Since I am working with X10, I got the X10 language highlighting for gedit. This works, but whenever I open an .x10 file I first have to change the "Highlight Mode" to "X10", otherwise there is no highlighting at all. How do I make gedit auto-detect .x10 files?
If X10 files are not highlighted by default you can activate Snippets plugin. I assume you have set the .lang file under
/usr/share/gtksourceview-3.0/language-specs. From plugin you can activate x10 highlightniing by shortcuts or snippet name followed by Tab key. I am not sure what Drop target option is for, nevertheless there is no way make it auto-detect IMHO.
I know this is not what you've been looking for but it will ease the trouble :)