KDE external brightness

kde_external_brightness_v1

version 2

external brightness control

Some brightness control mechanisms are somewhat unstable, or require root privileges, so putting them inside of the compositor is not desired. This protocol is for outsourcing the actual brightness-setting to a process outside of the compositor.

kde_external_brightness_v1::destroy

Type: destructor

destroy()

Destroy the object.

kde_external_brightness_v1::create_brightness_control

create_brightness_control(id: new_id<kde_external_brightness_device_v1>)

Argument	Type	Description
id	new_id<kde_external_brightness_device_v1>

registers a brightness device with the compositor

kde_external_brightness_device_v1

version 2

brightness control device

After creating this object, the client should issue all relevant setup requests (set_internal, set_edid, set_max_brightness, optionally set_observed_brightness) and finish the sequence with commit. Afterwards, for each change in values, the client must call commit again.

kde_external_brightness_device_v1::destroy

Type: destructor

destroy()

destroy the object and unregister the brightness control device

kde_external_brightness_device_v1::set_internal

set_internal(internal: uint)

Argument	Type	Description
internal	uint	1 if it's an internal panel, 0 if not

sets whether or not the brightness device belongs to an internal display

kde_external_brightness_device_v1::set_edid

set_edid(string: string)

Argument	Type	Description
string	string	base-64 encoded string of the first 128 bytes of the EDID

set the EDID data for identification of the display

kde_external_brightness_device_v1::set_max_brightness

set_max_brightness(value: uint)

Argument	Type	Description
value	uint	the maximum value that can be set

notifies the compositor of the maximum brightness that can be set on this device

kde_external_brightness_device_v1::commit

commit()

notifies the compositor that all relevant identifiers and values have been sent

kde_external_brightness_device_v1::set_observed_brightness

since 2

set_observed_brightness(value: uint)

Argument	Type	Description
value	uint	the observed value that was read

notifies the compositor of the brightness that was read from this device

The client can set this to notify the compositor of the device's initial brightness. It can also set this again after the initial commit to notify the compositor that the brightness level has changed due to external factors. The compositor is free to use or ignore this value as it sees fit.

kde_external_brightness_device_v1::requested_brightness

requested_brightness(value: uint)

Argument	Type	Description
value	uint	the value to set the device to

requests the client to change the brightness to this value

The client must ensure that if the brightness level changes due to external factors, that it either overwrites those changes with what the compositor last requested, or commit again with set_observed_brightness specifying the changed brightness.

Compositor Support

	Mutter 47.3	KWin 6.2	Sway 1.10	COSMIC 0.1	Hyprland 0.42.0	niri 25.01	Weston 13	Mir 2.19	GameScope 3.15.14	Jay 1.7.0
kde_external_brightness_v1	x	1	x	x	x	x	x	x	x	x

Copyright

SPDX-FileCopyrightText: 2024 Xaver Hugl <xaver.hugl@gmail.com>

SPDX-License-Identifier: MIT-CMU