Feature idea: preview

[feth]

Just a thought, do what you want, including deleting the present issue :)

Depending on the file type, a preview could be generated.
Simplest preview: a screenshot of the app.
More complex, depending on filetype: thumbnail the bitmap/html if it is relevant and highlight differences with previous save. If it's text, preview can be a diff.

[nojhan]

Yes, I was planning to do that.
Commit e0dfdbc adds a generic command operator that may be used for that.

But to have a portable and simple way, I don't see another way to do previews than having predefined software managers.
If we have a portable way to check for MIME=>apps (do we?), we need to pre-program the preview code, that depends on each targeted software.

[nojhan]

Python does not have a portable way to find the application associated with a MIME type, it has been discussed and tried, but seems to be abandoned now: https://bugs.python.org/issue3177

[nojhan]

I just made an example of a preview generation for inkscape, see fac6c7e