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

<protocol name="wayland">

<copyright>

Copyright © 2008-2011 Kristian Høgsberg

Copyright © 2010-2011 Intel Corporation

Copyright © 2012-2013 Collabora, Ltd.

Permission is hereby granted, free of charge, to any person

obtaining a copy of this software and associated documentation files

(the "Software"), to deal in the Software without restriction,

including without limitation the rights to use, copy, modify, merge,

publish, distribute, sublicense, and/or sell copies of the Software,

and to permit persons to whom the Software is furnished to do so,

subject to the following conditions:

The above copyright notice and this permission notice (including the

next paragraph) shall be included in all copies or substantial

portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,

EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF

MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND

NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS

BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN

ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN

CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE

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

be used as a barrier to ensure all previous requests and the

resulting events have been handled.

The object returned by this request will be destroyed by the

compositor after the callback is fired and as such the client must not

attempt to use it after that point.

The callback_data passed in the callback is the event serial.

</description>

<arg name="callback" type="new_id" interface="wl_callback"

summary="callback object for the sync request"/>

</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="registry" type="new_id" interface="wl_registry"

summary="global registry object"/>

</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 a brief description

of the error, for (debugging) convenience.

</description>

<arg name="object_id" type="object" summary="object where the error occurred"/>

<arg name="code" type="uint" summary="error code"/>

<arg name="message" type="string" summary="error description"/>

</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 receives this event, it will know that it can

safely reuse the object ID.

</description>

<arg name="id" type="uint" summary="deleted object ID"/>

</event>

</interface>

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

<description summary="global registry object">

The singleton 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 numeric name of the object"/>

<arg name="id" type="new_id" summary="bounded object"/>

</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" summary="numeric name of the global object"/>

<arg name="interface" type="string" summary="interface implemented by the object"/>

<arg name="version" type="uint" summary="interface version"/>

</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" summary="numeric name of the global object"/>

</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="callback_data" type="uint" summary="request-specific data for the callback"/>

</event>

</interface>

<interface name="wl_compositor" version="4">

<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" summary="the new 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" summary="the new 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 argument specifies

the number of bytes from the 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" summary="buffer to create"/>

<arg name="offset" type="int" summary="buffer byte offset within the pool"/>

<arg name="width" type="int" summary="buffer width, in pixels"/>

<arg name="height" type="int" summary="buffer height, in pixels"/>

<arg name="stride" type="int" summary="number of bytes from the beginning of one row to the beginning of the next row"/>

<arg name="format" type="uint" enum="wl_shm.format" summary="buffer pixel format"/>

</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. This request can only be

used to make the pool bigger.

</description>

<arg name="size" type="int" summary="new size of the pool, in bytes"/>

</request>

</interface>

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

<description summary="shared memory support">

A singleton global 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.

All renderers should support argb8888 and xrgb8888 but any other

formats are optional and may not be supported by the particular

renderer in use.

The drm format codes match the macros defined in drm_fourcc.h.

The formats actually supported by the compositor will be

reported by the format event.

</description>

<entry name="argb8888" value="0" summary="32-bit ARGB format, [31:0] A:R:G:B 8:8:8:8 little endian"/>

<entry name="xrgb8888" value="1" summary="32-bit RGB format, [31:0] x:R:G:B 8:8:8:8 little endian"/>

<entry name="c8" value="0x20203843" summary="8-bit color index format, [7:0] C"/>

<entry name="rgb332" value="0x38424752" summary="8-bit RGB format, [7:0] R:G:B 3:3:2"/>

<entry name="bgr233" value="0x38524742" summary="8-bit BGR format, [7:0] B:G:R 2:3:3"/>

<entry name="xrgb4444" value="0x32315258" summary="16-bit xRGB format, [15:0] x:R:G:B 4:4:4:4 little endian"/>

<entry name="xbgr4444" value="0x32314258" summary="16-bit xBGR format, [15:0] x:B:G:R 4:4:4:4 little endian"/>

<entry name="rgbx4444" value="0x32315852" summary="16-bit RGBx format, [15:0] R:G:B:x 4:4:4:4 little endian"/>

<entry name="bgrx4444" value="0x32315842" summary="16-bit BGRx format, [15:0] B:G:R:x 4:4:4:4 little endian"/>

<entry name="argb4444" value="0x32315241" summary="16-bit ARGB format, [15:0] A:R:G:B 4:4:4:4 little endian"/>

<entry name="abgr4444" value="0x32314241" summary="16-bit ABGR format, [15:0] A:B:G:R 4:4:4:4 little endian"/>

<entry name="rgba4444" value="0x32314152" summary="16-bit RBGA format, [15:0] R:G:B:A 4:4:4:4 little endian"/>

<entry name="bgra4444" value="0x32314142" summary="16-bit BGRA format, [15:0] B:G:R:A 4:4:4:4 little endian"/>

<entry name="xrgb1555" value="0x35315258" summary="16-bit xRGB format, [15:0] x:R:G:B 1:5:5:5 little endian"/>

<entry name="xbgr1555" value="0x35314258" summary="16-bit xBGR 1555 format, [15:0] x:B:G:R 1:5:5:5 little endian"/>

<entry name="rgbx5551" value="0x35315852" summary="16-bit RGBx 5551 format, [15:0] R:G:B:x 5:5:5:1 little endian"/>

<entry name="bgrx5551" value="0x35315842" summary="16-bit BGRx 5551 format, [15:0] B:G:R:x 5:5:5:1 little endian"/>

<entry name="argb1555" value="0x35315241" summary="16-bit ARGB 1555 format, [15:0] A:R:G:B 1:5:5:5 little endian"/>

<entry name="abgr1555" value="0x35314241" summary="16-bit ABGR 1555 format, [15:0] A:B:G:R 1:5:5:5 little endian"/>

<entry name="rgba5551" value="0x35314152" summary="16-bit RGBA 5551 format, [15:0] R:G:B:A 5:5:5:1 little endian"/>

<entry name="bgra5551" value="0x35314142" summary="16-bit BGRA 5551 format, [15:0] B:G:R:A 5:5:5:1 little endian"/>

<entry name="rgb565" value="0x36314752" summary="16-bit RGB 565 format, [15:0] R:G:B 5:6:5 little endian"/>

<entry name="bgr565" value="0x36314742" summary="16-bit BGR 565 format, [15:0] B:G:R 5:6:5 little endian"/>

<entry name="rgb888" value="0x34324752" summary="24-bit RGB format, [23:0] R:G:B little endian"/>

<entry name="bgr888" value="0x34324742" summary="24-bit BGR format, [23:0] B:G:R little endian"/>

<entry name="xbgr8888" value="0x34324258" summary="32-bit xBGR format, [31:0] x:B:G:R 8:8:8:8 little endian"/>

<entry name="rgbx8888" value="0x34325852" summary="32-bit RGBx format, [31:0] R:G:B:x 8:8:8:8 little endian"/>

<entry name="bgrx8888" value="0x34325842" summary="32-bit BGRx format, [31:0] B:G:R:x 8:8:8:8 little endian"/>

<entry name="abgr8888" value="0x34324241" summary="32-bit ABGR format, [31:0] A:B:G:R 8:8:8:8 little endian"/>

<entry name="rgba8888" value="0x34324152" summary="32-bit RGBA format, [31:0] R:G:B:A 8:8:8:8 little endian"/>

<entry name="bgra8888" value="0x34324142" summary="32-bit BGRA format, [31:0] B:G:R:A 8:8:8:8 little endian"/>

<entry name="xrgb2101010" value="0x30335258" summary="32-bit xRGB format, [31:0] x:R:G:B 2:10:10:10 little endian"/>

<entry name="xbgr2101010" value="0x30334258" summary="32-bit xBGR format, [31:0] x:B:G:R 2:10:10:10 little endian"/>

<entry name="rgbx1010102" value="0x30335852" summary="32-bit RGBx format, [31:0] R:G:B:x 10:10:10:2 little endian"/>

<entry name="bgrx1010102" value="0x30335842" summary="32-bit BGRx format, [31:0] B:G:R:x 10:10:10:2 little endian"/>

<entry name="argb2101010" value="0x30335241" summary="32-bit ARGB format, [31:0] A:R:G:B 2:10:10:10 little endian"/>

<entry name="abgr2101010" value="0x30334241" summary="32-bit ABGR format, [31:0] A:B:G:R 2:10:10:10 little endian"/>

<entry name="rgba1010102" value="0x30334152" summary="32-bit RGBA format, [31:0] R:G:B:A 10:10:10:2 little endian"/>

<entry name="bgra1010102" value="0x30334142" summary="32-bit BGRA format, [31:0] B:G:R:A 10:10:10:2 little endian"/>

<entry name="yuyv" value="0x56595559" summary="packed YCbCr format, [31:0] Cr0:Y1:Cb0:Y0 8:8:8:8 little endian"/>

<entry name="yvyu" value="0x55595659" summary="packed YCbCr format, [31:0] Cb0:Y1:Cr0:Y0 8:8:8:8 little endian"/>

<entry name="uyvy" value="0x59565955" summary="packed YCbCr format, [31:0] Y1:Cr0:Y0:Cb0 8:8:8:8 little endian"/>

<entry name="vyuy" value="0x59555956" summary="packed YCbCr format, [31:0] Y1:Cb0:Y0:Cr0 8:8:8:8 little endian"/>

<entry name="ayuv" value="0x56555941" summary="packed AYCbCr format, [31:0] A:Y:Cb:Cr 8:8:8:8 little endian"/>

<entry name="nv12" value="0x3231564e" summary="2 plane YCbCr Cr:Cb format, 2x2 subsampled Cr:Cb plane"/>

<entry name="nv21" value="0x3132564e" summary="2 plane YCbCr Cb:Cr format, 2x2 subsampled Cb:Cr plane"/>

<entry name="nv16" value="0x3631564e" summary="2 plane YCbCr Cr:Cb format, 2x1 subsampled Cr:Cb plane"/>

<entry name="nv61" value="0x3136564e" summary="2 plane YCbCr Cb:Cr format, 2x1 subsampled Cb:Cr plane"/>

<entry name="yuv410" value="0x39565559" summary="3 plane YCbCr format, 4x4 subsampled Cb (1) and Cr (2) planes"/>

<entry name="yvu410" value="0x39555659" summary="3 plane YCbCr format, 4x4 subsampled Cr (1) and Cb (2) planes"/>

<entry name="yuv411" value="0x31315559" summary="3 plane YCbCr format, 4x1 subsampled Cb (1) and Cr (2) planes"/>

<entry name="yvu411" value="0x31315659" summary="3 plane YCbCr format, 4x1 subsampled Cr (1) and Cb (2) planes"/>

<entry name="yuv420" value="0x32315559" summary="3 plane YCbCr format, 2x2 subsampled Cb (1) and Cr (2) planes"/>

<entry name="yvu420" value="0x32315659" summary="3 plane YCbCr format, 2x2 subsampled Cr (1) and Cb (2) planes"/>

<entry name="yuv422" value="0x36315559" summary="3 plane YCbCr format, 2x1 subsampled Cb (1) and Cr (2) planes"/>

<entry name="yvu422" value="0x36315659" summary="3 plane YCbCr format, 2x1 subsampled Cr (1) and Cb (2) planes"/>

<entry name="yuv444" value="0x34325559" summary="3 plane YCbCr format, non-subsampled Cb (1) and Cr (2) planes"/>

<entry name="yvu444" value="0x34325659" summary="3 plane YCbCr format, non-subsampled Cr (1) and Cb (2) planes"/>

</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" summary="pool to create"/>

<arg name="fd" type="fd" summary="file descriptor for the pool"/>

<arg name="size" type="int" summary="pool size, in bytes"/>

</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" enum="format" summary="buffer pixel format"/>

</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 reuse 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

reuse 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="3">

<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>

<enum name="error">

<entry name="invalid_finish" value="0"

summary="finish request was called untimely"/>

<entry name="invalid_action_mask" value="1"

summary="action mask contains invalid values"/>

<entry name="invalid_action" value="2"

summary="action argument has an invalid value"/>

<entry name="invalid_offer" value="3"

summary="offer doesn't accept this request"/>

</enum>

<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.

For objects of version 2 or older, this request is used by the

client to give feedback whether the client can receive the given

mime type, or NULL if none is accepted; the feedback does not

determine whether the drag-and-drop operation succeeds or not.

For objects of version 3 or newer, this request determines the

final result of the drag-and-drop operation. If the end result

is that no mime types were accepted, the drag-and-drop operation

will be cancelled and the corresponding drag source will receive

wl_data_source.cancelled. Clients may still use this event in

conjunction with wl_data_source.action for feedback.

</description>

<arg name="serial" type="uint" summary="serial number of the accept request"/>

<arg name="mime_type" type="string" allow-null="true" summary="mime type accepted by the client"/>

</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 then closes its end, at which point the transfer is

complete.

This request may happen multiple times for different mime types,

both before and after wl_data_device.drop. Drag-and-drop destination

clients may preemptively fetch data or examine it more closely to

determine acceptance.

</description>

<arg name="mime_type" type="string" summary="mime type desired by receiver"/>

<arg name="fd" type="fd" summary="file descriptor for data transfer"/>

</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" summary="offered mime type"/>

</event>

<!-- Version 3 additions -->

<request name="finish" since="3">

<description summary="the offer will no longer be used">

Notifies the compositor that the drag destination successfully

finished the drag-and-drop operation.

Upon receiving this request, the compositor will emit

wl_data_source.dnd_finished on the drag source client.

It is a client error to perform other requests than

wl_data_offer.destroy after this one. It is also an error to perform

this request after a NULL mime type has been set in

wl_data_offer.accept or no action was received through

wl_data_offer.action.

</description>

</request>

<request name="set_actions" since="3">

<description summary="set the available/preferred drag-and-drop actions">

Sets the actions that the destination side client supports for

this operation. This request may trigger the emission of

wl_data_source.action and wl_data_offer.action events if the compositor

needs to change the selected action.

This request can be called multiple times throughout the

drag-and-drop operation, typically in response to wl_data_device.enter

or wl_data_device.motion events.

This request determines the final result of the drag-and-drop

operation. If the end result is that no action is accepted,

the drag source will receive wl_drag_source.cancelled.

The dnd_actions argument must contain only values expressed in the

wl_data_device_manager.dnd_actions enum, and the preferred_action

argument must only contain one of those values set, otherwise it

will result in a protocol error.

While managing an "ask" action, the destination drag-and-drop client

may perform further wl_data_offer.receive requests, and is expected

to perform one last wl_data_offer.set_actions request with a preferred

action other than "ask" (and optionally wl_data_offer.accept) before

requesting wl_data_offer.finish, in order to convey the action selected

by the user. If the preferred action is not in the

wl_data_offer.source_actions mask, an error will be raised.

If the "ask" action is dismissed (e.g. user cancellation), the client

is expected to perform wl_data_offer.destroy right away.

This request can only be made on drag-and-drop offers, a protocol error

will be raised otherwise.

</description>

<arg name="dnd_actions" type="uint" summary="actions supported by the destination client"/>

<arg name="preferred_action" type="uint" summary="action preferred by the destination client"/>

</request>

<event name="source_actions" since="3">

<description summary="notify the source-side available actions">

This event indicates the actions offered by the data source. It

will be sent right after wl_data_device.enter, or anytime the source

side changes its offered actions through wl_data_source.set_actions.

</description>

<arg name="source_actions" type="uint" summary="actions offered by the data source"/>

</event>

<event name="action" since="3">

<description summary="notify the selected action">

This event indicates the action selected by the compositor after

matching the source/destination side actions. Only one action (or

none) will be offered here.

This event can be emitted multiple times during the drag-and-drop

operation in response to destination side action changes through

wl_data_offer.set_actions.

This event will no longer be emitted after wl_data_device.drop

happened on the drag-and-drop destination, the client must

honor the last action received, or the last preferred one set

through wl_data_offer.set_actions when handling an "ask" action.

Compositors may also change the selected action on the fly, mainly

in response to keyboard modifier changes during the drag-and-drop

operation.

The most recent action received is always the valid one. Prior to

receiving wl_data_device.drop, the chosen action may change (e.g.

due to keyboard modifiers being pressed). At the time of receiving

wl_data_device.drop the drag-and-drop destination must honor the

last action received.

Action changes may still happen after wl_data_device.drop,

especially on "ask" actions, where the drag-and-drop destination

may choose another action afterwards. Action changes happening

at this stage are always the result of inter-client negotiation, the

compositor shall no longer be able to induce a different action.

Upon "ask" actions, it is expected that the drag-and-drop destination

may potentially choose a different action and/or mime type,

based on wl_data_offer.source_actions and finally chosen by the

user (e.g. popping up a menu with the available options). The

final wl_data_offer.set_actions and wl_data_offer.accept requests

must happen before the call to wl_data_offer.finish.

</description>

<arg name="dnd_action" type="uint" summary="action selected by the compositor"/>

</event>

</interface>

<interface name="wl_data_source" version="3">

<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>

<enum name="error">

<entry name="invalid_action_mask" value="0"

summary="action mask contains invalid values"/>

<entry name="invalid_source" value="1"

summary="source doesn't accept this request"/>

</enum>

<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" summary="mime type offered by the data source"/>

</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" summary="mime type accepted by the target"/>

</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" summary="mime type for the data"/>

<arg name="fd" type="fd" summary="file descriptor for the data"/>

</event>

<event name="cancelled">

<description summary="selection was cancelled">

This data source is no longer valid. There are several reasons why

this could happen:

- The data source has been replaced by another data source.

- The drag-and-drop operation was performed, but the drop destination

did not accept any of the mime types offered through

wl_data_source.target.

- The drag-and-drop operation was performed, but the drop destination

did not select any of the actions present in the mask offered through

wl_data_source.action.

- The drag-and-drop operation was performed but didn't happen over a

surface.

- The compositor cancelled the drag-and-drop operation (e.g. compositor

dependent timeouts to avoid stale drag-and-drop transfers).

The client should clean up and destroy this data source.

For objects of version 2 or older, wl_data_source.cancelled will

only be emitted if the data source was replaced by another data

source.

</description>

</event>

<!-- Version 3 additions -->

<request name="set_actions" since="3">

<description summary="set the available drag-and-drop actions">

Sets the actions that the source side client supports for this

operation. This request may trigger wl_data_source.action and

wl_data_offer.action events if the compositor needs to change the

selected action.

The dnd_actions argument must contain only values expressed in the

wl_data_device_manager.dnd_actions enum, otherwise it will result

in a protocol error.

This request must be made once only, and can only be made on sources

used in drag-and-drop, so it must be performed before

wl_data_device.start_drag. Attempting to use the source other than

for drag-and-drop will raise a protocol error.

</description>

<arg name="dnd_actions" type="uint" summary="actions supported by the data source"/>

</request>

<event name="dnd_drop_performed" since="3">

<description summary="the drag-and-drop operation physically finished">

The user performed the drop action. This event does not indicate

acceptance, wl_data_source.cancelled may still be emitted afterwards

if the drop destination does not accept any mime type.

However, this event might however not be received if the compositor

cancelled the drag-and-drop operation before this event could happen.

Note that the data_source may still be used in the future and should

not be destroyed here.

</description>

</event>

<event name="dnd_finished" since="3">

<description summary="the drag-and-drop operation concluded">

The drop destination finished interoperating with this data

source, so the client is now free to destroy this data source and

free all associated data.

If the action used to perform the operation was "move", the

source can now delete the transferred data.

</description>

</event>

<event name="action" since="3">

<description summary="notify the selected action">

This event indicates the action selected by the compositor after

matching the source/destination side actions. Only one action (or

none) will be offered here.

This event can be emitted multiple times during the drag-and-drop

operation, mainly in response to destination side changes through

wl_data_offer.set_actions, and as the data device enters/leaves

surfaces.

It is only possible to receive this event after

wl_data_source.dnd_drop_performed if the drag-and-drop operation

ended in an "ask" action, in which case the final wl_data_source.action

event will happen immediately before wl_data_source.dnd_finished.

Compositors may also change the selected action on the fly, mainly

in response to keyboard modifier changes during the drag-and-drop

operation.

The most recent action received is always the valid one. The chosen

action may change alongside negotiation (e.g. an "ask" action can turn

into a "move" operation), so the effects of the final action must

always be applied in wl_data_offer.dnd_finished.

Clients can trigger cursor surface changes from this point, so

they reflect the current action.

</description>

<arg name="dnd_action" type="uint" summary="action selected by the compositor"/>

</event>

</interface>

<interface name="wl_data_device" version="3">

<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>

<enum name="error">

<entry name="role" value="0" summary="given wl_surface has another role"/>

</enum>

<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 icon surface is given the role of

a drag-and-drop icon. If the icon surface already has another role,

it raises a protocol error.

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 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" summary="data source for the eventual transfer"/>

<arg name="origin" type="object" interface="wl_surface" summary="surface where the drag originates"/>

<arg name="icon" type="object" interface="wl_surface" allow-null="true" summary="drag-and-drop icon surface"/>

<arg name="serial" type="uint" summary="serial number 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" summary="data source for the selection"/>

<arg name="serial" type="uint" summary="serial number 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" summary="the new data_offer object"/>

</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 and y arguments, in surface-local

coordinates.

</description>

<arg name="serial" type="uint" summary="serial number of the enter event"/>

<arg name="surface" type="object" interface="wl_surface" summary="client surface entered"/>

<arg name="x" type="fixed" summary="surface-local x coordinate"/>

<arg name="y" type="fixed" summary="surface-local y coordinate"/>

<arg name="id" type="object" interface="wl_data_offer" allow-null="true"

summary="source data_offer object"/>

</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 and y arguments, in surface-local

coordinates.

</description>

<arg name="time" type="uint" summary="timestamp with millisecond granularity"/>

<arg name="x" type="fixed" summary="surface-local x coordinate"/>

<arg name="y" type="fixed" summary="surface-local y coordinate"/>

</event>

<event name="drop">

<description summary="end drag-and-drop session successfully">

The event is sent when a drag-and-drop operation is ended

because the implicit grab is removed.

The drag-and-drop destination is expected to honor the last action

received through wl_data_offer.action, if the resulting action is

"copy" or "move", the destination can still perform

wl_data_offer.receive requests, and is expected to end all

transfers with a wl_data_offer.finish request.

If the resulting action is "ask", the action will not be considered

final. The drag-and-drop destination is expected to perform one last

wl_data_offer.set_actions request, or wl_data_offer.destroy in order

to cancel the operation.

</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. The client must

destroy the previous selection data_offer, if any, upon receiving

this event.

</description>

<arg name="id" type="object" interface="wl_data_offer" allow-null="true"

summary="selection data_offer object"/>

</event>

<!-- Version 2 additions -->

<request name="release" type="destructor" since="2">

<description summary="destroy data device">

This request destroys the data device.

</description>

</request>

</interface>

<interface name="wl_data_device_manager" version="3">

<description summary="data transfer interface">

The wl_data_device_manager is 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.

Depending on the version bound, the objects created from the bound

wl_data_device_manager object will have different requirements for

functioning properly. See wl_data_source.set_actions,

wl_data_offer.accept and wl_data_offer.finish for details.

</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" summary="data source to create"/>

</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" summary="data device to create"/>

<arg name="seat" type="object" interface="wl_seat" summary="seat associated with the data device"/>

</request>

<!-- Version 3 additions -->

<enum name="dnd_action" bitfield="true" since="3">

<description summary="drag and drop actions">

This is a bitmask of the available/preferred actions in a

drag-and-drop operation.

In the compositor, the selected action is a result of matching the

actions offered by the source and destination sides. "action" events

with a "none" action will be sent to both source and destination if

there is no match. All further checks will effectively happen on

(source actions ∩ destination actions).

In addition, compositors may also pick different actions in

reaction to key modifiers being pressed. One common design that

is used in major toolkits (and the behavior recommended for

compositors) is:

- If no modifiers are pressed, the first match (in bit order)

will be used.

- Pressing Shift selects "move", if enabled in the mask.

- Pressing Control selects "copy", if enabled in the mask.

Behavior beyond that is considered implementation-dependent.

Compositors may for example bind other modifiers (like Alt/Meta)

or drags initiated with other buttons than BTN_LEFT to specific

actions (e.g. "ask").

</description>

<entry name="none" value="0" summary="no action"/>

<entry name="copy" value="1" summary="copy action"/>

<entry name="move" value="2" summary="move action"/>

<entry name="ask" value="4" summary="ask action"/>

</enum>

</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>

<enum name="error">

<entry name="role" value="0" summary="given wl_surface has another role"/>

</enum>

<request name="get_shell_surface">

<description summary="create a shell surface from a surface">

Create a shell surface for an existing surface. This gives

the wl_surface the role of a shell surface. If the wl_surface

already has another role, it raises a protocol error.

Only one shell surface can be associated with a given surface.

</description>

<arg name="id" type="new_id" interface="wl_shell_surface" summary="shell surface to create"/>

<arg name="surface" type="object" interface="wl_surface" summary="surface to be given the shell surface role"/>

</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.