If the display resolution *is* 800x600, using this size is bad since
there will typically be panels and other things on the screen too.
Not that 800x600 is something we expect to see in real life, but may
happen on virtual displays.
When resizing the window under mutter, mutter seems to expect a
configure ack *and* a surface commit *right* away, or things get out
of sync.
Unlike kwin, which is requires a commit for each configure ack, but is
fine with having the commit arrive later (after we've rendered it),
mutter is not.
I even tried delaying the configure ack until just before the commit,
but still no go.
So for now, detect when we're running under mutter and always do a
surface commit right away.
This can *not* be done on any other compositor as it breaks the CSD
and main surface synchronization; we've resized the CSDs, but not the
main surface.
I.e. this *should* not work, but for some reason is the *only* way to
make things work on mutter.
Interestingly, doing it any other way on mutter causes visual
glitches; window jumping around when resizing, or de-synchronized
CSDs/main surface.
When there is no configuration file, and we're using the default
configuration, we accidentally jumped pasted the code that ensures
we have at least "monospace" in the font list.
When the compositor wants us to decide the size (it sends a configure
event with width/height == 0), then use the last unmaximized size, if
there is one.
If there isn't one, use the size from the user configuration.
When we position CSDs inside the main surface, and CSDs are switched
on run-time, we need to force a grid resize, since the actual window
content will now be smaller.
Alternative solution: call resize with width/height increased, to
account for the CSDs. This would increase the window size, but would
keep the grid size fixed.
Up until now, we've centered the grid on the main surface. Meaning, we
calculated the unusable area, added the user configured padding and
then centered the grid.
This may look nice at first, but doesn't anymore when you start
resizing the window. Resizing the window will cause the top+left
margins to change, which makes the text "jump" or "wobble".
So, now we fix the grid in the upper left corner defined by the user
configured padding (plus CSDs if they aren't positioned outside the
main surface).
The size (width, height) arguments provided by the compositor in the
XDG toplevel configure event *include* the surrounding CSDs.
Since our code assumes the size is for the main surface only (and then
positions the sub-surfaces *outside* the main surface), adjust the
provided size when using CSDs.
This ensures our actual window size ends up being what the compositor
wants it to be, and it fixes resize-glitches when resizing using CSDs.
While most compositors handle instantiated but not-yet-mapped
sub-surfaces correctly, e.g. kwin does not.
For example, it will incorrectly offset the main surface both
horizontally and vertically with a couple of pixels, leaving two
transparent areas at the top and left, between the SSDs and the main
surface.
Note that a workaround is to position the sub-surfaces inside the main
surface while they're unmapped. However, since the surfaces may be
larger than the main surface (the CSDs, for examples, always are),
this doesn't quite work since kwin, at least, resizes the window to
include the sub-surfaces, even when unmapped.
So, instead we instantiate all sub-surfaces on demand, when we know
where to position them, and when they should be mapped.
For now, this behavior is controlled with an ifdef. At least kwin
seems very buggy when the decorations are positioned like this (but
normally you'd use server-side decorations with kwin anyway).
This commit also changes 'use_csd' to be a tri-state variable;
when instantiating a window it is set to 'unknown'.
If there's no decoration manager available (e.g. weston), we
immediately set it to 'yes' (use CSDs).
Otherwise, we wait for the decoration manager callback to indicate
whether we should use CSDs or not.
We draw the CSDs in a darker color when we're inactive.
Weston seems to be buggy with synchronized subsurfaces, so temporarily
reconfigure them to desynchronized surfaces.
