Typeface.CustomFallbackBuilder

public static final class Typeface.CustomFallbackBuilder
extends Object

java.lang.Object
   ↳ android.graphics.Typeface.CustomFallbackBuilder

A builder class for creating new Typeface instance. There are two font fallback mechanisms, custom font fallback and system font fallback. The custom font fallback is a simple ordered list. The text renderer tries to see if it can render a character with the first font and if that font does not support the character, try next one and so on. It will keep trying until end of the custom fallback chain. The maximum length of the custom fallback chain is 64. The system font fallback is a system pre-defined fallback chain. The system fallback is processed only when no matching font is found in the custom font fallback.

Examples, 1) Create Typeface from single ttf file. 

 
 Font font = new Font.Builder("your_font_file.ttf").build();
 FontFamily family = new FontFamily.Builder(font).build();
 Typeface typeface = new Typeface.CustomFallbackBuilder(family).build();
2) Create Typeface from multiple font files and select bold style by default. 
 
 Font regularFont = new Font.Builder("regular.ttf").build();
 Font boldFont = new Font.Builder("bold.ttf").build();
 FontFamily family = new FontFamily.Builder(regularFont)
     .addFont(boldFont).build();
 Typeface typeface = new Typeface.CustomFallbackBuilder(family)
     .setWeight(Font.FONT_WEIGHT_BOLD)  // Set bold style as the default style.
                                        // If the font family doesn't have bold style font,
                                        // system will select the closest font.
     .build();
3) Create Typeface from single ttf file and if that font does not have glyph for the characters, use "serif" font family instead. 
 
 Font font = new Font.Builder("your_font_file.ttf").build();
 FontFamily family = new FontFamily.Builder(font).build();
 Typeface typeface = new Typeface.CustomFallbackBuilder(family)
     .setSystemFallback("serif")  // Set serif font family as the fallback.
     .build();
4) Create Typeface from single ttf file and set another ttf file for the fallback. 
 
 Font font = new Font.Builder("English.ttf").build();
 FontFamily family = new FontFamily.Builder(font).build();

 Font fallbackFont = new Font.Builder("Arabic.ttf").build();
 FontFamily fallbackFamily = new FontFamily.Builder(fallbackFont).build();
 Typeface typeface = new Typeface.CustomFallbackBuilder(family)
     .addCustomFallback(fallbackFamily)  // Specify fallback family.
     .setSystemFallback("serif")  // Set serif font family as the fallback.
     .build();

Summary

Public constructors

CustomFallbackBuilder(FontFamily family)

Constructs a builder with a font family.

Public methods

Typeface.CustomFallbackBuilder addCustomFallback(FontFamily family)

Append a font family to the end of the custom font fallback.

Typeface build(