Firefox(orange) button > Tools > Options > Application

• Search for "PDF" > Action "Alway Ask"

This changes the application that is automatically applied, not the default application.

You can set the default application in Nautilus by right-clicking a pdf file and open the Properties and go to the Open with tab.

• Nautilus: right-click file > Properties > Open with

See also:

• http://blog.radevic.com/2012/02/how-to-set-default-apps-aka-how-to-use.html
• man xdg-mime
• xdg-mime query default application/pdf
• xdg-mime default okularApplication_pdf.desktop application/pdf

• /usr/share/applications/mimeinfo.cache and defaults.list
• ~/.local/share/applications/mimeapps.list

If you choose an application via "Use other" and browse to okular (/usr/bin/okular) and set that as the default then it should stay in that list as a choice if you select another application.

This is real progress, a solution to the problem as posted. The command: xdg-mime default okularApplication_pdf.desktop application/pdf makes okular the default.

However when I added okular to the choices for applications in:

• Edit>Preferences>Applications>PDF

the popup box that appears when I click Download on the preview page changed. The pulldown menu that appears next to "Open with" used to have 3 entries:

1. Document Viewer (default)
2. Acroread
3. Other

Now it has only 2:

1. Okular (Default)
2. Other

I'd like it to read

1. Okular (Default)
2. Acroread
3. Other

How can I control the entries in this pulldown list?

Also, how can I make the default choice in the popup box be

• Open With <whatever> , rather than
• Save File ?

You can (temporarily) set the default to Acroread like I wrote above by using "Use other" and browse to the Acroread program. That should add Acroread to the list of choices when you change the setting to one of the other available choices.

If only...

Maybe I don't understand. Here's what I did:

• Prime Firefox to show acroread in the pull-down menu:

1. Open foo.pdf in the Firefox previewer
2. Click the download icon in the previewer; a pop-up window appears.
3. Open the pull-down menu in the pop-up window
4. Choose "Other..."; a file chooser window appears
5. Choose /usr/bin/acroread in the pull-down window
6. Select "Open With" in the pop-up window
7. Click OK

• Test the result:

1. Open foo.pdf in the Firefox previewer
2. Click the download icon in the previewer; a pop-up window appears.
3. Open the pull-down menu in the pop-up window
4. I would expect to see "Acroread" in the pull-down window; no such luck.

Thanks much for your assistance.

Try to make this change in the PDF setting in Edit > Preferences > Applications

Today I started Firefox and found that things are working as desired. (Because of the restart?) Thanks for your help.