Make xdg-desktop-portal-kde part of Plasma release

[Jan Grulich]

Hi,

I would like to request/discuss inclusion of xdg-desktop-portal-kde [1] into 
Plasma to have it released with Plasma 5.10 and so on. 

What is xdg-desktop-portal-kde:
It's a KDE implementation of Flatpak portals backend [2], currently with 
support of AppChooser, FileChooser, Notification and Print portals. 

How it works:
An app running in sandbox communicates with outside world using 
org.freedesktop.portal.Foo interfaces (each of them is one portal). These 
interfaces are registered by xdg-desktop-portal (on DBus as 
org.freedesktop.portal.Desktop service). This requires support in library to 
make widgets etc. do calls to o.f.p.Foo interfaces instead of doing what they 
usually do. This is already implemented in KNotifications and for Qt part we 
have flatpak platform plugin. Then xdg-desktop-portal calls desktop specific 
implementations to present native dialogs and have proper integration. That's 
where xdg-desktop-portal-kde takes place. It exposes it's implementation on 
DBus as org.freedesktop.impl.portal.desktop.kde service. Then in case of KDE 
when user requests a file dialog from a sandboxed application, Qt platform 
plugin does a dbus call to xdg-desktop-portal instead of showing a dialog and 
xdg-desktop-portal forwards this to our backend implementation and we show a 
native dialog to the user, this time this dialog is not running in sandbox and 
user can open a file which is outside the sandboxed application. Same way it 
works with opening URLs, notifications etc.

What do you think? 

[1] - https://cgit.kde.org/xdg-desktop-portal-kde.git/
[2] - http://flatpak.org/xdg-desktop-portal/portal-docs.html#idm140258860052032

Regards,
Jan
-- 
Jan Grulich,
Software Engineer, Desktop Team
Red Hat