" android:drawable="@drawable/mm_title_back_pressed" />
		<item android:drawable="@drawable/mm_title_back_normal" />
</selector>