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.
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
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.
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
To prevent wl_keyboard keymap being written to by clients, use a unique
file descriptor for each wl_keyboard resource.
Reference: weston, commit 76829fc4eaea329d2a525c3978271e13bd76c078
wlr_keyboard manages the xkb-common state of the compositor.
It used to update the state, update the modifiers, then notify the
compositor.
When [Shift_L] was pressed and released, this resulted in an event chain:
Modifiers: Shift
Key: Shift_L (Pressed)
Modifiers:
Key: Shift_L (Release)
The xkb-docs state that the state should be updated *after* the key was
handled [1], to prevent the new state from influencing the actual key
generated.
To achieve this, the event to the compositor is emitted, *before*
wlroots handles the xkb and internal keyboard state.
With this patch applied, the emitted events ill be:
Modifiers:
Key: Shift_L (Pressed)
Modifiers: Shift
Key: Shift_L (Release)
[1] https://xkbcommon.org/doc/current/group__state.html#gac554aa20743a621692c1a744a05e06ce
keymap_size is a size_t. Otherwise the build fails on arm like
../types/wlr_keyboard.c: In function 'wlr_keyboard_set_keymap':
../include/wlr/util/log.h:34:17: error: format '%lu' expects argument of type 'long unsigned int', but argument 5 has type 'size_t {aka unsigned int}' [-Werror=format=]
_wlr_log(verb, "[%s:%d] " fmt, _strip_path(__FILE__), __LINE__, ##__VA_ARGS__)
^
../types/wlr_keyboard.c:218:3: note: in expansion of macro 'wlr_log'
wlr_log(L_ERROR, "creating a keymap file for %lu bytes failed", kb->keymap_size);
^~~~~~~
../types/wlr_keyboard.c:218:50: note: format string is defined here
wlr_log(L_ERROR, "creating a keymap file for %lu bytes failed", kb->keymap_size);
~~^
%u
