Created attachment 247060 [details] [review]
proposed patch

Thanks!  I like the symmetry that this gives to the API.

One quick question:  How do you envision using the text from the filename entry as entered by the user?  It could contain things like "~/Something/blah.txt" that you need to parse yourself.

indeed, I'd need to parse that myself.

one use case is: the dialog is opened in 'recent used' mode, so, there's no physical directory (get_filename() would return null).

then the user would save an image, he set the name 'image.png' and the realizes it can change the format to jpg, by clicking in a combobox custom widget. the callback function would get the filename and change only the extension part.

Nice use case.  I've pushed your patch with two changes:

- Make get_current_name() return a non-const gchar *, to be consistent with the rest of the file chooser.

- Minor tweaks to the docstring.

This is in master in commit 84b4910b39bdd.