On Sun, 10 Nov 2019 21:18:46 +0100, "R.Wieser" 
declaimed the following:


>
>No.  Currently I'm getting a bit tired of this guessing game, and instead
>want to find/have information.  Sorry.
>

 Unfortunately, that is going to require a LOT of Google (and man page)
searches, trying various keywords.

 For example, finding out how update-mime-database works led me to

https://www.linuxtopia.org/online_books/linux_desktop_guides/gnome_2.14_admin_g
uide/mimetypes-database.html

This was in the midst of playing with the sequence of operations shown
next, when I encountered a file that said DO NOT EDIT and that was
generated by the update command.:

-=-=-=-

Open With >
 Geany
 Thonny Python IDE
 Text Editor
 gVim
 Vim
 LibreOffice Writer

pi@rpi3bplus-1:~$ sudo vim /usr/share/applications/mousepad.desktop
Change
 GenericName=Text Editor
To
 GenericName=MousePad
{Also changed the [en_AU] and [en_GB] lines}

No immediate change on menu

pi@rpi3bplus-1:~$ sudo vim /usr/share/applications/gvim.desktop
Added gVim to genericname (no effect)
Added
 ;Development
to Categories

gVim now shows up on Programming menu (beside on Accesories)

 {here's where the update-mime-database search led me}
pi@rpi3bplus-1:~$ sudo vim /usr/share/mime/packages/freedesktop.org.xml
Commented out  
   -->
for the text/x-python section; but left text/x-python3 as sub-class of
text/x-python

pi@rpi3bplus-1:~$ sudo update-mime-database /usr/share/mime


Open With >
 Geany
 Thonny Python IDE

 Removing the text/plain subclass removed all the generic text editors

pi@rpi3bplus-1:~$ sudo vim /usr/share/applications/gvim.desktop
Added
 text/x-python;
to end of MimeTypes list

No change to right click menu; REBOOT
Still no change on menu; getting specific entries back is the next step


Open with >
 Open with...
  Selected gVim and [X]Set selected ... default



Do same.


Open With >
 gVim
 Geany
 Thonny Python IDE

Redid (on both .py file) Open with.../selected Thonny and [X]Set selected
...


Open With >
 Thonny Python IDE
 gVim
 Geany

Reboot to see if setting stays

It did (at least once)...
-=-=-=-

 So... It looks like I was able to "resort" the Open With > menu. It
required using the Open with... sub-menu, [X] the Set selected flag, and
select the one you want last (it will become the top). Repeat with each
candidate so the previous selections get pushed down.

 You have to do this for each different MIME type the files are
identified as (eg; python vs python3).

NOTE: I'm still running the default file manager for Raspbian, which I
believe is Thunar. Don't know if the one you are running will behave the
same way.


--
 Wulfraed                 Dennis Lee Bieber         AF6VN
 wlfraed@ix.netcom.com    http://wlfraed.microdiversity.freeddns.org/

--- SoupGate-Win32 v1.05