Android: How to use Android default font size example

Small:

<style name="DefaultMedium">

<item name="android:textAppearance">?android:attr/textAppearanceSmall</item>

</style>

Medium:

<style name="DefaultMedium">

<item name="android:textAppearance">?android:attr/textAppearanceMedium</item>

</style>

Large:

<style name="DefaultMedium">

<item name="android:textAppearance">?android:attr/textAppearanceLarge</item>

</style>

Reference: Android source code

Android Styles.xml
https://github.com/android/platform_frameworks_base/blob/master/core/res/res/values/styles.xml

Android Res files
https://github.com/android/platform_frameworks_base/tree/master/core/res/res