fonts - Valid values for android:fontFamily and what they map to?

In the answer to this question the user lists values for android:fontFamily and 12 variants (see below). Where do these values come from? The documentation for android:fontFamily does not list this information in any place (I checked here, and here). The strings are listed in the Android styles.xml file in various places, but how do these map back to the Roboto font?

From android 4.1 / 4.2, the following Roboto font families are
available:

android:fontFamily="sans-serif"           // roboto regular  
android:fontFamily="sans-serif-light"     // roboto light  
android:fontFamily="sans-serif-condensed" // roboto condensed  
android:fontFamily="sans-serif-thin"      // roboto thin (android 4.2)  
android:fontFamily="sans-serif-medium"    // roboto medium (android 5.0)

in combination with this

android:textStyle="normal|bold|italic" 

12 variants are possible:

• Regular


• Italic


• Bold


• Bold-italic


• Light


• Light-italic


• Thin


• Thin-italic


• Condensed regular


• Condensed italic


• Condensed bold


• Condensed bold-italic

In the styles.xml file in the application I'm working on somebody listed this as the font family, and I'm pretty sure it's wrong:

Roboto-Regular.ttf

I'd like to get the theme for our app set up correctly (which includes using fontFamily correctly) and remove all the redundancy that is in some of the styles that were created before I had a look at the file.

Answer

Where do these values come from? The documentation for android:fontFamily does not list this information in any place

These are indeed not listed in the documentation. But they are mentioned here under the section 'Font families'. The document lists every new public API for Android Jelly Bean 4.1.

In the styles.xml file in the application I'm working on somebody listed this as the font family, and I'm pretty sure it's wrong:

Yes, that's wrong. You don't reference the font file, you have to use the font name mentioned in the linked document above. In this case it should have been this:

sans-serif

Like the linked answer already stated, 12 variants are possible:

Added in Android Jelly Bean (4.1) - API 16 :

Regular (default):

sans-serif
normal 

Italic:

sans-serif
italic

Bold:

sans-serif
bold

Bold-italic:

sans-serif
bold|italic

Light:

sans-serif-light
normal

Light-italic:

sans-serif-light
italic

Thin :

sans-serif-thin
normal

Thin-italic :

sans-serif-thin
italic

Condensed regular:

sans-serif-condensed
normal

Condensed italic:

sans-serif-condensed
italic

Condensed bold:

sans-serif-condensed
bold

Condensed bold-italic:

sans-serif-condensed
bold|italic

Added in Android Lollipop (v5.0) - API 21 :

Medium:

sans-serif-medium
normal

Medium-italic:

sans-serif-medium
italic

Black:

sans-serif-black
italic

For quick reference, this is how they all look like: