A true "default" config doesn't make sense for river. Everyone who uses
river seriously will customize their init script. Futhermore, the
current behavior of embedding the install path of the default system
config in the river binary is complex and prone to breaking.
On output change, if the cursor is not already on the newly focused
output, it will now be warped to its center. The check is necessary,
since focusing outputs with the pointer will be implemented in
the future.
A client is free to change its mind and request a different
size/anchor/etc after recieving the initial configure but before
attaching and committing the first buffer. This means that we should
respond to such a situation with a new configure.
mako has been observed doing this in the wild for example.
Currently in handleUnmap() we call View.unmap() before removing
listeners. However View.unmap() may destroy the view before returning
if the transaction started doesn't have to wait on any configures.
To ensure that we don't try to remove listeners which have already been
free'd, do this before calling View.unmap().
The Layout struct holds a pointer to the Output which becomes invalid
when the Output is destroyed so we must ensure all the layouts of an
Output are destroyed first.
The transaction system exists to coordinate size changes of all views
in a layout in order to achieve frame perfection. Since many clients
do not need to commit a new buffer in response to a activated state
change alone, this breaks things when such a configure event is tracked
by the transaction system. Instead, simply send activated and fullscreen
configures right away but still track this state in a double-buffered
way so that e.g. border color changes based on focus are frame-perfect.
This also fixes a related issue with the transaction system where views
that did not need to commit in response to our first configure were not
rendered until their next frame.
