gboolean set_as_default_for_extension ( GAppInfo* appinfo, const char* extension, GError** error )
A string containing the file extension (without the dot).
The data is owned by the caller of the method. The value is a file system path, using the OS encoding.
The return location for a recoverable error.
The argument can be
If the return location is not
NULL, then you must initialize it to a
The argument will be left initialized to
NULLby the virtual function if there are no errors.
In case of error, the argument will be set to a newly allocated
GError; the caller will take ownership of the data, and be responsible for freeing it.