Can you explain why this need is not sufficiently covered by the font section in gnome-tweak-tool ? Nothing wrong with rolling your own in general, but this seems to be just useless duplication. Unless I am missing some extra twist, in which case I would propose to simply add that extra twist to gnome-tweak-tool instead of starting yet another tweak tool. --mclasen 18:09, 18 October 2011 (UTC)
Actually the sans/serif fonts for desktop/applications are a synthesized font, which consists of many fonts to cover many languages.
In the case of Chinese users, the default system Chinese font is "WenQuanYi Zen Hei"; but some users prefer to use "WenQuanYi Micro Hei".
Here are two ways to customize the font;
1. Change the desktop/application font to "WenQuanYi Micro Hei" in the gnome-tweak-tool;
2. Prepend the "WenQuanYi Micro Hei" to the font list of sans/serif font alias;
The two ways both works, but in the first method, the users may not be able to view Japanese/Korean texts.
For the second method, the user can customize the font lists of sans/serif font alias, to specify the prefered fonts for CJK languages in fonts-tweak-tool. --Peng Wu 06:26, Nov 25 2011 (UTC)
I think gnome-tweak-tool is just configuring Gnome/gtk's default fonts for Sans/Serif/Mono. Whereas this feature is about being able to configure fontconfig fallback fonts by lang. Petersen 05:37, 29 November 2011 (UTC)