KDE output management

Configuration of server outputs through clients

This interface enables clients to set properties of output devices for screen configuration purposes via the server. To this end output devices are referenced by global org_kde_kwin_outputdevice objects.

outputmanagement (wl_global) -------------------------- request: * create_configuration -> outputconfiguration (wl_resource)

outputconfiguration (wl_resource) -------------------------- requests: * enable(outputdevice, bool) * mode(outputdevice, mode_id) * transformation(outputdevice, flag) * position(outputdevice, x, y) * apply

events: * applied * failed

The server registers one outputmanagement object as a global object. In order to configure outputs a client requests create_configuration, which provides a resource referencing an outputconfiguration for one-time configuration. That way the server knows which requests belong together and can group them by that.

On the outputconfiguration object the client calls for each output whether the output should be enabled, which mode should be set (by referencing the mode from the list of announced modes) and the output's global position. Once all outputs are configured that way, the client calls apply. At that point and not earlier the server should try to apply the configuration. If this succeeds the server emits the applied signal, otherwise the failed signal, such that the configuring client is noticed about the success of its configuration request.

Through this design the interface enables atomic output configuration changes if internally supported by the server.

create_configuration(id: new_id<org_kde_kwin_outputconfiguration>)
Argument
Type
Description
idnew_id<org_kde_kwin_outputconfiguration>
Provide outputconfiguration object for configuring outputs

Request an outputconfiguration object through which the client can configure output devices.


Configure single output devices

outputconfiguration is a client-specific resource that can be used to ask the server to apply changes to available output devices.

The client receives a list of output devices from the registry. When it wants to apply new settings, it creates a configuration object from the outputmanagement global, writes changes through this object's enable, scale, transform and mode calls. It then asks the server to apply these settings in an atomic fashion, for example through Linux' DRM interface.

The server signals back whether the new settings have applied successfully or failed to apply. outputdevice objects are updated after the changes have been applied to the hardware and before the server side sends the applied event.

Argument
Type
Description
outputdeviceobject<org_kde_kwin_outputdevice>
outputdevice to be en- or disabled
enableint
1 to enable or 0 to disable this output
Enable or disable an output

Mark the output as enabled or disabled.

Argument
Type
Description
outputdeviceobject<org_kde_kwin_outputdevice>
outputdevice this mode change applies to
mode_idint
aspired mode's id
Switch outputdevice to mode

Sets the mode for a given output by its mode size (width and height) and refresh rate.

Argument
Type
Description
outputdeviceobject<org_kde_kwin_outputdevice>
outputdevice this transformation change applies to
transformint
transform enum
Transform outputdevice

Sets the transformation for a given output.

position(outputdevice: object<org_kde_kwin_outputdevice>, x: int, y: int)
Argument
Type
Description
outputdeviceobject<org_kde_kwin_outputdevice>
outputdevice this position applies to
xint
position on the x-axis
yint
position on the y-axis
Position output in global space

Sets the position for this output device. (x,y) describe the top-left corner of the output in global space, whereby the origin (0,0) of the global space has to be aligned with the top-left corner of the most left and in case this does not define a single one the top output.

There may be no gaps or overlaps between outputs, i.e. the outputs are stacked horizontally, vertically, or both on each other.

Argument
Type
Description
outputdeviceobject<org_kde_kwin_outputdevice>
outputdevice this mode change applies to
scaleint
scaling factor
Set scaling factor of this output

Sets the scaling factor for this output device.

apply()
Apply configuration changes to all output devices

Asks the server to apply property changes requested through this outputconfiguration object to all outputs on the server side.

Argument
Type
Description
outputdeviceobject<org_kde_kwin_outputdevice>
outputdevice this mode change applies to
scalefixed
scaling factor
Set scaling factor of this output

Sets the scaling factor for this output device. Sending both scale and scalef is undefined.

colorcurves(outputdevice: object<org_kde_kwin_outputdevice>, red: array, green: array, blue: array)
Argument
Type
Description
outputdeviceobject<org_kde_kwin_outputdevice>
outputdevice curves apply to
redarray
red color ramp
greenarray
green color ramp
bluearray
blue color ramp
Set output color curves

Set color curves of output devices through RGB color ramps. Allows color correction of output device from user space.

These are the raw values. A compositor might opt to adjust these values internally, for example to shift color temperature at night.

destroy()
Release the outputconfiguration object
Argument
Type
Description
outputdeviceobject<org_kde_kwin_outputdevice>
outputdevice overscan applies to
overscanuint
overscan value
Set overscan value

Set the overscan value of this output device with a value in percent.

Argument
Type
Description
outputdeviceobject<org_kde_kwin_outputdevice>
outputdevice this VRR policy applies to
policyuint<org_kde_kwin_outputconfiguration.vrr_policy>
the vrr policy to apply
Set the VRR policy

Set what policy the compositor should employ regarding its use of variable refresh rate.

applied()
Configuration changes have been applied

Sent after the server has successfully applied the changes. .

failed()
Configuration changes failed to apply

Sent if the server rejects the changes or failed to apply them.

vrr_policy { never, always, automatic } 
Argument
Value
Description
never0
always1
automatic2
Describes vrr policy

Describes when the compositor may employ variable refresh rate


SPDX-FileCopyrightText: 2008-2011 Kristian Høgsberg SPDX-FileCopyrightText: 2010-2011 Intel Corporation SPDX-FileCopyrightText: 2012-2013 Collabora, Ltd. SPDX-FileCopyrightText: 2015 Sebastian Kügler <sebas@kde.org>

SPDX-License-Identifier: MIT-CMU