styles multiple inheritance

Styles do not support multiple inheritance (at least not as of Android 3.2).

The official docs say:

If you use the dot notation to extend a style, and you also includethe parent attribute, then the parent styles override any stylesinheritted through the dot notation.

You can only inherit one style. However, you can also make the inherited style inherit from another style, and so on:

<style name="WidgetTextBase">    <item name="android:typeface">serif</item>    <item name="android:textSize">12dip</item>    <item name="android:gravity">center</item></style><style name="WidgetTextHeader" parent="WidgetTextBase">    <item name="android:textStyle">bold</item></style><style name="BOSText" parent="WidgetTextHeader">    <item name="android:textColor">#051C43</item></style>

You can't inherit more than one style, but you can set up an inheritance chain.

For those who was looking for solution to just merge multiple different styles into one, you can use

public void applyStyle (int resId, boolean force)

https://developer.android.com/reference/android/content/res/Resources.Theme#applyStyle(int,%20boolean). And apply it that way

context.theme.applyStyle(R.style.MyAdditionalStyle, false)

Whenever you specify true as second argument, it overrides existing values in your theme, and when false it adds only non-overlapping values from R.style.MyAdditionalStyle

I haven't tested scenario with multiple styles yet, but according to docs you can achieve it. So that's how this approach can be used as an alternative to multiple inheritance.