The resource field of wlr_xdg_positioner is never initialized or
accessed within wlroots. The wl_resource for this interface is stored
in the wlr_xdg_positioner_resource struct.
This brings the layer-shell api in line with that of xdg-shell and
avoids reimplementing this function in every compositor in order to
render layer shell popups correctly.
This type is meant to be 4 bytes large as seen in _XcursorReadUInt which
always reads 4 bytes. An unsigned int is often 4 bytes large but this
isnt' guaranteed so it is cleaner to use the exact type we want.
This event contains a `committed` bitfield, which allows callers to know
which output fields changed during the commit.
This allows users to setup a single atomic commit listener, instead of
setting up one listener for each event (mode, scale, transform, and so
on).
References: https://github.com/swaywm/wlroots/issues/2098
These states are distinct in the time period between the ack_configure
and the next commit on the surface. Splitting these states avoids the
following race for example:
- client starts at 1000x1000
- wlr_xdg_toplevel_set_size 500x500
- size is different -> configure sent
- client acks the configure
- wlr_xdg_toplevel_set_size 1000x1000
- compare_xdg_toplevel_state returns true since there is no pending
configure and the currently committed size is still 1000x1000
- no new configure is sent
- client commits at the size it last acked, 500x500
Certain clients require this property to be set for expected behavior.
Most notably, steam client CSD maximize button no longer worked
after unmaximizing once, unless the state was changed by another
method. The state is unset whenever another surface gains focus.
The output backend API is now mostly state-less thanks to the atomic
hooks (commit and test). There is one exception though: attach_render.
This function makes the rendering context current. However sometimes the
compositor might decide not to render after attach_render (e.g. when
there's nothing new to render to the back buffer). Thus
wlr_output_rollback has been introduced to revert the pending state.
Because the output backend API is mostly state-less, the only thing
wlr_output_impl.rollback needs to do is revert the current rendering
context. Rename the function to rollback_render to make this clear. Add
a check in the common wlr_output code to only call rollback_render when
attach_buffer has been previously called.
On the long term, we'll be able to remove attach_render and
rollback_render together.
