Android Typeface Font Default / Fallback

Question

I draw (canvas) a text using a custom typeface (precisely: I use a custom font). However, this font doesn't support many characters and thus some (unsupported) characters are looking differently. Now I am asking myself the following questions:

• How does an unsupported character look like - does the look depend on a system setting / is the look the same on all devices?
• What (default) font is used for unsupported characters? (do the unsupported letters have the same dimensions as the supported ones in the end?)

Answer 1

I digged through the Android code and would like to post my findings:

A Typeface.class instance is created using the static create-methods of the Typeface.class (createFromAsset/createFromFile/create/etc.). The instance then holds a list of fonts (unmodifiable List<Font>). The first element of this list is the main font (specified) and the other elements (index: 1 - (size-1)) are default fonts which are retrieved from the FontLoader.class (getFallBackFonts())

Among others, the Paint.class / Canvas.class (drawText()) use a Typeface.class instance to draw the texts (to measure characters / to draw / etc.). They try to use the main font (Typeface.mFonts[0]) when possible. If a character cannot be found in the main font then they try to use a fallback font (Typeface.mFonts[1]-Typeface.mFonts[size-1]) to measure and draw the character.

Conclusion

You can use a Typeface.class instance if you want to use a custom font. If your custom font doesn't support certain characters that you want to draw (/that you use in your text) then the system tries to make use of fallback-fonts. These fallback fonts are loaded from the system by the FontLoader.class (from a system-xml).