I just tried on manjaro linux.
Effectively FF will use native KDE dialogs, BUT it does not pre-fill the file name where to save.. then it lost the name given by the website.
Is it because I miss a setting or something else?

As like that I prefer the GTK dialog even it's not integrated in my DE, or to use the suse patched FF.

In T10189#170238, @scachemaille wrote:

I just tried on manjaro linux.
Effectively FF will use native KDE dialogs, BUT it does not pre-fill the file name where to save.. then it lost the name given by the website.
Is it because I miss a setting or something else?

Already fixed: https://bugs.kde.org/show_bug.cgi?id=402077

Thanks for this info Nate, FireFox 64 looks a lot better and more useful on Plasma :)

We cannot modify the firefox desktop file.

Suggestion for how/where to apply the setting otherwise?

Maybe /etc/environment or other files as described here: https://help.ubuntu.com/community/EnvironmentVariables#System-wide_environment_variables

Or ~/.profile? But either one will affect all apps, not just Firefox. I can't guarantee that there won't be any regressions in this case. :/

Maybe we could ship a modified .desktop file but install it to ~/.local/share/applications? That way it would take precedence over the system one, but the system one would be untouched. This is what happens if you use KMenuEdit to edit the desktop file yourself, in fact.

In /etc/profile.d we can create new file firefox-kde-dialogs.sh that will apply GTK_USE_PORTAL=1 for all users.

In T10189#171209, @ngraham wrote:

Or ~/.profile? But either one will affect all apps, not just Firefox. I can't guarantee that there won't be any regressions in this case. :/

Maybe we could ship a modified .desktop file but install it to ~/.local/share/applications? That way it would take precedence over the system one, but the system one would be untouched. This is what happens if you use KMenuEdit to edit the desktop file yourself, in fact.

I think the problem with local desktop files is that if you remove Firefox or it has an updated desktop file the local one is still showing up.
Is there really no way to make a modified system-wide desktop entry?

I think the problem with local desktop files is that if you remove Firefox or it has an updated desktop file the local one is still showing up.
Is there really no way to make a modified system-wide desktop entry?

Yes, you could try to persuade Ubuntu to package Firefox with this option already there in the .desktop file, if it would have no adverse impact while running other DEs.

Many other options would have problems like those already identified such as: being overwritten by Firefox upgrades, overriding the default .desktop entry which could cause important changes in the default to not be used, being persistent even if a user decides to remove or modify Firefox on their system, may still apply if the user decides to install or log in to another DE on a kubuntu system.

What I usually use to tweak my systems:

a) Patch /usr/bin/startkde and put the env var there. Simple and only set for a plasma session

b) Instead of modifying the desktop file, one could create a wrapper script called firefox

 and put it to e.g. /usr/share/firefox-kde/   Then put this dir to PATH during plasma
startup

Does not work on systems with a local firefox wrapper (like my systems ;-) )

c) generate a script that is source'ed during plasma startup ( one of ~/.config/autostart*/ ?) and set the env var or PATH for b) above)

d) can we use the alternative system to make /usr/bin/firefox a link a firefox.kde wrapper script?
(check if we're inside a plasma session, then set env var)

e) dpkg-divert?

Oh, maybe: prevent problems(?) with sh -> dash systems use the env tool:

Exec=env GTK_USE_PORTAL=1 /usr/lib/...

Set it via a script in /etc/xdg/plasma-workspace/env/ ?

Using export GTK_USE_PORTAL=1

In T10189#171232, @clivej wrote:

Set it via a script in /etc/xdg/plasma-workspace/env/ ?

Using export GTK_USE_PORTAL=1

As in https://dev.getsol.us/R4535:a6093baf617dbaa7344de4ac1a8d48137f3e8c7f

Ignoring non relevant things in that change!

In our case adding a 50-firefox.sh (arbitrary name) containing export GTK_USE_PORTAL=1 to /usr/share/kubuntu-default-settings/kf5-settings/plasma-workspace/env/ seems to work.

Might have to patch xdg-desktop-portal-kde too with:

https://cgit.kde.org/xdg-desktop-portal-kde.git/commit/?id=ccea985840cf5b05b0359067854abc3da080e737

In T10189#171262, @clivej wrote:

Might have to patch xdg-desktop-portal-kde too with:

https://cgit.kde.org/xdg-desktop-portal-kde.git/commit/?id=ccea985840cf5b05b0359067854abc3da080e737

Just did!

https://launchpad.net/ubuntu/+source/xdg-desktop-portal-kde/5.14.4-0ubuntu2

In T10189#171260, @rikmills wrote:

In our case adding a 50-firefox.sh (arbitrary name) containing export GTK_USE_PORTAL=1 to /usr/share/kubuntu-default-settings/kf5-settings/plasma-workspace/env/ seems to work.

Test build of kubuntu-settings adding this change here:

https://launchpad.net/~kubuntu-ppa/+archive/ubuntu/staging-misc/+sourcepub/9804332/+listing-archive-extra

Please test.

Note: reminder that you need both xdg-desktop-portal and xdg-desktop-portal-kde packages installed, and restart your session.

Before: Cross-platform FF Dialogues on Kubuntu Daily Build (DD, fully updated).

$ sudo add-apt-repository ppa:kubuntu-ppa/staging-misc
$ sudo apt update && sudo apt full-upgrade -y && sudo apt autoremove -y

Restarting FF had no effect. Re-booting, and the Save Page As... and Open File... Dialogues did not appear at all. Possibly because:

$ apt-cache policy xdg-desktop-portal
xdg-desktop-portal:
  Installed: (none)
  Candidate: 1.0.3-1
  Version table:
     1.0.3-1 500
        500 http://us.archive.ubuntu.com/ubuntu disco/main amd64 Packages

So I installed it (should have done this first)

$ sudo apt install -y xdg-desktop-portal

Rebooted again.

And the lovely KDE versions of Save Page As... and Open File... Dialogues are there.
Note: I used to call that panel kdialog, though kdialog does not appear on the window title bar.

In T10189#171295, @mparillo wrote:

So I installed it (should have done this first)

$ sudo apt install -y xdg-desktop-portal

Yeah, should we adopt or keep this change I'll add that to the desktop seed and/or settings package recommends, so that users will have it installed by default. I just hadn't bothered in the test package builds.

Ok. Maybe wider testing in Disco 19.04.

https://launchpad.net/ubuntu/+source/kubuntu-settings/1:19.04ubuntu2

kubuntu-settings (1:19.04ubuntu2) disco; urgency=medium

• Make plasma session set env var 'GTK_USE_PORTAL=1' to enable Firefox native KDE file-picker dialog. Experimental change for wider testing.
• Recommend the required xdg-desktop-portal & xdg-desktop-portal-kde.

Setting this even Plasma session wide crashes Thunderbird, which is NOT acceptable.

Changes reverted: https://launchpad.net/ubuntu/+source/kubuntu-settings/1:19.04ubuntu3

Solutions to this welcomed.

Looks like this will be fixed with Thunderbird 68, which supports GTK_USE_PORTAL=1: https://bugzilla.mozilla.org/show_bug.cgi?id=1471420.

i.e. not before July 2019?

I guess. :/

Is there really no sane way for us to set the environment variable only for Firefox?

I have problem that KDE file save dialog in Firefox don't remember last used folder, so I fill issue: https://bugs.kde.org/show_bug.cgi?id=403199 - does it reproduced in your environment?

Here https://bugzilla.mozilla.org/show_bug.cgi?id=1514605 is Thunderbird bug report about crash, can we add backtrace report for increase solving the bug?

FWIW this is being considered for Neon in D18726: hijack firefox and force portals upon it.

Maybe we could do something similar?

I would love to see this as default in Kubuntu! I would like to migrate my fathers PC from Windows 7 to Kubuntu in 2020 and the GTK-file-picker in firefox is one the main usability problems for him, because he does a lot of image uploading in firefox.

Thunderbird fix crashes with GTK_USE_PORTAL=1 here https://hg.mozilla.org/releases/comm-esr68/rev/d741c4f6b95c5f3e063738d171b2fccea3695263 so now we can make this variable globally.