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

[Jan Grulich]

If you wonder how to properly test portals support you can use my testing 
application [1]. It has usage for everything, now including also test for 
printing portal.

[1] - https://github.com/grulja/flatpak-portal-test-kde.

On středa 19. dubna 2017 14:08:52 CEST Jan Grulich wrote:
> 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