KSld connects to the DBus signals for the OnScreenDisplay and forwards
them to the greeter application through the private Wayland protocol.
The idea here is to not have the greeter connect to the DBus as in future
it would be preferable if the greeter cannot connect to DBus.
The lookandfeel package might expose an object called "onScreenDisplay".
Whenever an OSD message is recieved by the greeter it looks for such an
object and updates the osd specific properties.
The default breeze lookandfeel package integrates the OsdItem from the
same lookandfeel package.
REVIEW: 122452
The screenlocker_greet needs to tell the parent ksld process which
windows it created. Ksld sends input events to these windows. So
far this was based on an X property on the window. Unfortunately
ksld didn't validate whether the windows tagged with this property
belong to the screenlocker_greet process it started.
With this change the communication for announcing windows is moved
away from the X11 protocol and instead a custom Wayland protocol is
used.
Ksld starts a KWaylandServer when the greet process gets started. It
creates anonymous unix sockets for the connection and passes one
filedescriptor to the started greeter process.
The check for the X property is removed in ksld and instead only
windows ids passed through the Wayland socket connection are
accepted.
REVIEW: 121429