Themes and Styles
are defined in the themes.xml and styles.xml files of the sdk implementation in your environment (different for different versions of Android or sdk).
find your computer for themes.xml (for example, you will probably find several instances of it in the "program files / android" folder on a 32-bit Windows machine).
this post explains how to configure these attributes.
you can also set explicit size attributes to your xml layout file by changing the TextView attributes:
<TextView android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="15sp is the 'normal' size." android:textSize="15sp" />
this post explains how to customize android fonts (including fontType, fontColor, shadow, bold, italic) directly in the xml layout file.
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