path: root/protocol/wayland.xml

<?xml version="1.0" encoding="UTF-8"?>
<protocol name="wayland">

  <copyright>
    Copyright © 2008-2011 Kristian Høgsberg
    Copyright © 2010-2011 Intel Corporation

    Permission to use, copy, modify, distribute, and sell this
    software and its documentation for any purpose is hereby granted
    without fee, provided that the above copyright notice appear in
    all copies and that both that copyright notice and this permission
    notice appear in supporting documentation, and that the name of
    the copyright holders not be used in advertising or publicity
    pertaining to distribution of the software without specific,
    written prior permission.  The copyright holders make no
    representations about the suitability of this software for any
    purpose.  It is provided "as is" without express or implied
    warranty.

    THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS
    SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
    FITNESS, IN NO EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY
    SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
    WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
    AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
    ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
    THIS SOFTWARE.
  </copyright>

  <interface name="wl_display" version="1">
    <description summary="core global object">
      The core global object.  This is a special singleton object.  It
      is used for internal Wayland protocol features.
    </description>

    <request name="sync">
      <description summary="asynchronous roundtrip">
	The sync request asks the server to emit the 'done' event
	on the returned wl_callback object.  Since requests are
	handled in-order and events are delivered in-order, this can
	used as a barrier to ensure all previous requests and the
	resulting events have been handled.
      </description>
      <arg name="callback" type="new_id" interface="wl_callback"/>
    </request>

    <request name="get_registry">
      <description summary="get global registry object">
	This request creates a registry object that allows the client
	to list and bind the global objects available from the
	compositor.
      </description>
      <arg name="callback" type="new_id" interface="wl_registry"/>
    </request>

    <event name="error">
      <description summary="fatal error event">
	The error event is sent out when a fatal (non-recoverable)
	error has occurred.  The object_id argument is the object
	where the error occurred, most often in response to a request
	to that object.  The code identifies the error and is defined
	by the object interface.  As such, each interface defines its
	own set of error codes.  The message is an brief description
	of the error, for (debugging) convenience.
      </description>
      <arg name="object_id" type="object"/>
      <arg name="code" type="uint"/>
      <arg name="message" type="string"/>
    </event>

    <enum name="error">
      <description summary="global error values">
	These errors are global and can be emitted in response to any
	server request.
      </description>
      <entry name="invalid_object" value="0"
	     summary="server couldn't find object"/>
      <entry name="invalid_method" value="1"
	     summary="method doesn't exist on the specified interface"/>
      <entry name="no_memory" value="2"
	     summary="server is out of memory"/>
    </enum>

    <event name="delete_id">
      <description summary="acknowledge object ID deletion">
	This event is used internally by the object ID management
	logic.  When a client deletes an object, the server will send
	this event to acknowledge that it has seen the delete request.
	When the client receive this event, it will know that it can
	safely reuse the object ID.
      </description>
      <arg name="id" type="uint" />
    </event>
  </interface>

  <interface name="wl_registry" version="1">
    <description summary="global registry object">
      The global registry object.  The server has a number of global
      objects that are available to all clients.  These objects
      typically represent an actual object in the server (for example,
      an input device) or they are singleton objects that provide
      extension functionality.

      When a client creates a registry object, the registry object
      will emit a global event for each global currently in the
      registry.  Globals come and go as a result of device or
      monitor hotplugs, reconfiguration or other events, and the
      registry will send out global and global_remove events to
      keep the client up to date with the changes.  To mark the end
      of the initial burst of events, the client can use the
      wl_display.sync request immediately after calling
      wl_display.get_registry.

      A client can bind to a global object by using the bind
      request.  This creates a client-side handle that lets the object
      emit events to the client and lets the client invoke requests on
      the object.
    </description>

    <request name="bind">
      <description summary="bind an object to the display">
	Binds a new, client-created object to the server using the
        specified name as the identifier.
      </description>
      <arg name="name" type="uint" summary="unique name for the object"/>
      <arg name="id" type="new_id"/>
    </request>

    <event name="global">
      <description summary="announce global object">
	Notify the client of global objects.

        The event notifies the client that a global object with
        the given name is now available, and it implements the
        given version of the given interface.
      </description>
      <arg name="name" type="uint"/>
      <arg name="interface" type="string"/>
      <arg name="version" type="uint"/>
    </event>

    <event name="global_remove">
      <description summary="announce removal of global object">
	Notify the client of removed global objects.

        This event notifies the client that the global identified
        by name is no longer available.  If the client bound to
        the global using the bind request, the client should now
        destroy that object.

	The object remains valid and requests to the object will be
	ignored until the client destroys it, to avoid races between
	the global going away and a client sending a request to it.
      </description>
      <arg name="name" type="uint"/>
    </event>
  </interface>

  <interface name="wl_callback" version="1">
    <description summary="callback object">
      Clients can handle the 'done' event to get notified when
      the related request is done.
    </description>
    <event name="done">
      <description summary="done event">
       Notify the client when the related request is done.
      </description>
      <arg name="serial" type="uint" summary="serial of the event"/>
    </event>
  </interface>

  <interface name="wl_compositor" version="2">
    <description summary="the compositor singleton">
      A compositor.  This object is a singleton global.  The
      compositor is in charge of combining the contents of multiple
      surfaces into one displayable output.
    </description>

    <request name="create_surface">
      <description summary="create new surface">
	Ask the compositor to create a new surface.
      </description>
      <arg name="id" type="new_id" interface="wl_surface"/>
    </request>

    <request name="create_region">
      <description summary="create new region">
	Ask the compositor to create a new region.
      </description>
      <arg name="id" type="new_id" interface="wl_region"/>
    </request>
  </interface>

  <interface name="wl_shm_pool" version="1">
    <description summary="a shared memory pool">
      The wl_shm_pool object encapsulates a piece of memory shared
      between the compositor and client.  Through the wl_shm_pool
      object, the client can allocate shared memory wl_buffer objects.
      All objects created through the same pool share the same
      underlying mapped memory. Reusing the mapped memory avoids the
      setup/teardown overhead and is useful when interactively resizing
      a surface or for many small buffers.
    </description>

    <request name="create_buffer">
      <description summary="create a buffer from the pool">
	Create a wl_buffer object from the pool.

	The buffer is created offset bytes into the pool and has
	width and height as specified.  The stride arguments specifies
	the number of bytes from beginning of one row to the beginning
	of the next.  The format is the pixel format of the buffer and
	must be one of those advertised through the wl_shm.format event.

	A buffer will keep a reference to the pool it was created from
	so it is valid to destroy the pool immediately after creating
	a buffer from it.
      </description>

      <arg name="id" type="new_id" interface="wl_buffer"/>
      <arg name="offset" type="int"/>
      <arg name="width" type="int"/>
      <arg name="height" type="int"/>
      <arg name="stride" type="int"/>
      <arg name="format" type="uint"/>
    </request>

    <request name="destroy" type="destructor">
      <description summary="destroy the pool">
	Destroy the shared memory pool.

	The mmapped memory will be released when all
	buffers that have been created from this pool
	are gone.
      </description>
    </request>

    <request name="resize">
      <description summary="change the size of the pool mapping">
	This request will cause the server to remap the backing memory
	for the pool from the file descriptor passed when the pool was
	created, but using the new size.
      </description>

      <arg name="size" type="int"/>
    </request>
  </interface>

  <interface name="wl_shm" version="1">
    <description summary="shared memory support">
      A global singleton object that provides support for shared
      memory.

      Clients can create wl_shm_pool objects using the create_pool
      request.

      At connection setup time, the wl_shm object emits one or more
      format events to inform clients about the valid pixel formats
      that can be used for buffers.
    </description>

    <enum name="error">
      <description summary="wl_shm error values">
	These errors can be emitted in response to wl_shm requests.
      </description>
      <entry name="invalid_format" value="0" summary="buffer format is not known"/>
      <entry name="invalid_stride" value="1" summary="invalid size or stride during pool or buffer creation"/>
      <entry name="invalid_fd" value="2" summary="mmapping the file descriptor failed"/>
    </enum>

    <enum name="format">
      <description summary="pixel formats">
	This describes the memory layout of an individual pixel.
      </description>
      <entry name="argb8888" value="0" summary="32-bit ARGB format"/>
      <entry name="xrgb8888" value="1" summary="32-bit RGB format"/>
    </enum>

    <request name="create_pool">
      <description summary="create a shm pool">
	Create a new wl_shm_pool object.

	The pool can be used to create shared memory based buffer
	objects.  The server will mmap size bytes of the passed file
        descriptor, to use as backing memory for the pool.
      </description>

      <arg name="id" type="new_id" interface="wl_shm_pool"/>
      <arg name="fd" type="fd"/>
      <arg name="size" type="int"/>
    </request>

    <event name="format">
      <description summary="pixel format description">
	Informs the client about a valid pixel format that
	can be used for buffers. Known formats include
	argb8888 and xrgb8888.
      </description>
      <arg name="format" type="uint"/>
    </event>
  </interface>

  <interface name="wl_buffer" version="1">
    <description summary="content for a wl_surface">
      A buffer provides the content for a wl_surface. Buffers are
      created through factory interfaces such as wl_drm, wl_shm or
      similar. It has a width and a height and can be attached to a
      wl_surface, but the mechanism by which a client provides and
      updates the contents is defined by the buffer factory interface.
    </description>

    <request name="destroy" type="destructor">
      <description summary="destroy a buffer">
	Destroy a buffer. If and how you need to release the backing
	storage is defined by the buffer factory interface.

	For possible side-effects to a surface, see wl_surface.attach.
      </description>
    </request>

    <event name="release">
      <description summary="compositor releases buffer">
	Sent when this wl_buffer is no longer used by the compositor.
	The client is now free to re-use or destroy this buffer and its
	backing storage.

	If a client receives a release event before the frame callback
	requested in the same wl_surface.commit that attaches this
	wl_buffer to a surface, then the client is immediately free to
	re-use the buffer and its backing storage, and does not need a
	second buffer for the next surface content update. Typically
	this is possible, when the compositor maintains a copy of the
	wl_surface contents, e.g. as a GL texture. This is an important
	optimization for GL(ES) compositors with wl_shm clients.
      </description>
    </event>
  </interface>


  <interface name="wl_data_offer" version="1">
    <description summary="offer to transfer data">
      A wl_data_offer represents a piece of data offered for transfer
      by another client (the source client).  It is used by the
      copy-and-paste and drag-and-drop mechanisms.  The offer
      describes the different mime types that the data can be
      converted to and provides the mechanism for transferring the
      data directly from the source client.
    </description>

    <request name="accept">
      <description summary="accept one of the offered mime types">
	Indicate that the client can accept the given mime type, or
	NULL for not accepted.

	Used for feedback during drag-and-drop.
      </description>

      <arg name="serial" type="uint"/>
      <arg name="mime_type" type="string" allow-null="true"/>
    </request>

    <request name="receive">
      <description summary="request that the data is transferred">
	To transfer the offered data, the client issues this request
	and indicates the mime type it wants to receive.  The transfer
	happens through the passed file descriptor (typically created
	with the pipe system call).  The source client writes the data
	in the mime type representation requested and then closes the
	file descriptor.

	The receiving client reads from the read end of the pipe until
	EOF and the closes its end, at which point the transfer is
	complete.
      </description>
      <arg name="mime_type" type="string"/>
      <arg name="fd" type="fd"/>
    </request>

    <request name="destroy" type="destructor">
      <description summary="destroy data offer">
	Destroy the data offer.
      </description>
    </request>

    <event name="offer">
      <description summary="advertise offered mime type">
	Sent immediately after creating the wl_data_offer object.  One
	event per offered mime type.
      </description>

      <arg name="mime_type" type="string"/>
    </event>
  </interface>

  <interface name="wl_data_source" version="1">
    <description summary="offer to transfer data">
      The wl_data_source object is the source side of a wl_data_offer.
      It is created by the source client in a data transfer and
      provides a way to describe the offered data and a way to respond
      to requests to transfer the data.
    </description>

    <request name="offer">
      <description summary="add an offered mime type">
	This request adds a mime type to the set of mime types
	advertised to targets.  Can be called several times to offer
	multiple types.
      </description>
      <arg name="mime_type" type="string"/>
    </request>

    <request name="destroy" type="destructor">
      <description summary="destroy the data source">
	Destroy the data source.
      </description>
    </request>

    <event name="target">
      <description summary="a target accepts an offered mime type">
	Sent when a target accepts pointer_focus or motion events.  If
	a target does not accept any of the offered types, type is NULL.

	Used for feedback during drag-and-drop.
      </description>

      <arg name="mime_type" type="string" allow-null="true"/>
    </event>

    <event name="send">
      <description summary="send the data">
	Request for data from the client.  Send the data as the
	specified mime type over the passed file descriptor, then
	close it.
      </description>

      <arg name="mime_type" type="string"/>
      <arg name="fd" type="fd"/>
    </event>

    <event name="cancelled">
      <description summary="selection was cancelled">
	This data source has been replaced by another data source.
	The client should clean up and destroy this data source.
      </description>
    </event>

  </interface>

  <interface name="wl_data_device" version="1">
    <description summary="data transfer device">
      There is one wl_data_device per seat which can be obtained
      from the global wl_data_device_manager singleton.

      A wl_data_device provides access to inter-client data transfer
      mechanisms such as copy-and-paste and drag-and-drop.
    </description>
    <request name="start_drag">
      <description summary="start drag-and-drop operation">
	This request asks the compositor to start a drag-and-drop
	operation on behalf of the client.

	The source argument is the data source that provides the data
	for the eventual data transfer. If source is NULL, enter, leave
	and motion events are sent only to the client that initiated the
	drag and the client is expected to handle the data passing
	internally.

	The origin surface is the surface where the drag originates and
	the client must have an active implicit grab that matches the
	serial.

	The icon surface is an optional (can be NULL) surface that
	provides an icon to be moved around with the cursor.  Initially,
	the top-left corner of the icon surface is placed at the cursor
	hotspot, but subsequent wl_surface.attach request can move the
	relative position. Attach requests must be confirmed with
	wl_surface.commit as usual.

	The current and pending input regions of the icon wl_surface are
	cleared, and wl_surface.set_input_region is ignored until the
	wl_surface is no longer used as the icon surface. When the use
	as an icon ends, the the current and pending input regions
	become undefined, and the wl_surface is unmapped.
      </description>
      <arg name="source" type="object" interface="wl_data_source" allow-null="true"/>
      <arg name="origin" type="object" interface="wl_surface"/>
      <arg name="icon" type="object" interface="wl_surface" allow-null="true"/>
      <arg name="serial" type="uint" summary="serial of the implicit grab on the origin"/>
    </request>

    <request name="set_selection">
      <description summary="copy data to the selection">
	This request asks the compositor to set the selection
	to the data from the source on behalf of the client.

	To unset the selection, set the source to NULL.
      </description>
      <arg name="source" type="object" interface="wl_data_source" allow-null="true"/>
      <arg name="serial" type="uint" summary="serial of the event that triggered this request"/>
    </request>

    <event name="data_offer">
      <description summary="introduce a new wl_data_offer">
	The data_offer event introduces a new wl_data_offer object,
	which will subsequently be used in either the
	data_device.enter event (for drag-and-drop) or the
	data_device.selection event (for selections).  Immediately
	following the data_device_data_offer event, the new data_offer
	object will send out data_offer.offer events to describe the
	mime types it offers.
      </description>

      <arg name="id" type="new_id" interface="wl_data_offer"/>
    </event>

    <event name="enter">
      <description summary="initiate drag-and-drop session">
	This event is sent when an active drag-and-drop pointer enters
	a surface owned by the client.  The position of the pointer at
	enter time is provided by the x an y arguments, in surface
	local coordinates.
      </description>

      <arg name="serial" type="uint"/>
      <arg name="surface" type="object" interface="wl_surface"/>
      <arg name="x" type="fixed"/>
      <arg name="y" type="fixed"/>
      <arg name="id" type="object" interface="wl_data_offer" allow-null="true"/>
    </event>

    <event name="leave">
      <description summary="end drag-and-drop session">
	This event is sent when the drag-and-drop pointer leaves the
	surface and the session ends.  The client must destroy the
	wl_data_offer introduced at enter time at this point.
      </description>
    </event>

    <event name="motion">
      <description summary="drag-and-drop session motion">
	This event is sent when the drag-and-drop pointer moves within
	the currently focused surface. The new position of the pointer
	is provided by the x an y arguments, in surface local
	coordinates.
      </description>
      <arg name="time" type="uint" summary="timestamp with millisecond granularity"/>
      <arg name="x" type="fixed"/>
      <arg name="y" type="fixed"/>
    </event>

    <event name="drop">
      <description summary="end drag-and-drag session successfully">
	The event is sent when a drag-and-drop operation is ended
	because the implicit grab is removed.
      </description>
    </event>

    <event name="selection">
      <description summary="advertise new selection">
	The selection event is sent out to notify the client of a new
	wl_data_offer for the selection for this device.  The
	data_device.data_offer and the data_offer.offer events are
	sent out immediately before this event to introduce the data
	offer object.  The selection event is sent to a client
	immediately before receiving keyboard focus and when a new
	selection is set while the client has keyboard focus.  The
	data_offer is valid until a new data_offer or NULL is received
	or until the client loses keyboard focus.
      </description>
      <arg name="id" type="object" interface="wl_data_offer" allow-null="true"/>
    </event>
  </interface>

  <interface name="wl_data_device_manager" version="1">
    <description summary="data transfer interface">
      The wl_data_device_manager is a a singleton global object that
      provides access to inter-client data transfer mechanisms such as
      copy-and-paste and drag-and-drop.  These mechanisms are tied to
      a wl_seat and this interface lets a client get a wl_data_device
      corresponding to a wl_seat.
    </description>

    <request name="create_data_source">
      <description summary="create a new data source">
        Create a new data source.
      </description>
      <arg name="id" type="new_id" interface="wl_data_source"/>
    </request>

    <request name="get_data_device">
      <description summary="create a new data device">
        Create a new data device for a given seat.
      </description>
      <arg name="id" type="new_id" interface="wl_data_device"/>
      <arg name="seat" type="object" interface="wl_seat"/>
    </request>
  </interface>

  <interface name="wl_shell" version="1">
    <description summary="create desktop-style surfaces">
      This interface is implemented by servers that provide
      desktop-style user interfaces.

      It allows clients to associate a wl_shell_surface with
      a basic surface.
    </description>

    <request name="get_shell_surface">
      <description summary="create a shell surface from a surface">
	Create a shell surface for an existing surface.

	Only one shell surface can be associated with a given surface.
      </description>
      <arg name="id" type="new_id" interface="wl_shell_surface"/>
      <arg name="surface" type="object" interface="wl_surface"/>
    </request>
  </interface>

  <interface name="wl_shell_surface" version="1">

    <description summary="desktop-style metadata interface">
      An interface that may be implemented by a wl_surface, for
      implementations that provide a desktop-style user interface.

      It provides requests to treat surfaces like toplevel, fullscreen
      or popup windows, move, resize or maximize them, associate
      metadata like title and class, etc.

      On the server side the object is automatically destroyed when
      the related wl_surface is destroyed.  On client side,
      wl_shell_surface_destroy() must be called before destroying
      the wl_surface object.
    </description>

    <request name="pong">
      <description summary="respond to a ping event">
	A client must respond to a ping event with a pong request or
	the client may be deemed unresponsive.
      </description>
      <arg name="serial" type="uint" summary="serial of the ping event"/>
    </request>

    <request name="move">
      <description summary="start an interactive move">
	Start a pointer-driven move of the surface.

	This request must be used in response to a button press event.
	The server may ignore move requests depending on the state of
	the surface (e.g. fullscreen or maximized).
      </description>
      <arg name="seat" type="object" interface="wl_seat" summary="the wl_seat whose pointer is used"/>
      <arg name="serial" type="uint" summary="serial of the implicit grab on the pointer"/>
    </request>

    <enum name="resize">
      <description summary="edge values for resizing">
	These values are used to indicate which edge of a surface
	is being dragged in a resize operation. The server may
	use this information to adapt its behavior, e.g. choose
	an appropriate cursor image.
      </description>
      <entry name="none" value="0"/>
      <entry name="top" value="1"/>
      <entry name="bottom" value="2"/>
      <entry name="left" value="4"/>
      <entry name="top_left" value="5"/>
      <entry name="bottom_left" value="6"/>
      <entry name="right" value="8"/>
      <entry name="top_right" value="9"/>
      <entry name="bottom_right" value="10"/>
    </enum>

    <request name="resize">
      <description summary="start an interactive resize">
	Start a pointer-driven resizing of the surface.

	This request must be used in response to a button press event.
	The server may ignore resize requests depending on the state of
	the surface (e.g. fullscreen or maximized).
      </description>
      <arg name="seat" type="object" interface="wl_seat" summary="the wl_seat whose pointer is used"/>
      <arg name="serial" type="uint" summary="serial of the implicit grab on the pointer"/>
      <arg name="edges" type="uint" summary="which edge or corner is being dragged"/>
    </request>

    <request name="set_toplevel">
      <description summary="make the surface a toplevel surface">
	Map the surface as a toplevel surface.

	A toplevel surface is not fullscreen, maximized or transient.
      </description>
    </request>

    <enum name="transient">
      <description summary="details of transient behaviour">
	These flags specify details of the expected behaviour
	of transient surfaces. Used in the set_transient request.
      </description>
      <entry name="inactive" value="0x1" summary="do not set keyboard focus"/>
    </enum>

    <request name="set_transient">
      <description summary="make the surface a transient surface">
	Map the surface relative to an existing surface.

	The x and y arguments specify the locations of the upper left
	corner of the surface relative to the upper left corner of the
	parent surface.

	The flags argument controls details of the transient behaviour.
      </description>

      <arg name="parent" type="object" interface="wl_surface"/>
      <arg name="x" type="int"/>
      <arg name="y" type="int"/>
      <arg name="flags" type="uint"/>
    </request>

    <enum name="fullscreen_method">
      <description summary="different method to set the surface fullscreen">
	Hints to indicate to the compositor how to deal with a conflict
	between the dimensions of the surface and the dimensions of the
	output. The compositor is free to ignore this parameter.
      </description>
      <entry name="default" value="0" summary="no preference, apply default policy"/>
      <entry name="scale" value="1" summary="scale, preserve the surface's aspect ratio and center on output"/>
      <entry name="driver" value="2" summary="switch output mode to the smallest mode that can fit the surface, add black borders to compensate size mismatch"/>
      <entry name="fill" value="3" summary="no scaling, center on output and add black borders to compensate size mismatch"/>
    </enum>

    <request name="set_fullscreen">
      <description summary="make the surface a fullscreen surface">
	Map the surface as a fullscreen surface.

	If an output parameter is given then the surface will be made
	fullscreen on that output. If the client does not specify the
	output then the compositor will apply its policy - usually
	choosing the output on which the surface has the biggest surface
	area.

	The client may specify a method to resolve a size conflict
	between the output size and the surface size - this is provided
	through the method parameter.

	The framerate parameter is used only when the method is set
	to "driver", to indicate the preferred framerate. A value of 0
	indicates that the app does not care about framerate.  The
	framerate is specified in mHz, that is framerate of 60000 is 60Hz.

	The compositor must reply to this request with a configure event
	with the dimensions for the output on which the surface will
	be made fullscreen.
      </description>
      <arg name="method" type="uint"/>
      <arg name="framerate" type="uint"/>
      <arg name="output" type="object" interface="wl_output" allow-null="true"/>
    </request>

    <request name="set_popup">
      <description summary="make the surface a popup surface">
	Map the surface as a popup.

	A popup surface is a transient surface with an added pointer
	grab.

	An existing implicit grab will be changed to owner-events mode,
	and the popup grab will continue after the implicit grab ends
	(i.e. releasing the mouse button does not cause the popup to
	be unmapped).

	The popup grab continues until the window is destroyed or a
	mouse button is pressed in any other clients window. A click
	in any of the clients surfaces is reported as normal, however,
	clicks in other clients surfaces will be discarded and trigger
	the callback.
      </description>

      <arg name="seat" type="object" interface="wl_seat" summary="the wl_seat whose pointer is used"/>
      <arg name="serial" type="uint" summary="serial of the implicit grab on the pointer"/>
      <arg name="parent" type="object" interface="wl_surface"/>
      <arg name="x" type="int"/>
      <arg name="y" type="int"/>
      <arg name="flags" type="uint"/>
    </request>

    <request name="set_maximized">
      <description summary="make the surface a maximized surface">
	Map the surface as a maximized surface.

	If an output parameter is given then the surface will be
	maximized on that output. If the client does not specify the
	output then the compositor will apply its policy - usually
	choosing the output on which the surface has the biggest surface
	area.

	The compositor will reply with a configure event telling
	the expected new surface size. The operation is completed
	on the next buffer attach to this surface.

	A maximized surface typically fills the entire output it is
	bound to, except for desktop element such as panels. This is
	the main difference between a maximized shell surface and a
	fullscreen shell surface.

	The details depend on the compositor implementation.
      </description>
      <arg name="output" type="object" interface="wl_output" allow-null="true"/>
    </request>

    <request name="set_title">
      <description summary="set surface title">
	Set a short title for the surface.

	This string may be used to identify the surface in a task bar,
	window list, or other user interface elements provided by the
	compositor.

	The string must be encoded in UTF-8.
      </description>
      <arg name="title" type="string"/>
    </request>

    <request name="set_class">
      <description summary="set surface class">
	Set a class for the surface.

	The surface class identifies the general class of applications
	to which the surface belongs. A common convention is to use
	the file name (full path if non-standard location) of the
	applications .desktop file as the class.
      </description>
      <arg name="class_" type="string"/>
    </request>

    <event name="ping">
      <description summary="ping client">
	Ping a client to check if it is receiving events and sending
	requests. A client is expected to reply with a pong request.
      </description>
      <arg name="serial" type="uint"/>
    </event>

    <event name="configure">
      <description summary="suggest resize">
	The configure event asks the client to resize its surface.

	The size is a hint, in the sense that the client is free to
	ignore it if it doesn't resize, pick a smaller size (to
	satisfy aspect ratio or resize in steps of NxM pixels).

	The edges parameter provides a hint about how the surface
	was resized. The client may use this information to decide
	how to adjust its content to the new size (e.g. a scrolling
	area might adjust its content position to leave the viewable
	content unmoved).

	The client is free to dismiss all but the last configure
	event it received.
      </description>

      <arg name="edges" type="uint"/>
      <arg name="width" type="int"/>
      <arg name="height" type="int"/>
    </event>

    <event name="popup_done">
      <description summary="popup interaction is done">
	The popup_done event is sent out when a popup grab is broken,
	that is, when the users clicks a surface that doesn't belong
	to the client owning the popup surface.
      </description>
    </event>
  </interface>

  <interface name="wl_surface" version="2">
    <description summary="an onscreen surface">
      A surface is a rectangular area that is displayed on the screen.
      It has a location, size and pixel contents.

      Surfaces are also used for some special purposes, e.g. as
      cursor images for pointers, drag icons, etc.
    </description>

    <request name="destroy" type="destructor">
      <description summary="delete surface">
	Deletes the surface and invalidates its object ID.
      </description>
    </request>

    <request name="attach">
      <description summary="set the surface contents">
	Set a buffer as the content of this surface.

	The x and y arguments specify the location of the new pending
	buffer's upper left corner, relative to the current buffer's
	upper left corner. In other words, the x and y, and the width
	and height of the wl_buffer together define in which directions
	the surface's size changes.

	Surface contents are double-buffered state, see wl_surface.commit.

	The initial surface contents are void; there is no content.
	wl_surface.attach assigns the given wl_buffer as the pending
	wl_buffer. wl_surface.commit makes the pending wl_buffer the new
	surface contents, and the size of the surface becomes the size of
	the wl_buffer, as described above. After commit, there is no
	pending buffer until the next attach.

	Committing a pending wl_buffer allows the compositor to read the
	pixels in the wl_buffer. The compositor may access the pixels at
	any time after the wl_surface.commit request. When the compositor
	will not access the pixels anymore, it will send the
	wl_buffer.release event. Only after receiving wl_buffer.release,
	the client may re-use the wl_buffer. A wl_buffer that has been
	attached and then replaced by another attach instead of committed
	will not receive a release event, and is not used by the
	compositor.

	Destroying the wl_buffer after wl_buffer.release does not change
	the surface contents. However, if the client destroys the
	wl_buffer before receiving wl_buffer.release, the surface
	contents become undefined immediately.

	Only if wl_surface.attach is sent with a NULL wl_buffer, the
	following wl_surface.commit will remove the surface content.
      </description>

      <arg name="buffer" type="object" interface="wl_buffer" allow-null="true"/>
      <arg name="x" type="int"/>
      <arg name="y" type="int"/>
    </request>

    <request name="damage">
      <description summary="mark part of the surface damaged">
	This request is used to describe the regions where the pending
	buffer is different from the current surface contents, and where
	the surface therefore needs to be repainted. The pending buffer
	must be set by wl_surface.attach before sending damage. The
	compositor ignores the parts of the damage that fall outside of
	the surface.

	Damage is double-buffered state, see wl_surface.commit.

	The initial value for pending damage is empty: no damage.
	wl_surface.damage adds pending damage: the new pending damage
	is the union of old pending damage and the given rectangle.

	wl_surface.commit assigns pending damage as the current damage,
	and clears pending damage. The server will clear the current
	damage as it repaints the surface.
      </description>

      <arg name="x" type="int"/>
      <arg name="y" type="int"/>
      <arg name="width" type="int"/>
      <arg name="height" type="int"/>
    </request>

    <request name="frame">
      <description summary="request repaint feedback">
	Request notification when the next frame is displayed. Useful
	for throttling redrawing operations, and driving animations.
	The frame request will take effect on the next wl_surface.commit.
	The notification will only be posted for one frame unless
	requested again.

	A server should avoid signalling the frame callbacks if the
	surface is not visible in any way, e.g. the surface is off-screen,
	or completely obscured by other opaque surfaces.

	A client can request a frame callback even without an attach,
	damage, or any other state changes. wl_surface.commit triggers a
	display update, so the callback event will arrive after the next
	output refresh where the surface is visible.
      </description>

      <arg name="callback" type="new_id" interface="wl_callback"/>
    </request>

    <request name="set_opaque_region">
      <description summary="set opaque region">
	This request sets the region of the surface that contains
	opaque content.

	The opaque region is an optimization hint for the compositor
	that lets it optimize out redrawing of content behind opaque
	regions.  Setting an opaque region is not required for correct
	behaviour, but marking transparent content as opaque will result
	in repaint artifacts.

	The compositor ignores the parts of the opaque region that fall
	outside of the surface.

	Opaque region is double-buffered state, see wl_surface.commit.

	wl_surface.set_opaque_region changes the pending opaque region.
	wl_surface.commit copies the pending region to the current region.
	Otherwise, the pending and current regions are never changed.

	The initial value for opaque region is empty. Setting the pending
	opaque region has copy semantics, and the wl_region object can be
	destroyed immediately. A NULL wl_region causes the pending opaque
	region to be set to empty.
      </description>

      <arg name="region" type="object" interface="wl_region" allow-null="true"/>
    </request>

    <request name="set_input_region">
      <description summary="set input region">
	This request sets the region of the surface that can receive
	pointer and touch events.

	Input events happening outside of this region will try the next
	surface in the server surface stack. The compositor ignores the
	parts of the input region that fall outside of the surface.

	Input region is double-buffered state, see wl_surface.commit.

	wl_surface.set_input_region changes the pending input region.
	wl_surface.commit copies the pending region to the current region.
	Otherwise the pending and current regions are never changed,
	except cursor and icon surfaces are special cases, see
	wl_pointer.set_cursor and wl_data_device.start_drag.

	The initial value for input region is infinite. That means the
	whole surface will accept input. Setting the pending input region
	has copy semantics, and the wl_region object can be destroyed
	immediately. A NULL wl_region causes the input region to be set
	to infinite.
      </description>

      <arg name="region" type="object" interface="wl_region" allow-null="true"/>
    </request>

    <request name="commit">
      <description summary="commit pending surface state">
	Surface state (input, opaque, and damage regions, attached buffers,
	etc.) is double-buffered. Protocol requests modify the pending
	state, as opposed to current state in use by the compositor. Commit
	request atomically applies all pending state, replacing the current
	state. After commit, the new pending state is as documented for each
	related request.

	On commit, a pending wl_buffer is applied first, all other state
	second. This means that all coordinates in double-buffered state are
	relative to the new wl_buffer coming into use, except for
	wl_surface.attach itself. If there is no pending wl_buffer, the
	coordinates are relative to the current surface contents.

	All requests that need a commit to become effective are documented
	to affect double-buffered state.

	Other interfaces may add further double-buffered surface state.
      </description>
    </request>

    <event name="enter">
      <description summary="surface enters an output">
	This is emitted whenever a surface's creation, movement, or resizing
	results in some part of it being within the scanout region of an
	output.

	Note that a surface may be overlapping with zero or more outputs.
      </description>
      <arg name="output" type="object" interface="wl_output"/>
    </event>

    <event name="leave">
      <description summary="surface leaves an output">
	This is emitted whenever a surface's creation, movement, or resizing
	results in it no longer having any part of it within the scanout region
	of an output.
      </description>
      <arg name="output" type="object" interface="wl_output"/>
    </event>

    <!-- Version 2 additions -->

    <request name="set_buffer_transform" since="2">
      <description summary="sets the buffer transformation">
	This request sets an optional transformation on how the compositor
	interprets the contents of the buffer attached to the surface. The
	accepted values for the transform parameter are the values for
	wl_output.transform.

	Buffer transform is double-buffered state, see wl_surface.commit.

	A newly created surface has its buffer transformation set to normal.

	The purpose of this request is to allow clients to render content
	according to the output transform, thus permiting the compositor to
	use certain optimizations even if the display is rotated. Using
	hardware overlays and scanning out a client buffer for fullscreen
	surfaces are examples of such optmizations. Those optimizations are
	highly dependent on the compositor implementation, so the use of this
	request should be considered on a case-by-case basis.

	Note that if the transform value includes 90 or 270 degree rotation,
	the width of the buffer will become the surface height and the height
	of the buffer will become the surface width.
      </description>
      <arg name="transform" type="int"/>
    </request>
   </interface>

  <interface name="wl_seat" version="1">
    <description summary="group of input devices">
      A seat is a group of keyboards, pointer (mice, for example) and
      touch devices. This object is published as a global during
      start up, or when such a device is hot plugged.  A seat typically
      has a pointer and maintains a keyboard focus and a pointer focus.
    </description>

    <enum name="capability">
      <description summary="seat capability bitmask">
        This is a bitmask of capabilities this seat has; if a member is
        set, then it is present on the seat.
      </description>
      <entry name="pointer" value="1" summary="The seat has pointer devices"/>
      <entry name="keyboard" value="2" summary="The seat has one or more keyboards"/>
      <entry name="touch" value="4" summary="The seat has touch devices"/>
    </enum>

    <event name="capabilities">
      <description summary="seat capabilities changed">
        This is emitted whenever a seat gains or loses the pointer,
	keyboard or touch capabilities.  The argument is a capability
	enum containing the complete set of capabilities this seat has.
      </description>
      <arg name="capabilities" type="uint"/>
    </event>

    <request name="get_pointer">
      <description summary="return pointer object">
        The ID provided will be initialized to the wl_pointer interface
	for this seat.

        This request only takes effect if the seat has the pointer
        capability.
      </description>
      <arg name="id" type="new_id" interface="wl_pointer"/>
    </request>

    <request name="get_keyboard">
      <description summary="return keyboard object">
        The ID provided will be initialized to the wl_keyboard interface
	for this seat.

        This request only takes effect if the seat has the keyboard
        capability.
      </description>
      <arg name="id" type="new_id" interface="wl_keyboard"/>
    </request>

    <request name="get_touch">
      <description summary="return touch object">
        The ID provided will be initialized to the wl_touch interface
	for this seat.

        This request only takes effect if the seat has the touch
        capability.
      </description>
      <arg name="id" type="new_id" interface="wl_touch"/>
    </request>
  </interface>

  <interface name="wl_pointer" version="1">
    <description summary="pointer input device">
      The wl_pointer interface represents one or more input devices,
      such as mice, which control the pointer location and pointer_focus
      of a seat.

      The wl_pointer interface generates motion, enter and leave
      events for the surfaces that the pointer is located over,
      and button and axis events for button presses, button releases
      and scrolling.
    </description>

    <request name="set_cursor">
      <description summary="set the pointer surface">
	Set the pointer surface, i.e., the surface that contains the
	pointer image (cursor). This request only takes effect if the pointer
	focus for this device is one of the requesting client's surfaces
	or the surface parameter is the current pointer surface. If
	there was a previous surface set with this request it is
	replaced. If surface is NULL, the pointer image is hidden.

	The parameters hotspot_x and hotspot_y define the position of
	the pointer surface relative to the pointer location. Its
	top-left corner is always at (x, y) - (hotspot_x, hotspot_y),
	where (x, y) are the coordinates of the pointer location.

	On surface.attach requests to the pointer surface, hotspot_x
	and hotspot_y are decremented by the x and y parameters
	passed to the request. Attach must be confirmed by
	wl_surface.commit as usual.

	The hotspot can also be updated by passing the currently set
	pointer surface to this request with new values for hotspot_x
	and hotspot_y.

	The current and pending input regions of the wl_surface are
	cleared, and wl_surface.set_input_region is ignored until the
	wl_surface is no longer used as the cursor. When the use as a
	cursor ends, the current and pending input regions become
	undefined, and the wl_surface is unmapped.
      </description>

      <arg name="serial" type="uint" summary="serial of the enter event"/>
      <arg name="surface" type="object" interface="wl_surface" allow-null="true"/>
      <arg name="hotspot_x" type="fixed" summary="x coordinate in surface-relative coordinates"/>
      <arg name="hotspot_y" type="fixed" summary="y coordinate in surface-relative coordinates"/>
    </request>

    <event name="enter">
      <description summary="enter event">
	Notification that this seat's pointer is focused on a certain
	surface.

	When an seat's focus enters a surface, the pointer image
	is undefined and a client should respond to this event by setting
	an appropriate pointer image with the set_cursor request.
      </description>

      <arg name="serial" type="uint"/>
      <arg name="surface" type="object" interface="wl_surface"/>
      <arg name="surface_x" type="fixed" summary="x coordinate in surface-relative coordinates"/>
      <arg name="surface_y" type="fixed" summary="y coordinate in surface-relative coordinates"/>
    </event>

    <event name="leave">
      <description summary="leave event">
	Notification that this seat's pointer is no longer focused on
	a certain surface.

	The leave notification is sent before the enter notification
	for the new focus.
      </description>
      <arg name="serial" type="uint"/>
      <arg name="surface" type="object" interface="wl_surface"/>
    </event>

    <event name="motion">
      <description summary="pointer motion event">
	Notification of pointer location change. The arguments
	surface_x and surface_y are the location relative to the
	focused surface.
      </description>

      <arg name="time" type="uint" summary="timestamp with millisecond granularity"/>
      <arg name="surface_x" type="fixed" summary="x coordinate in surface-relative coordinates"/>
      <arg name="surface_y" type="fixed" summary="y coordinate in surface-relative coordinates"/>
    </event>

    <enum name="button_state">
      <description summary="physical button state">
        Describes the physical state of a button which provoked the button
	event.
      </description>
      <entry name="released" value="0" summary="The button is not pressed"/>
      <entry name="pressed" value="1" summary="The button is pressed"/>
    </enum>

    <event name="button">
      <description summary="pointer button event">
	Mouse button click and release notifications.

	The location of the click is given by the last motion or
	enter event.
        The time argument is a timestamp with millisecond
        granularity, with an undefined base.
      </description>

      <arg name="serial" type="uint"/>
      <arg name="time" type="uint" summary="timestamp with millisecond granularity"/>
      <arg name="button" type="uint"/>
      <arg name="state" type="uint"/>
    </event>

    <enum name="axis">
      <description summary="axis types">
	Describes the axis types of scroll events.
      </description>
      <entry name="vertical_scroll" value="0"/>
      <entry name="horizontal_scroll" value="1"/>
    </enum>

    <event name="axis">
      <description summary="axis event">
	Scroll and other axis notifications.

	For scroll events (vertical and horizontal scroll axes), the
	value parameter is the length of a vector along the specified
	axis in a coordinate space identical to those of motion events,
	representing a relative movement along the specified axis.

	For devices that support movements non-parallel to axes multiple
	axis events will be emitted.

	When applicable, for example for touch pads, the server can
	choose to emit scroll events where the motion vector is
	equivalent to a motion event vector.

	When applicable, clients can transform its view relative to the
	scroll distance.
      </description>

      <arg name="time" type="uint" summary="timestamp with millisecond granularity"/>
      <arg name="axis" type="uint"/>
      <arg name="value" type="fixed"/>
    </event>
  </interface>

  <interface name="wl_keyboard" version="1">
    <description summary="keyboard input device">
      The wl_keyboard interface represents one or more keyboards
      associated with a seat.
    </description>

    <enum name="keymap_format">
      <description summary="keyboard mapping format">
	This specifies the format of the keymap provided to the
	client with the wl_keyboard.keymap event.
      </description>
      <entry name="xkb_v1" value="1" summary="libxkbcommon compatible"/>
    </enum>

    <event name="keymap">
      <description summary="keyboard mapping">
	This event provides a file descriptor to the client which can be
	memory-mapped to provide a keyboard mapping description.
      </description>
      <arg name="format" type="uint"/>
      <arg name="fd" type="fd"/>
      <arg name="size" type="uint"/>
    </event>

    <event name="enter">
      <description summary="enter event">
	Notification that this seat's keyboard focus is on a certain
	surface.
      </description>
      <arg name="serial" type="uint"/>
      <arg name="surface" type="object" interface="wl_surface"/>
      <arg name="keys" type="array" summary="the currently pressed keys"/>
    </event>

    <event name="leave">
      <description summary="leave event">
	Notification that this seat's keyboard focus is no longer on
	a certain surface.

	The leave notification is sent before the enter notification
	for the new focus.
      </description>
      <arg name="serial" type="uint"/>
      <arg name="surface" type="object" interface="wl_surface"/>
    </event>

    <enum name="key_state">
      <description summary="physical key state">
	Describes the physical state of a key which provoked the key event.
      </description>
      <entry name="released" value="0" summary="key is not pressed"/>
      <entry name="pressed" value="1" summary="key is pressed"/>
    </enum>

    <event name="key">
      <description summary="key event">
	A key was pressed or released.
        The time argument is a timestamp with millisecond
        granularity, with an undefined base.
      </description>

      <arg name="serial" type="uint"/>
      <arg name="time" type="uint" summary="timestamp with millisecond granularity"/>
      <arg name="key" type="uint"/>
      <arg name="state" type="uint"/>
    </event>

    <event name="modifiers">
      <description summary="modifier and group state">
	Notifies clients that the modifier and/or group state has
	changed, and it should update its local state.
      </description>

      <arg name="serial" type="uint"/>
      <arg name="mods_depressed" type="uint"/>
      <arg name="mods_latched" type="uint"/>
      <arg name="mods_locked" type="uint"/>
      <arg name="group" type="uint"/>
    </event>
  </interface>

  <interface name="wl_touch" version="1">
    <description summary="touchscreen input device">
      The wl_touch interface represents a touchscreen
      associated with a seat.

      Touch interactions can consist of one or more contacts.
      For each contact, a series of events is generated, starting
      with a down event, followed by one or more motion events,
      and ended with an up event. Events relating to the same
      contact point can be identified by the ID of the sequence.
    </description>

    <event name="down">
      <description summary="touch down event">
	A new touch point has appeared on the surface. This touch point is
	assigned a unique @id. Future events from this touchpoint reference
	this ID. The ID ceases to be valid after a touch up event and may be
	re-used in the future.
      </description>
      <arg name="serial" type="uint"/>
      <arg name="time" type="uint" summary="timestamp with millisecond granularity"/>
      <arg name="surface" type="object" interface="wl_surface"/>
      <arg name="id" type="int" summary="the unique ID of this touch point"/>
      <arg name="x" type="fixed" summary="x coordinate in surface-relative coordinates"/>
      <arg name="y" type="fixed" summary="y coordinate in surface-relative coordinates"/>
    </event>

    <event name="up">
      <description summary="end of a touch event sequence">
	The touch point has disappeared. No further events will be sent for
	this touchpoint and the touch point's ID is released and may be
	re-used in a future touch down event.
      </description>
      <arg name="serial" type="uint"/>
      <arg name="time" type="uint" summary="timestamp with millisecond granularity"/>
      <arg name="id" type="int" summary="the unique ID of this touch point"/>
    </event>

    <event name="motion">
      <description summary="end of a touch event sequence">
	A touchpoint has changed coordinates.
      </description>
      <arg name="time" type="uint" summary="timestamp with millisecond granularity"/>
      <arg name="id" type="int" summary="the unique ID of this touch point"/>
      <arg name="x" type="fixed" summary="x coordinate in surface-relative coordinates"/>
      <arg name="y" type="fixed" summary="y coordinate in surface-relative coordinates"/>
    </event>

    <event name="frame">
      <description summary="end of touch frame event">
	Indicates the end of a contact point list.
      </description>
    </event>

    <event name="cancel">
      <description summary="touch session cancelled">
	Sent if the compositor decides the touch stream is a global
	gesture. No further events are sent to the clients from that
	particular gesture. Touch cancellation applies to all touch points
	currently active on this client's surface. The client is
	responsible for finalizing the touch points, future touch points on
	this surface may re-use the touch point ID.
      </description>
    </event>
  </interface>

  <interface name="wl_output" version="1">
    <description summary="compositor output region">
      An output describes part of the compositor geometry.  The
      compositor works in the 'compositor coordinate system' and an
      output corresponds to rectangular area in that space that is
      actually visible.  This typically corresponds to a monitor that
      displays part of the compositor space.  This object is published
      as global during start up, or when a monitor is hotplugged.
    </description>

    <enum name="subpixel">
      <description summary="subpixel geometry information">
	This enumeration describes how the physical
	pixels on an output are layed out.
      </description>
      <entry name="unknown" value="0"/>
      <entry name="none" value="1"/>
      <entry name="horizontal_rgb" value="2"/>
      <entry name="horizontal_bgr" value="3"/>
      <entry name="vertical_rgb" value="4"/>
      <entry name="vertical_bgr" value="5"/>
    </enum>

    <enum name="transform">
      <description summary="transform from framebuffer to output">
	This describes the transform that a compositor will apply to a
	surface to compensate for the rotation or mirroring of an
	output device.

	The flipped values correspond to an initial flip around a
	vertical axis followed by rotation.

	The purpose is mainly to allow clients render accordingly and
	tell the compositor, so that for fullscreen surfaces, the
	compositor will still be able to scan out directly from client
	surfaces.
      </description>

      <entry name="normal" value="0"/>
      <entry name="90" value="1"/>
      <entry name="180" value="2"/>
      <entry name="270" value="3"/>
      <entry name="flipped" value="4"/>
      <entry name="flipped_90" value="5"/>
      <entry name="flipped_180" value="6"/>
      <entry name="flipped_270" value="7"/>
    </enum>

    <event name="geometry">
      <description summary="properties of the output">
	The geometry event describes geometric properties of the output.
	The event is sent when binding to the output object and whenever
	any of the properties change.
      </description>
      <arg name="x" type="int"
	   summary="x position within the global compositor space"/>
      <arg name="y" type="int"
	   summary="y position within the global compositor space"/>
      <arg name="physical_width" type="int"
	   summary="width in millimeters of the output"/>
      <arg name="physical_height" type="int"
	   summary="height in millimeters of the output"/>
      <arg name="subpixel" type="int"
	   summary="subpixel orientation of the output"/>
      <arg name="make" type="string"
	   summary="textual description of the manufacturer"/>
      <arg name="model" type="string"
	   summary="textual description of the model"/>
      <arg name="transform" type="int"
	   summary="transform that maps framebuffer to output"/>
    </event>

    <enum name="mode">
      <description summary="mode information">
	These flags describe properties of an output mode.
	They are used in the flags bitfield of the mode event.
      </description>
      <entry name="current" value="0x1"
	     summary="indicates this is the current mode"/>
      <entry name="preferred" value="0x2"
	     summary="indicates this is the preferred mode"/>
    </enum>

    <event name="mode">
      <description summary="advertise available modes for the output">
	The mode event describes an available mode for the output.

	The event is sent when binding to the output object and there
	will always be one mode, the current mode.  The event is sent
	again if an output changes mode, for the mode that is now
	current.  In other words, the current mode is always the last
	mode that was received with the current flag set.
      </description>
      <arg name="flags" type="uint" summary="bitfield of mode flags"/>
      <arg name="width" type="int" summary="width of the mode in pixels"/>
      <arg name="height" type="int" summary="height of the mode in pixels"/>
      <arg name="refresh" type="int" summary="vertical refresh rate in mHz"/>
    </event>
  </interface>

  <interface name="wl_region" version="1">
    <description summary="region interface">
      A region object describes an area.

      Region objects are used to describe the opaque and input
      regions of a surface.
    </description>

    <request name="destroy" type="destructor">
      <description summary="destroy region">
	Destroy the region.  This will invalidate the object ID.
      </description>
    </request>

    <request name="add">
      <description summary="add rectangle to region">
	Add the specified rectangle to the region.
      </description>

      <arg name="x" type="int"/>
      <arg name="y" type="int"/>
      <arg name="width" type="int"/>
      <arg name="height" type="int"/>
    </request>

    <request name="subtract">
      <description summary="subtract rectangle from region">
	Subtract the specified rectangle from the region.
      </description>

      <arg name="x" type="int"/>
      <arg name="y" type="int"/>
      <arg name="width" type="int"/>
      <arg name="height" type="int"/>
    </request>

  </interface>

</protocol>