mutter/src/org.gnome.Mutter.DisplayConfig.xml

<!DOCTYPE node PUBLIC
'-//freedesktop//DTD D-BUS Object Introspection 1.0//EN'
'http://www.freedesktop.org/standards/dbus/1.0/introspect.dtd'>
<node>
  <!--
      org.gnome.Mutter.DisplayConfig:
      @short_description: display configuration interface

      This interface is used by mutter and gnome-settings-daemon
      to apply multiple monitor configuration.
  -->

  <interface name="org.gnome.Mutter.DisplayConfig">

    <!--
        GetResources:
	@serial: configuration serial
	@crtcs: available CRTCs
	@outputs: available outputs
	@modes: available modes
	@max_screen_width:
	@max_screen_height:

        Retrieves the current layout of the hardware.

        @serial is an unique identifier representing the current state
        of the screen. It must be passed back to ApplyConfiguration()
	and will be increased for every configuration change (so that
	mutter can detect that the new configuration is based on old
	state).

	A CRTC (CRT controller) is a logical monitor, ie a portion
	of the compositor coordinate space. It might correspond
	to multiple monitors, when in clone mode, but not that
	it is possible to implement clone mode also by setting different
	CRTCs to the same coordinates.

	The number of CRTCs represent the maximum number of monitors
	that can be set to expand and it is a HW constraint; if more
	monitors are connected,	then necessarily some will clone. This
	is complementary to the concept of the encoder (not exposed in
	the API), which groups outputs that necessarily will show the
	same image (again a HW constraint).

	A CRTC is represented by a DBus structure with the following
	layout:
	* u ID: the ID in the API of this CRTC
	* x winsys_id: the low-level ID of this CRTC (which might
	               be a XID, a KMS handle or something entirely
		       different)
	* i x, y, width, height: the geometry of this CRTC
	                         (might be invalid if the CRTC is not in
				 use)
	* i current_mode: the current mode of the CRTC, or -1 if this
	                  CRTC is not used
			  Note: the size of the mode will always correspond
			  to the width and height of the CRTC
	* u current_transform: the current transform (espressed according
	                       to the wayland protocol)
	* au transforms: all possible transforms
	* a{sv} properties: other high-level properties that affect this
	                    CRTC; they are not necessarily reflected in
			    the hardware.
			    No property is specified in this version of the API.

        Note: all geometry information refers to the untransformed
	display.

	An output represents a physical screen, connected somewhere to
	the computer. Floating connectors are not exposed in the API.
	An output is a DBus struct with the following fields:
	* u ID: the ID in the API
	* x winsys_id: the low-level ID of this output (XID or KMS handle)
	* i current_crtc: the CRTC that is currently driving this output,
	                  or -1 if the output is disabled
	* au possible_crtcs: all CRTCs that can control this output
	* s name: the name of the connector to which the output is attached
	          (like VGA1 or HDMI)
	* au modes: valid modes for this output
	* au clones: valid clones for this output, ie other outputs that
	             can be assigned the same CRTC as this one; if you
	             want to mirror two outputs that don't have each other
	             in the clone list, you must configure two different
	             CRTCs for the same geometry
	* a{sv} properties: other high-level properties that affect this
	                    output; they are not necessarily reflected in
			    the hardware.
			    Known properties:
                            - "vendor" (s): (readonly) the human readable name
                                            of the manufacturer
                            - "product" (s): (readonly) the human readable name
                                             of the display model
                            - "serial" (s): (readonly) the serial number of this
                                            particular hardware part
			    - "display-name" (s): (readonly) a human readable name
			                          of this output, to be shown in the UI
	                    - "backlight" (i): (readonly, use the specific interface)
                                               the backlight value as a percentage
                                               (-1 if not supported)
			    - "primary" (b): whether this output is primary
			                     or not
			    - "presentation" (b): whether this output is
			                          for presentation only
			    Note: properties might be ignored if not consistenly
			    applied to all outputs in the same clone group. In
			    general, it's expected that presentation or primary
			    outputs will not be cloned.

        A mode represents a set of parameters that are applied to
	each output, such as resolution and refresh rate. It is a separate
	object so that it can be referenced by CRTCs and outputs.
	Multiple outputs in the same CRTCs must all have the same mode.
	A mode is exposed as:
	* u ID: the ID in the API
	* x winsys_id: the low-level ID of this mode
	* u width, height: the resolution
	* d frequency: refresh rate
        * u flags: mode flags as defined in xf86drmMode.h and randr.h

        Output and modes are read-only objects (except for output properties),
	they can change only in accordance to HW changes (such as hotplugging
	a monitor), while CRTCs can be changed with ApplyConfiguration().

        XXX: actually, if you insist enough, you can add new modes
	through xrandr command line or the KMS API, overriding what the
	kernel driver and the EDID say.
	Usually, it only matters with old cards with broken drivers, or
	old monitors with broken EDIDs, but it happens more often with
	projectors (if for example the kernel driver doesn't add the
	640x480 - 800x600 - 1024x768 default modes). Probably something
	that we need to handle in mutter anyway.
    -->
    <method name="GetResources">
      <arg name="serial" direction="out" type="u" />
      <arg name="crtcs" direction="out" type="a(uxiiiiiuaua{sv})" />
      <arg name="outputs" direction="out" type="a(uxiausauaua{sv})" />
      <arg name="modes" direction="out" type="a(uxuudu)" />
      <arg name="max_screen_width" direction="out" type="i" />
      <arg name="max_screen_height" direction="out" type="i" />
    </method>

    <!--
        ApplyConfiguration:
	@serial: configuration serial
	@persistent: whether this configuration should be saved on disk
	@crtcs: new data for CRTCs
	@outputs: new data for outputs

	Applies the requested configuration changes.

	@serial must match the serial from the last GetResources() call,
	or org.freedesktop.DBus.AccessDenied will be generated.

	If @persistent is true, mutter will attempt to replicate this
	configuration the next time this HW layout appears.

	@crtcs represents the new logical configuration, as a list
	of structures containing:
	- u ID: the API ID from the corresponding GetResources() call
	- i new_mode: the API ID of the new mode to configure the CRTC
	              with, or -1 if the CRTC should be disabled
        - i x, y: the new coordinates of the top left corner
	          the geometry will be completed with the size information
		  from @new_mode
        - u transform: the desired transform
	- au outputs: the API ID of outputs that should be assigned to
	              this CRTC
        - a{sv} properties: properties whose value should be changed

	Note: CRTCs not referenced in the array will be	disabled.

	@outputs represent the output property changes as:
	- u ID: the API ID of the output to change
	- a{sv} properties: properties whose value should be changed

	Note: both for CRTCs and outputs, properties not included in
	the dictionary will not be changed.

	Note: unrecognized properties will have no effect, but if the
	configuration change succeeds the property will be reported
	by the next GetResources() call, and if @persistent is true,
	it will also be saved to disk.

	If the configuration is invalid according to the previous
	GetResources() call, for example because a CRTC references
	an output it cannot drive, or not all outputs support the
	chosen mode, the error org.freedesktop.DBus.InvalidArgs will
	be generated.

	If the configuration cannot be applied for any other reason
	(eg. the screen size would exceed texture limits), the error
	org.freedesktop.DBus.Error.LimitsExceeded will be generated.
    -->
    <method name="ApplyConfiguration">
      <arg name="serial" direction="in" type="u" />
      <arg name="persistent" direction="in" type="b" />
      <arg name="crtcs" direction="in" type="a(uiiiuaua{sv})" />
      <arg name="outputs" direction="in" type="a(ua{sv})" />
    </method>

    <!--
        ChangeBacklight:
	@serial: configuration serial
	@output: the API id of the output
	@value: the new backlight value

	Changes the backlight of @output to @value, which is
	expressed as a percentage and rounded to the HW limits.

        Returns the new value after rounding.
    -->
    <method name="ChangeBacklight">
      <arg name="serial" direction="in" type="u" />
      <arg name="output" direction="in" type="u" />
      <arg name="value" direction="in" type="i" />
      <arg name="new_value" direction="out" type="i" />
    </method>

    <!--
        GetCrtcGamma:
	@serial: configuration serial
	@crtc: API id of the crtc
	@red: red gamma ramp
	@green: green gamma ramp
	@blue: blue gamma ramp

	Requests the current gamma ramps of @crtc.
    -->
    <method name="GetCrtcGamma">
      <arg name="serial" direction="in" type="u" />
      <arg name="crtc" direction="in" type="u" />
      <arg name="red" direction="out" type="aq" />
      <arg name="green" direction="out" type="aq" />
      <arg name="blue" direction="out" type="aq" />
    </method>

    <!--
        SetCrtcGamma:
	@serial: configuration serial
	@crtc: API id of the crtc
	@red: red gamma ramp
	@green: green gamma ramp
	@blue: blue gamma ramp

	Changes the gamma ramps of @crtc.
    -->
    <method name="SetCrtcGamma">
      <arg name="serial" direction="in" type="u" />
      <arg name="crtc" direction="in" type="u" />
      <arg name="red" direction="in" type="aq" />
      <arg name="green" direction="in" type="aq" />
      <arg name="blue" direction="in" type="aq" />
    </method>

    <!--
        PowerSaveMode:

	Contains the current power saving mode for the screen, and
	allows changing it.

        Possible values:
	- 0: on
	- 1: standby
	- 2: suspend
	- 3: off
	- -1: unknown (unsupported)

        A client should not attempt to change the powersave mode
	from -1 (unknown) to any other value, and viceversa.
	Note that the actual effects of the different values
	depend on the hardware and the kernel driver in use, and
	it's perfectly possible that all values different than on
	have the same effect.
	Also, setting the PowerSaveMode to 3 (off) may or may
	not have the same effect as disabling all outputs by
	setting no CRTC on them with ApplyConfiguration(), and
	may or may not cause a configuration change.

        Also note that this property might become out of date
	if changed through different means (for example using the
	XRandR interface directly).
    -->
    <property name="PowerSaveMode" type="i" access="readwrite" />

    <!--
        MonitorsChanged:

	The signal is emitted every time the screen configuration
	changes.
	The client should then call GetResources() to read the new layout.
    -->
    <signal name="MonitorsChanged" />

    <!--
	GetCurrentState:
	@serial: configuration serial
	@monitors: available monitors
	@logical_monitors: current logical monitor configuration
	@properties: display configuration properties

	@monitors represent connected physical monitors

	* s connector: connector name (e.g. HDMI-1, DP-1, etc)
	* s vendor: vendor name
	* s product: product name
	* s serial: product serial
	* a(siiddada{sv}) modes: available modes
	    * s id: mode ID
	    * i width: width in physical pixels
	    * i height: height in physical pixels
	    * d refresh rate: refresh rate
	    * d preferred scale: scale preferred as per calculations
	    * ad supported scales: scales supported by this mode
	    * a{sv} properties: optional properties, including:
	       - "is-current" (b): the mode is currently active mode
	       - "is-preferred" (b): the mode is the preferred mode
	       - "is-interlaced" (b): the mode is an interlaced mode
	* a{sv} properties: optional properties, including:
	    - "width-mm" (i): physical width of monitor in millimeters
	    - "height-mm" (i): physical height of monitor in millimeters
	    - "is-underscanning" (b): whether underscanning is enabled
				      (absence of this means underscanning
				      not being supported)
	    - "max-screen-size" (ii): the maximum size a screen may have
				      (absence of this means unlimited screen
				      size)
	    - "is-builtin" (b): whether the monitor is built in, e.g. a
				laptop panel (absence of this means it is
				not built in)
	    - "display-name" (s): a human readable display name of the monitor

        Possible mode flags:
	  1 : preferred mode
	  2 : current mode


	@logical_monitors represent current logical monitor configuration

	* i x: x position
	* i y: y position
	* d scale: scale
	* u transform: transform (see below)
	* b primary: true if this is the primary logical monitor
	* a(sss) monitors: monitors displaying this logical monitor
	    * connector: name of the connector (e.g. DP-1, eDP-1 etc)
	    * vendor: vendor name
	    * product: product name
	    * serial: product serial
	* a{sv} properties: possibly other properties

	Posisble transform values:
	  0: normal
	  1: 90°
	  2: 180°
	  3: 270°
	  4: flipped
	  5: 90° flipped
	  6: 180° flipped
	  7: 270° flipped


	@layout_mode current layout mode represents the way logical monitors
	are layed out on the screen. Possible modes include:

	  1 : physical
	  2 : logical

	With physical layout mode, each logical monitor has the same dimensions
	as the monitor modes of the associated monitors assigned to it, no
	matter what scale is in use.

	With logical mode, the dimension of a logical monitor is the dimension
	of the monitor mode, divided by the logical monitor scale.


	Possible @properties are:

	* "layout-mode" (u): Represents in what way logical monitors are laid
			     out on the screen. The layout mode can be either
			     of the ones listed below. Absence of this property
			     means the layout mode cannot be changed, and that
			     "logical" mode is assumed to be used.
	    * 1 : logical  - the dimension of a logical monitor is derived from
			     the monitor modes associated with it, then scaled
			     using the logical monitor scale.
	    * 2 : physical - the dimension of a logical monitor is derived from
			     the monitor modes associated with it.
	* "supports-changing-layout-mode" (b): True if the layout mode can be
					       changed. Absence of this means the
					       layout mode cannot be changed.
	* "global-scale-required" (b): True if all the logical monitors must
				       always use the same scale. Absence of
				       this means logical monitor scales can
				       differ.
	* "legacy-ui-scaling-factor" (i): The legacy scaling factor traditionally
				          used to scale X11 clients (commonly
					  communicated via the
					  Gdk/WindowScalingFactor XSetting entry).
    -->
    <method name="GetCurrentState">
      <arg name="serial" direction="out" type="u" />
      <arg name="monitors" direction="out" type="a((ssss)a(siiddada{sv})a{sv})" />
      <arg name="logical_monitors" direction="out" type="a(iiduba(ssss)a{sv})" />
      <arg name="properties" direction="out" type="a{sv}" />
    </method>

    <!--
	ApplyMonitorsConfig:
	@serial: configuration serial
	@method: configuration method
	@logical_monitors: monitors configuration
	@properties: properties

	@method represents the way the configuration should be handled.

	Possible methods:
	  0: verify
	  1: temporary
	  2: persistent

	@logical_monitors consists of a list of logical monitor configurations.
	Each logical monitor configuration consists of:

	* i: layout x position
	* i: layout y position
	* d: scale
	* u: transform (see GetCurrentState)
	* b primary: true if this is the primary logical monitor
	* a(ssa{sv}): a list of monitors, each consisting of:
	    * s: connector
	    * s: monitor mode ID
	    * a{sv}: monitor properties, including:
	        - "enable_underscanning" (b): enable monitor underscanning;
					      may only be set when underscanning
					      is supported (see GetCurrentState).

	@properties may effect the global monitor configuration state. Possible
	properties are:

	* "layout-mode" (u): layout mode the passed configuration is in; may
			     only be set when changing the layout mode is
			     supported (see GetCurrentState).
    -->
    <method name="ApplyMonitorsConfig">
      <arg name="serial" direction="in" type="u" />
      <arg name="method" direction="in" type="u" />
      <arg name="logical_monitors" direction="in" type="a(iiduba(ssa{sv}))" />
      <arg name="properties" direction="in" type="a{sv}" />
    </method>
  </interface>
</node>