Normally, we resize and update the font's DPI whenever our window
enters or leaves an output.
This is since a change in the outputs we're mapped on means the scale
factor to use, or the DPI to use for the fonts may have changed.
However, a special case is when we're removed from the last
output. This should only happen at shutdown, when we're un-mapping
ourselves.
In this case, we typically don't have a access to e.g. the PTMX
fd (often, the reason we're shutting down is because the client
exited). This resulted in (harmless) error messages when emitting the
TIOCSWINSZ event.
Since we're shutting down anyway, we can simply skip the resize and
everything. This gets rid of the error message, and also means we're
shutting down faster.
When the user left-clicks the title-bar, we start a timer. When the
timer has elapsed, we initiate a 'move' operation.
However, if the user clicked, and then started dragging right away,
there was a very visible lag since we waited for the timeout before
starting the move.
Now, on a pointer motion event we detect a running 'move' timer, and
abort it and instead start the 'move' operation right away.
I'm not sure why I added this in the first place... our cursor doesn't
depend on keyboard focus.
Furthermore, with CSDs, we may get keyboard enter events for the CSD
surfaces, and these should definitely *not* update the xcursor
as if it was inside the main surface.
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).
