API for adding application-specific fonts

[rkern]

There is a need for an application to provide one or more fonts that are to be used in the application, particularly for Chaco labels. For example, supporting CJK languages across platforms can benefit by providing a single suitably-licensed font and specifying that the appropriate preferred_fonts category uses it.

One can currently hack through the implementation details of kiva.fonttools.font_manager to accomplish this, but there is a need for a blessed, documented API to accomplish this.

[corranwebster]

This will probably require more than just modifying the kiva.fonttools code, as a most of the Kiva backends just take the name of the font and then use their own internal font discovery mechanisms to resolve it (eg. QPainter backend will use Qt font discovery).

[jwiggins]

It might be worth checking if QFontDatabase.addApplicationFont can help here.

[jwiggins]

@rahulporuri We should consider adding this to 5.1.0

[jwiggins]

QFontDatabase.addApplicationFont works as expected with the QPainter kiva backend. As was already pointed out, there will need to be matching changes in the kiva.fonttools code in order to work with other backends.

[jwiggins]

wx.Font.AddPrivateFont exists as well. It has some weird caveats, but since Wx support is supplied on a best effort basis...