http://stackoverflow.com/questions/2711858/is-it-possible-to-set-font-for-entire-application

public final class FontsOverride {

    public static void setDefaultFont(Context context,
            String staticTypefaceFieldName, String fontAssetName) {
        final Typeface regular = Typeface.createFromAsset(context.getAssets(),
                fontAssetName);
        replaceFont(staticTypefaceFieldName, regular);
    }

    protected static void replaceFont(String staticTypefaceFieldName,
            final Typeface newTypeface) {
        try {
            final Field staticField = Typeface.class
                    .getDeclaredField(staticTypefaceFieldName);
            staticField.setAccessible(true);
            staticField.set(null, newTypeface);
        } catch (NoSuchFieldException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        }
    }
}

On splash screen call

FontsOverride.setDefaultFont(this, "DEFAULT", "MyFontAsset.ttf");
FontsOverride.setDefaultFont(this, "MONOSPACE", "MyFontAsset2.ttf");
And set in style.xml
 <style name="AppTheme" parent="AppBaseTheme">
        <item name="android:typeface">monospace</item>
    </style>


Thanks