This also removes the (unimplemented) possibility to change a window to
non-native. This seems generally not very useful, and there are some problems
with it, for instance if two "users" need a window to be native and then
one of the "users" doesn't need it anymore it can't change it back, because
it is unaware of the other reason the window is native.
If a native window or a window with a native subwindow is moved or resized
then the client window moves and implicit paints need to be flushed since
the native window move will copy/overwrite data. This may happen while there
is an outstanding paint if the move is inside an expose event (weird, but
flash embedded in webkit hit this).
Right now we're asserting here, but the right fix is to allow this but
to not flush the parts that are currently in a (non-implicit) paint. This
means we flush all results from previous not-yet-flushed exposes, but not
the ones being drawn.
In the new world offscreen windows are not put in the hierarchy, but are
rather toplevels for themselves. Offscreen hooks don't make any sense
in this model.
It often happens that we move region A to B and then we move a subset
of B to C. When possible we'd like to replace this with a move from
A directly to C, and a suplimentary move from A to the areas of B not
overwritten by C.
Getting an optimal move combiner seems quite complicated, but this
simple approach gets most of the interesting cases right and isn't
all to complicated.
There is no need to copy something that is already invalid and will
be marked as invalid in the destination anyway, so we remove this
area from the region to copy.
The expose translation is useful for tracking how outstanding
invalid (exposed on server) areas are copied, and how we need to
compensate for that on the client side to redraw the right area.
So, we should queue the translation at the time we actually move
the bits on the server side, not when moving the window on the
client side.
Also, clean up some naming of parameters.
We now copy outstanding window moves directly on the window and
not to an intermediary pixmap, this means our previous code to
combine window copies was wrong (it relied on each copy not
destroying the source date).
Furthermore, we can't just remove all the update area from the
destination of the outstanding moves, as sometimes things get
copied into that area and then used as the source of another
copy.
We replace the previous window copy combining with a naive
version that just queues each move, just to get things right.
Further work to optimize copies is possible.
Also, we don't remove copy destinations that are used as source
for later copies.
We also clean up the memory management by not having
move_region_on_impl taking ownership of the passed in region.
Apps that set no exposure mask rely on the system clearing things
to the window background, so we need to do this ourselves.
Also, don't do this on foreign windows, as they are not controlled
by us. In fact don't do exposes on foreign windows either.
This is required for the GtkSocket code, as it shows the plug child
even though the current cached state is (wrongly) that its already
mapped.
This makes blink work for non-local case in testsocket.
Native descendants of a virtual children are not automatically destroyed
with the parent as if it was a native window, so we need to handle
the native recursion tracking manually in _gdk_window_destroy_hierarchy()
Some apps really need to set custom event masks on native child windows,
for example emacs sets the event masks with gdk, but then reads out
the raw X events via a filter, so gdk event emulation doesn't work for that.
When we get motion or button events we map back from the event position and
window to the toplevel before doing anything, because a toplevel native window
could e.g. overlap a child window or whatever.
These are generated when we get an implicit grab on a native
child window, and we can't filter them with _has_grab() because
they are sent before the button press event where we detect
the implicit grab.
This makes clicks work in the flash plugin again
It turns out we really have to ignore grab/ungrab events or we'll
report double crossing events when we grab or ungrab.
However, we also can't ignore crossing events from grabs from other clients
as that leads to missed enter/leave events on e.g. alt-tab in metacity.
Fortunately we now track grabs very precisely, so we know with certainty
whether we have a grab at the time (serial) of the native crossing events,
and only if we do we ignore them.
If we get crossing events with subwindow unexpectedly being NULL
that means there is a native subwindow that gdk doesn't know about.
We track these and forward them, with the correct virtual window
events inbetween.
This is important to get right, as metacity uses gdk for the frame
windows, but gdk doesn't know about the client windows reparented
into the frame.
Having GDK_WINDOW_CHILD windows with root as the parent apparently works,
and metacity uses it. The current gdk_window_get_toplevel() returns the
root window for that, which is wrong, so we check that explicitly.
This causes all sorts of weirdness with pointer_over_window
being the rootwindow and then crashing gdk_window_get_toplevel() later.
With this metacity stops crashing madly.
