Use Gtk.Application.inhibit instead of manually using login interface about haguichi

[ztefn]

Unfortunately, the functionalty that Gtk.Application.inhibit provides is different from what Haguichi needs. Haguichi does not start any operation that should not be interrupted. It merely listens for a PrepareForSleep() signal and then says "Hold on, let me quickly disconnect the Hamachi client before going to sleep..." in order to close the connection cleanly. And later on, when waking up, the connection is restored again. See the code at: https://github.com/ztefn/haguichi/blob/master/src/inhibitor.vala

Still, I'd love to hear if you know any other Gtk api that does provide this functionality.

[danirabbit]

Thanks for clarifying that! I don't know about that off the top of my head, but I'll ask around :)

[danirabbit]

It looks like LibPortal might be the route to go here. It seems like it has methods here to watch the session state: https://github.com/flatpak/libportal/blob/master/libportal/inhibit.c#L655

Or you could manually use the inhibit portal over dbus as described here: https://docs.flatpak.org/en/latest/portal-api-reference.html#gdbus-org.freedesktop.portal.Inhibit

And that should let you drop the login dbus interface

[ztefn]

Relevant issue in xdg-desktop-portal: flatpak/xdg-desktop-portal#137

[ztefn]

Specific dbus interface to watch session state changes:
https://docs.flatpak.org/en/latest/portal-api-reference.html#gdbus-signal-org-freedesktop-portal-Inhibit.StateChanged

The StateChanged signal is sent to active monitoring sessions when the session state changes.

When the session state changes to 'Query End', clients with active monitoring sessions are expected to respond by calling QueryEndResponse() within a second of receiving the StateChanged signal. They may call Inhibit() first to inhibit logout, to prevent the session from proceeding to the Ending state.

Implementation in libportal appears to be Portal.session_monitor_start

When the state changes, the Portal:session-state-changed signal is emitted.

public signal void session_state_changed (bool screensaver_active, LoginSessionState session_state)

Emitted when session state monitoring is enabled and the state of the login session changes or the screensaver is activated or deactivated.

The values of this enum are returned in the Portal::session-state-changed signal to indicate the current state of the user session.

Enum values:
ENDING - the session is about to end
QUERY_END - the session is in the query end phase, during which applications can save their state or inhibit the session from ending
RUNNING - the session is running

[ztefn]

Implementation in GTK 3 (same in GTK 4, but documentation for prior version is more readable):
https://valadoc.org/gtk+-3.0/Gtk.Application.query_end.html

[ Version ( since = "3.24.8" ) ]
public signal void query_end ()

Emitted when the session manager is about to end the session, only if GtkApplication::register-session is true.

Applications can connect to this signal and call inhibit with gtk_application_inhibit_logout to delay the end of the session until state has been saved.

[ztefn]

Last few days I have tested both Gtk and LibPortal methods and it turned out inhibitors get totally ignored when the system is suspended by the user.

Also there are no QUERY_END or ENDING signals being sent when the system is suspended. Only logout and shutdown events seem to trigger those signals.

So unless the issue Inhibit portal and PrepareForSleep signal #137 in xdg-desktop-portal gets any traction I'm afraid we're stuck with using the org.freedesktop.login1 dbus interface, just like 50 other applications currently on flathub.

Please reopen or create a new issue when there is a proper replacement.