FontMask:
Family: the font family is specified.
Style: the font style is specified.
Variant: the font variant is specified.
Weight: the font weight is specified.
Stretch: the font stretch is specified.
Size: the font size is specified.
Gravity: the font gravity is specified (Since: 1.16.)
*
The bits in a #PangoFontMask correspond to fields in a
#PangoFontDescription that have been set.
FontMask: Family: the font family is specified. Style: the font style is specified. Variant: the font variant is specified. Weight: the font weight is specified. Stretch: the font stretch is specified. Size: the font size is specified. Gravity: the font gravity is specified (Since: 1.16.) * The bits in a #PangoFontMask correspond to fields in a #PangoFontDescription that have been set.