We use the PMF syntax so the isValid() check is unnecessary as the
compiler will notify about wrong signal at compile time. It makes
writing autotests feel less boilerplaty.
This makes KWin switch to in-tree copy of KWaylandServer codebase.
KWaylandServer namespace has been left as is. It will be addressed later
by renaming classes in order to fit in the KWin namespace.
The main reason why we have factory methods is that up to some point,
kwayland had its own signal to indicate when globals have to be removed.
Now that all globals add destroy listeners for the wl_display object,
we don't have that signal. Most factory methods are equivalent to doing
new T(display).
Besides adding unnecessary boilerplate code, another reason to get rid
of the factory methods is to reduce the amount of merge conflicts. If
several persons work on implementing wayland protocols at the same time,
sooner or later someone will have to resolve merge conflicts in Display.
libwayland-server allows the wl_display accept client connections on
more than one socket. We currently don't listen on multiple sockets,
but it would be nice if Display supported such operation mode.