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.
Add support for command line arguments to set default values for the
various options of rivertile, bringing us back to rough feature parity
with before the commit removing the river-options protocol.
This protocol involves far too much accidental complexity. The original
motivating use-case was to provide a convenient way to send arbitrary
data to layout clients at runtime in order to avoid layout clients
needing to implement their own IPC and do this over a side-channel.
Instead of implementing a quite complex but still rigid options protocol
and storing this state in the compositor, instead we will simply add
events to the layout protocol to support this use case.
Consider the status quo event sequence:
1. send get_option_handle request (riverctl)
2. roundtrip waiting for first event (riverctl)
3. send set_foo_value request (riverctl)
4. receive set_foo_value request (river)
5. send foo_value event to all current handles (river)
6. receive foo_value event (rivertile)
7. send parameters_changed request (rivertile)
8. receive parameters_changed request (river)
9. send layout_demand (river)
And compare with the event sequence after the proposed change:
1. send set_foo_value request (riverctl)
2. receive set_foo_value request (river)
3. send set_foo_value event (river)
4. send layout_demand (river)
This requires *much* less back and forth between the server and clients
and is clearly much simpler.
Options are now all global but may be overridden per-output. If an
output local value is requested but none has been set, the global value
is provided instead. This makes for much better ergonomics when
configuring layout related options in particular.
