Store the previously focused surface in `state->focused` as well as in
`state->original` when starting an implicit grab. That way at the end
of an implicit grab, the detection whether the grab started and ended
on the same surface works as intended, even if the original surface was
never left at all.
Since output_destroy() calls wl_list_remove() on the output's link,
the manager must still be valid. This is the same bug fixed in bf926e3
but with a different interface.
Value is now an enum with a new value ("on-demand") that compositors can use to allow "normal" keyboard focus semantics regardless of the layer the client surface is on. An error is sent for invalid keyboard interactivity values. The old behavior is retained for clients using the previous version of the protocol.
Also adjusted the layer-shell example program to use the new keyboard interactivity options.
This function is inferior to wlr_xdg_surface_for_each_popup_surface()
for rendering as it does not iterate over subsurfaces. Furthermore,
no compositor is known to use this to iterate popups for any purpose
other than rendering. Therefore remove the function, which may of course
be reintroduced at a later date if a use-case is found.
Instead of relying on output.pending.committed, use
wlr_output_event_commit to find out whether a buffer was committed.
Eventually output.pending will be cleared before the commit event is
emitted.
References: https://github.com/swaywm/wlroots/issues/2098
This function will allow compositors to implement input handling in a
way consistent with rendering more easily.
Calling wlr_layer_surface_v1_surface_at() and checking if the result is
a wlr_xdg_popup is flawed as there may be subsurfaces in the popup tree.
This function will allow compositors to implement input handling in a
way consistent with rendering more easily.
Calling wlr_xdg_surface_surface_at() and checking if the result is a
wlr_xdg_popup is flawed as there may be subsurfaces in the popup tree.
Since device_destroy() calls wl_list_remove() on the device's link,
the manager must still be valid. However if the manager is destroyed
before the seat as the wl_display destroy handlers are called, devices
listening for the seat to be destroyed will access free'd memory in
wl_list_remove().
Since device_destroy() calls wl_list_remove() on the device's link,
the manager must still be valid. However if the manager is destroyed
before the seat as the wl_display destroy handlers are called, devices
listening for the seat to be destroyed will access free'd memory in
wl_list_remove().
- The DRM backend initially doesn't have a frame scheduled initially.
However the compositor is expected to set a mode to start the
rendering loop (frame_pending is set to true in drm_crtc_pageflip).
- The headless and X11 backends have a timer to schedule frames, so they
ignore this hint completely.
- The Wayland backend renders a fake frame to start the rendering loop.
It's the only case where a frame is pending on init, move the
assumption there.
The DRM backend adds custom modes to wlr_output.modes
Currently modes that are added after the first occurence of
wlr_output_configuration_head_v1 are not added to wlr_output_head.mode_resources.
Only wlr_output_damage works in transformed coordinates,
wlr_output->damage is in output-buffer-local coordinates.
This essentially reverts 1ecc1b5 and fixes 1477401.
Rename wlr_renderer_get_dmabuf_formats to
wlr_renderer_get_dmabuf_texture_formats. This makes it clear the formats
are only suitable for creating wlr_textures.
wlr_surface_send_enter now stores outputs that have been entered.
Combined with a new 'bind' event on wlr_output, this allows us to delay
enter events as necessary until the respective wl_output global has been
bound.
Closes: https://github.com/swaywm/wlroots/issues/2466
xdg_popups can be destroyed by the compositor when closed. When this happens,
wlroots makes the xdg_popup surface inert and resets the xdg_surface role to
NONE.
Currently, wlroots sends a protocol error and asserts that an xdg_surface has
a role when committed. This is racy if at the same time the client commits an
xdg_popup and the compositor closes it. This patch removes the assertion and
ignores commits on xdg_surfaces without a role set.
We were previously exporting DMA-BUFs when receiving the capture_output
request, and sending a done event on wlr_output.events.precommit. Instead,
export and send done on wlr_output.events.commit.
The data of a head is only sent when it is enabled. While the head was disabled
data might have been changed. In this case clients were not informed about this
change. A later enable change that does not also update the other data must
still lead to the propagation of this data.
Since we do not know what other data was changed while the head was disabled
just send together with an enable change all current data.
The protocol requires clients to set opposing anchors when requesting
a width or height of 0.
The goal of this patch is not to break clients that rely on this
behavior but to improve the consistency of the layer shell ecosystem
through adherence to the protocol.
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 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
Because wlr_renderer_blit_dmabuf() undoes y-inversion on the source
buffer, it is incorrect to pass the y-inversion flag of the source
buffer to the user.
wlr_drag sets up keyboard, pointer and touch grabs, which block 'enter'
events (and thus focus changes). For the compositor to be able to update
focus (e.g. to focus the drop target) from the destroy handler, the
grabs must be released before the destroy event is signalled.
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.
During surface finalization we may not have received a new buffer,
resetting width and height in this case is wrong since we display the
old buffer in this case.
This is necessary for some grabs, which currently have no way of knowing
when the pointer/keyboard focus has left a surface. For example, without
this, a drag-and-drop grab can erroneously drop into a window that the
cursor is no longer over.
This is the plumbing needed to properly fix swaywm/sway#5220. The
existing fix, swaywm/sway#5222, relies on every grab's `enter()` hook
allowing a `NULL` surface. This is not guaranteed by the API and, in
fact, is not the case for the xdg-shell popup grab and results in a
crash when the cursor leaves a surface and does not immediately enter
another one while a popup is open (#2161).
This fix also adds an assertion to wlr_seat_pointer_notify_enter() that
ensures it's never called with a `NULL` surface. This will make Sway
crash much more until it fixes its usage of the API, so we should land
this at the same time as a fix in Sway (which I haven't posted yet).
This fixes a crash that happens when a client requests a frame on a
backend that does not implement export_dmabuf.
An assertion fails with the message:
sway: types/wlr_output.c:777: wlr_output_lock_attach_render: Assertion
`output->attach_render_locks > 0' failed.
This introduces the enter and leave events for wlr_keyboard_group.
The enter event is emitted when a keyboard is added to the group while a
key is pressed that is not pressed by any other keyboard in the group.
The data is a wl_array of the pressed key codes unique to the keyboard
that should now be considered pressed.
Similarly the leave event is emitted when a keyboard is removed from the
group while at least one key is pressed that is not pressed by any other
keyboard in the group. The data is a wl_array of the pressed key codes
unique to the keyboard that should now be considered released.
The purpose of these events are to allow the compositor to update its
state to avoid corruption. Additionally, for the leave event, the
focused surface may have been notified of a key press for some or all of
the key codes and needs to be notified of a key release to avoid state
corruption.
These were previously emitted as normal key events, but they are not
normal key events. There is no actual key press or release associated
with the events. It's purely for state keeping purposes. Emitting them
as separate events allows the compositor to handle them differently.
Since these are purely for state keeping purposes and are not associated
with an actual key being pressed or released, bindings should not be
triggered as a result of these events.
We should throw a protocol error if the relevant capability has never
existed when get_(pointer|keyboard|touch) is called. Otherwise, it
should succeed, even if the capability is not currently present.
This follows the spec, and avoids possible races with the client when
capabilities are lost.
Closes: https://github.com/swaywm/wlroots/issues/2227
When calling assert(0) instead of returning a value, -Wreturn-type
warnings are triggered because assertions can be disabled. Replace these
assertions with abort().
This is currently inconsistent with the rest of the library and a bit of
a footgun for new compositors. However, this breaks the API in a very
unfortunate way for existing compositors.
This is necessary so that sway can determine when to start emulating
pointer events -- it shouldn't start doing so during an implicit grab,
even if the pen is over a surface that doesn't bind tablet input.
Refs swaywm/sway#5302.
In the case that only one axis received an event, rotating the input can
cause the change to actually happen on the other axis, as far as clients
are concerned.
This commit updates the axes flags to be consistent post-rotation.
Fixesswaywm/sway#4776.
A client requesting frames in the ready callback may miss frames that
happen while it is waiting to receive the event or sending the request.
If that happens, the client will have an outdated frame for an
indefinite period. A new frame might not be scheduled for a very long
time.
With this change, clients will receive new frames immediately upon
request.
Check for a NULL keyboard_state.keyboard value in
seat_client_create_keyboard() before trying to use it, as is done in
other functions like seat_client_send_repeat_info(). Prevents a segfault
in certain situations on keyboard removal, as seen in the sway issue.
Closes: https://github.com/swaywm/sway/issues/5205
Closes: https://github.com/swaywm/wlroots/issues/2073
GCC is complaining about a maybe-uninitialized variable when doing a
release build. Even if that can't actually happen because all enum
values are handled, add an abort call to silence the warning.
Most of the pending output state is not forwarded to the backend prior
to an output commit. For instance, wlr_output_set_mode just stashes the
mode without calling any wlr_output_impl function.
wlr_output_impl.commit is responsible for applying the pending mode.
However, there are exceptions to this rule. The first one is
wlr_output_attach_render. It won't go away before renderer v6 is
complete, because it needs to set the current EGL surface.
The second one is wlr_output_attach_buffer.
wlr_output_impl.attach_buffer is removed in [1].
When wlr_output_rollback is called, all pending state is supposed to be
cleared. This works for all the state except the two exceptions
mentionned above. To fix this, introduce wlr_output_impl.rollback.
Right now, the backend resets the current EGL surface. This prevents GL
commands from affecting the output after wlr_output_rollback.
This patch is required for FBO-based outputs to work properly. The
compositor might be using FBOs for its own purposes [2], having leftover
FBO state can have bad consequences.
[1]: https://github.com/swaywm/wlroots/pull/2097
[2]: https://github.com/swaywm/wlroots/pull/2063#issuecomment-597614312
Check that buffer can be scanned out in wlr_output_test instead of
wlr_output_attach_buffer. This allows the backend to have access to the
whole pending state when performing the check.
This brings the wlr_output API more in line with the KMS API.
This removes the need for wlr_output_attach_buffer to return a value,
and for wlr_output_impl.attach_buffer.
Consumers call wlr_buffer_lock. Once all consumers are done with the
buffer, only the producer should have a reference to the buffer. In this
case, we can release the buffer (and let the producer re-use it).
This fixes an assertion failure if a client tries to do this, e.g. by
creating multiple toplevel objects for the same surface. If the same
role data is set multiple times, this does not cause an error, which is
how cursors use this interface.
This patch disambiguates the needs_frame event by uncoupling it from
damage. A new separate damage event is emitted when the backend damages
the output (this happens e.g. VT is changed or software cursors are
used). The event specifies the damaged region.
The wlr_output.damage field is removed. wlr_output is no longer
responsible for tracking its own damage, this is wlr_output_damage's
job.
This is a breaking change, but wlr_output_damage users shouldn't need an
update.
Bugs fixed:
- Screen flashes on VT switch
- Cursor damage issues on the X11 and headless backends
Closes: https://github.com/swaywm/sway/issues/5086
This way, wlr_output_schedule_frame will always be followed by a
wlr_output_commit. This forces the compositor to render an extra
frame before stopping the rendering loop.
To test, run wleird's frame-callback [1], make sure it's the only
visible client on the output and check the interval between frame
events is the output's refresh period instead of zero.
[1]: https://github.com/emersion/wleird/blob/master/frame-callback.c
Closes: https://github.com/swaywm/wlroots/issues/2051
Split out the client/resource handling out of wlr_buffer by introducing
wlr_client_buffer. Make wlr_buffer an interface so that compositors can
create their own wlr_buffers (e.g. backed by GBM, like glider [1]).
[1]: c66847dd1c/include/gbm_allocator.h (L7)
This function allowed backends to provide a custom function for frame
scheduling. Before resuming the rendering loop, the DRM and Wayland
backends would wait for vsync.
There isn't a clear benefit of doing this. The only upside is that we
get more stable timings: the delay between two repaints doesn't change too
much and is close to a mutliple of the refresh rate.
However this introduces latency, especially when a client misses a
frame. For instance a fullscreen game missing vblank will need to wait
more than a whole frame before being able to display new content. This
worst case scenario happens as follows:
- Client is still rendering its frame and cannot submit it in time
- Deadline is reached
- Compositor decides to stop the rendering loop since nothing changed on
screen
- Client finally manages to render its frame, submits it
- Compositor calls wlr_output_schedule_frame
- DRM backend waits for next vblank
- The wlr_output frame event is fired, compositor draws new content on screen
- On the second next vblank, the new content reaches the screen
With this patch, the wlr_output frame event is fired immediately when
the client submits its late frame.
This change also makes it easier to support variable refresh rate, since
VRR is all about being able to present too-late frames earlier.
References: https://github.com/swaywm/wlroots/issues/1925
This makes sure the `wl_list_remove(&output_power->link)` in
`output_power_destroy()` does not crash even when the output_power never
got added to a list. This can e.g. happen in the `mgmt->output ==
output` error path of `output_power_manager_get_output_power`.
Leave positioner inverted on the individual axis if it's no longer
constrained. Otherwise constraint adjustment like `slide_x & flip_y`
could render popup outside of the screen when both axes are constrained.
FixesAlexays/Waybar#532
Port back style and naming improvements suggested in
https://github.com/swaywm/wlroots/pull/2026 for
keyboard-shortcuts-inhibit. These are all internal to the implementation
and therefore unproblematic.
Also, retrieve the inhibitor resource version from the manager resource
instead of setting it statically.
Signed-off-by: Michael Weiser <michael.weiser@gmx.de>
The keyboard shortcuts inhibitor protocol is useful for remote desktop
and virtualization software in order to request all keyboard events to
be passed to it and (almost) none being resonded to by the compositor.
This allows the session at the other end of the remote desktop
connection or inside the virtual machine to be interacted with as usual
(e.g. Alt+Tab to switch windows on the remote system instead of
locally).
Add the wayland protocol to the meson build files.
Copy'n'search'n'replace the very similar idle inhibit protocol
implementation. This already provides all the basic functionality:
- creating and destroying inhibitors upon request by a client,
- destruction in reaction to destruction of surfaces or displays,
- a list of inhibitors to search through for existing ones as well as
- a signal to be sent to the compositor upon registration of a new
inhibitor.
Beyond that we add the active and inactive events to be sent to the
client and wire those to activate and deactivate functions for the
compositor to call in confirmation of activation of a new inhibitor or
(un-)suspending of an existing inhibitor e.g. in response to a special
key combination entered by the user as suggested by the protocol.
As mandated by the protocol, we check the existance of an inhibitor for
a given surface and seat upon creation and return the error provided by
the protocol for that purpose.
Signed-off-by: Michael Weiser <michael.weiser@gmx.de>
Closes: https://github.com/swaywm/wlroots/issues/1817
Previously, if the current configuration contains an output X which is
destroyed, its head is automatically removed. If the compositor submits
the new configuration after X was removed, the current output
configuration is incorrectly detected to be the same as the previous
one, and no done event is sent. To prevent this, we can just keep track
of whether the current configuration is dirty, i.e whether we have sent
a done event for it.
This change ensures that wlr_output_transform_compose correctly composes
transforms when the first transform includes a rotation and the second
transform includes a flip.
The Wayland protocol specifies output transform rotations to be
counterclockwise and applied to the surface. Previously, wlroots
copied Weston and incorrectly made rotations act clockwise on
surfaces. This commit fixes that.
This change will break compositors which expect transform rotations
to be clockwise, and the rare applications that make use of surface
transforms.
Having 1.16 results in the following error when running the compositor:
2019-04-27 17:30:50 - [wayland] wl_global_create: implemented version for 'wl_seat' higher than interface version (7 > 6)
2019-04-27 17:30:50 - [sway/input/seat.c:428] seat_create:could not allocate seat
We require wayland-server >= 1.17 for wl_seat version 7.
Fixes: a671fc51d2 ("Advertise wl_seat version 7")
Fixes: a656e486f4 ("seat: fallback to v6 if libwayland 1.17 isn't available")
Most resources must not be NULL. Make it so callers need to check for
NULL explicitly. This makes it clearer in the handlers code that the
NULL wl_resource case needs to be handled, and allows callers to make a
difference between a NULL wl_resource and an inert resource.
This fixes a memory leak the refresh_state function for
wlr_keyboard_group. The event struct was being dynamically allocated and
never free'd. This changes it to a static allocation.
Since [1], the xdg-output description is mutable. Listen to output
description changes and send the new output description when updated.
[1]: 048102f21a
wlr_output.description is a string containing a human-readable string
identifying the output. Compositors can customise it via
wlr_output_set_description, for instance to make the name more
user-friendly.
References: https://github.com/swaywm/wlroots/issues/1623
Bumps minimum version to 0.51.0
- Remove all intermediate static libraries.
They serve no purpose and are just add a bunch of boilerplate for
managing dependencies and options. It's now managed as a list of
files which are compiled into libwlroots directly.
- Use install_subdir instead of installing headers individually.
I've changed my mind since I did that. Listing them out is annoying as
hell, and it's easy to forget to do it.
- Add not_found_message for all of our optional dependencies that have a
meson option. It gives some hints about what option to pass and what
the optional dependency is for.
- Move all backend subdirectories into their own meson.build. This
keeps some of the backend-specific build logic (especially rdp and
session) more neatly separated off.
- Don't overlink example clients with code they're not using.
This was done by merging the protocol dictionaries and setting some
variables containing the code and client header file.
Example clients now explicitly mention what extension protocols they
want to link to.
- Split compositor example logic from client example logic.
- Minor formatting changes
In case the texture can't be imported, release the buffer so that the
client can submit another one. In case the allocation fails, disconnect
the client.
Some globals are static and it doesn't make sense to destroy them before
the wl_display. For instance, wl_compositor should be created before the
display is started and shouldn't be destroyed.
For these globals, we can simplify the code by removing the destructor
and stop keeping track of wl_resources (these will be destroyed with the
wl_display by libwayland).
Most of the time, compositors just display the surface's current buffer
on an output. Add an helper to make it easy to support presentation-time
in this case.
The wlr_presentation_feedback struct now tracks presentation feedback
for multiple resources (but still a single surface content update). This
allows the compositor to properly send presentation events even when
there is more than one frame of latency or when it references a
surface's buffer.
Backends not supporting presentation feedback call
wlr_output_send_present with a NULL event in their commit handler. Since
the commit hasn't been applied yet, commit_seq still has its old value.
We need to increment it.
An alternative would be to move commit_seq in wlr_output_state. This
would allow to have a pending and a current commit_seq.
wlr_output_send_present could take the pending commit_seq when called
with a NULL event.
This requires functions without a prototype definition to be static.
This allows to detect dead code, export less symbols and put shared
functions in headers.
This is set to the value of wlr_output.commit_seq when the frame has
been submitted. This allows tracking presentation with more then 1 full
frame of latency.
References: https://github.com/swaywm/wlroots/issues/1917
A wlr_keyboard_group allows for multiple keyboard devices to be
combined into one logical keyboard. Each keyboard device can only be
added to one keyboard group. This helps with the situation where one
physical keyboard is exposed as multiple keyboard devices. It is up to
the compositors on how they group keyboards together, if at all.
Since a wlr_keyboard_group is one logical keyboard, the keys are a set.
This means that if a key is pressed on multiple keyboard devices, the
key event will only be emitted once, but the internal state will count
the number of devices that the key is pressed on. Likewise, the key
release will not be emitted until the key is released from all devices.
If the compositor wants access to which keys are pressed and released
on each keyboard device, the events for those devices can be listened
to, as they currently are, in addition to the group keyboard's events.
Also, all keyboard devices in the group must share the same keymap. If
the keymap's differ, the keyboard device will not be able to be added
to the group. Once in the group, if the keymap or effective layout for
one keyboard device changes, it will be synced to all keyboard devices
in the group. The repeat info and keyboard modifiers are also synced
If box->width/height is <= 0, the box doesn't contain any points, and so
there is no closest point. wlr_box_closest_point should return NAN in this
case.
In addition, we need to handle empty boxes in a few other
output-layout-related places, because outputs can have size 0x0 when
they are created or destroyed.
Since e26217c51e3a5e1d7dfc95a8a76299e056497981, touchpoints can outlive
surfaces. This works fine as long as the client stays around, but fails
horribly otherwise; therefore we have to make sure that touchpoints don't
outlive their clients.
Fixes#1788
When the surface is closed, we destroy all pending serials waiting to be
accepted. This means we need to ignore any future ack events, because we
can have the following events:
1. -> configure()
2. -> close()
3. <- ack_configure()
At point 3, wlroots will error the client because of invalid serial,
however the client hasn't processed close() yet.
This destroys the xdg popups associated with a layer surface when the
layer surface is unmapped. It does not make sense to keep the popups
open when unmapped.
From the xdg-shell specification:
If the parent is unmapped then its children are managed as
though the parent of the now-unmapped parent has become the
parent of this surface. If no parent exists for the now-unmapped
parent then the children are managed as though they have no
parent surface.
It's added to manager->input_methods list in manager_get_input_method, but
wasn't removed anywhere, leading to possible use-after-free in
wlr_input_method_manager_v2_destroy.
This adds support for xdg-output-unstable-v1 version 3, added in [1].
The xdg_output.done event is now deprecated and is replaced with
wl_output.done.
[1]: 962dd53537
This commit makes more output properties (mode, enabled, scale and transform)
atomic. This means that they are double-buffered and only applied on commit.
Compositors now need to call wlr_output_commit after setting any of those
properties.
Internally, backends still apply properties sequentially. The behaviour should
be exactly the same as before. Future commits will update some backends to take
advantage of the atomic interface. Some backends are non-atomic by design, e.g.
the X11 backend or the legacy DRM backend.
Updates: https://github.com/swaywm/wlroots/issues/1640
This prevents screencopy applications from hanging because a failed
event never got sent when the output was disconnected or disabled after
the call to buffer().
Disconnecting or disabling an output between capture_output() and
ready() could cause either a NULL dereference or an incorrect
attach_render_locks count.
The documentation for wayland-server.h says:
> Use of this header file is discouraged. Prefer including
> wayland-server-core.h instead, which does not include the server protocol
> header and as such only defines the library PI, excluding the deprecated API
> below.
Replacing wayland-server.h with wayland-server-core.h allows us to drop the
WL_HIDE_DEPRECATED declaration.
AFAIK this was always set to zero. Instead, compute wl_output mode flags on the
fly.
Technically this is a breaking change, but I don't think anybody uses this
field.
When the surface is destroyed clear it's reference but wait for the up
event to destroy the touch point via wlr_seat_touch_notify_up().
If the surface is destroyed before the up event we end up with
incomplete sequences sent to the client like
[915821.276] wl_touch@3.down(146, 2475027, wl_surface@38, 0, 236.000000, 515.000000)
[915821.608] wl_touch@3.frame()
[915821.637] wl_touch@3.motion(2475027, 0, 236.000000, 515.000000)
[915821.779] wl_touch@3.frame()
so there's never an up event. While it should be something like
[2461229.051] wl_touch@3.down(81, 3236959, wl_surface@34, 0, 218.000000, 478.000000)
[2461229.435] wl_touch@3.frame()
[2461229.484] wl_touch@3.motion(3236959, 0, 218.000000, 478.000000)
[2461229.636] wl_touch@3.frame()
[2461277.520] wl_touch@3.up(82, 3237007, 0)
[2461277.681] wl_touch@3.frame()
this confuses toolkits intepreting the next down event incorrectly. So
don't destroy the touch point too early.
This change tracks, for each wlr_seat_client, the most recent serial
numbers which were sent to the client. When the client makes a
selection request, wlroots now verifies that the serial number
associated with the selection request was actually provided to that
specific client. This ensures that the client that was most
recently interacted with always has priority for its copy selection
requests, and that no other clients can incorrectly use a larger serial
value and "steal" the role of having the copy selection.
Also, the code used to determine when a given selection is superseded
by a newer request uses < instead of <= to allow clients to make
multiple selection requests with the same serial number and have the
last one hold.
To limit memory use, a ring buffer is used to store runs of sequential
serial numbers, and all serial numbers earlier than the start of the
ring buffer are assumed to be valid. Faking very old serials is
unlikely to be disruptive.
Assuming all clients are correctly written, the only additional
constraint which this patch should impose is that serial numbers
are now bound to seats: clients may not receive a serial number
from an input event on one seat and then use that to request
copy-selection on another seat.
The backend doesn't need to handle transform changes, since everything is done
in software. In fact, all of the implementations were all identical and just
set the transform.
We could add support for hardware transforms, but:
- This would require a different field (something like hardware_transform)
- Not all combinations are possible because there often are hardware
limitations
- The Wayland protocol isn't ready for this (in particular xdg-output, see [1])
This belongs to a different patch series anyway.
[1]: https://patchwork.freedesktop.org/series/52324/
It can be surprising for callers to stash pending changes, commit, get a
failure, then set some other pending changes, commit again, and get another
failure because of the previously-pending changes.
Instead, make commit reset the pending state on failure.
In addition to `button_count`, we keep track of the current buttons
pressed just as in `wlr_keyboard`.
Add `set_add` and `set_remove` to assist with this. These functions can
only be used with values greater than 0 (such as the button/key masks
for keyboards and pointers).
Partially addresses:
- https://github.com/swaywm/wlroots/issues/1716
- https://github.com/swaywm/wlroots/issues/1593
