xref: /aosp_15_r20/external/wayland/protocol/wayland.xml (revision 84e872a0dc482bffdb63672969dd03a827d67c73)
1<?xml version="1.0" encoding="UTF-8"?>
2<protocol name="wayland">
3
4  <copyright>
5    Copyright © 2008-2011 Kristian Høgsberg
6    Copyright © 2010-2011 Intel Corporation
7    Copyright © 2012-2013 Collabora, Ltd.
8
9    Permission is hereby granted, free of charge, to any person
10    obtaining a copy of this software and associated documentation files
11    (the "Software"), to deal in the Software without restriction,
12    including without limitation the rights to use, copy, modify, merge,
13    publish, distribute, sublicense, and/or sell copies of the Software,
14    and to permit persons to whom the Software is furnished to do so,
15    subject to the following conditions:
16
17    The above copyright notice and this permission notice (including the
18    next paragraph) shall be included in all copies or substantial
19    portions of the Software.
20
21    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
22    EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
23    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
24    NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
25    BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
26    ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
27    CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
28    SOFTWARE.
29  </copyright>
30
31  <interface name="wl_display" version="1">
32    <description summary="core global object">
33      The core global object.  This is a special singleton object.  It
34      is used for internal Wayland protocol features.
35    </description>
36
37    <request name="sync">
38      <description summary="asynchronous roundtrip">
39	The sync request asks the server to emit the 'done' event
40	on the returned wl_callback object.  Since requests are
41	handled in-order and events are delivered in-order, this can
42	be used as a barrier to ensure all previous requests and the
43	resulting events have been handled.
44
45	The object returned by this request will be destroyed by the
46	compositor after the callback is fired and as such the client must not
47	attempt to use it after that point.
48
49	The callback_data passed in the callback is the event serial.
50      </description>
51      <arg name="callback" type="new_id" interface="wl_callback"
52	   summary="callback object for the sync request"/>
53    </request>
54
55    <request name="get_registry">
56      <description summary="get global registry object">
57	This request creates a registry object that allows the client
58	to list and bind the global objects available from the
59	compositor.
60
61	It should be noted that the server side resources consumed in
62	response to a get_registry request can only be released when the
63	client disconnects, not when the client side proxy is destroyed.
64	Therefore, clients should invoke get_registry as infrequently as
65	possible to avoid wasting memory.
66      </description>
67      <arg name="registry" type="new_id" interface="wl_registry"
68	   summary="global registry object"/>
69    </request>
70
71    <event name="error">
72      <description summary="fatal error event">
73	The error event is sent out when a fatal (non-recoverable)
74	error has occurred.  The object_id argument is the object
75	where the error occurred, most often in response to a request
76	to that object.  The code identifies the error and is defined
77	by the object interface.  As such, each interface defines its
78	own set of error codes.  The message is a brief description
79	of the error, for (debugging) convenience.
80      </description>
81      <arg name="object_id" type="object" summary="object where the error occurred"/>
82      <arg name="code" type="uint" summary="error code"/>
83      <arg name="message" type="string" summary="error description"/>
84    </event>
85
86    <enum name="error">
87      <description summary="global error values">
88	These errors are global and can be emitted in response to any
89	server request.
90      </description>
91      <entry name="invalid_object" value="0"
92	     summary="server couldn't find object"/>
93      <entry name="invalid_method" value="1"
94	     summary="method doesn't exist on the specified interface or malformed request"/>
95      <entry name="no_memory" value="2"
96	     summary="server is out of memory"/>
97      <entry name="implementation" value="3"
98	     summary="implementation error in compositor"/>
99    </enum>
100
101    <event name="delete_id">
102      <description summary="acknowledge object ID deletion">
103	This event is used internally by the object ID management
104	logic. When a client deletes an object that it had created,
105	the server will send this event to acknowledge that it has
106	seen the delete request. When the client receives this event,
107	it will know that it can safely reuse the object ID.
108      </description>
109      <arg name="id" type="uint" summary="deleted object ID"/>
110    </event>
111  </interface>
112
113  <interface name="wl_registry" version="1">
114    <description summary="global registry object">
115      The singleton global registry object.  The server has a number of
116      global objects that are available to all clients.  These objects
117      typically represent an actual object in the server (for example,
118      an input device) or they are singleton objects that provide
119      extension functionality.
120
121      When a client creates a registry object, the registry object
122      will emit a global event for each global currently in the
123      registry.  Globals come and go as a result of device or
124      monitor hotplugs, reconfiguration or other events, and the
125      registry will send out global and global_remove events to
126      keep the client up to date with the changes.  To mark the end
127      of the initial burst of events, the client can use the
128      wl_display.sync request immediately after calling
129      wl_display.get_registry.
130
131      A client can bind to a global object by using the bind
132      request.  This creates a client-side handle that lets the object
133      emit events to the client and lets the client invoke requests on
134      the object.
135    </description>
136
137    <request name="bind">
138      <description summary="bind an object to the display">
139	Binds a new, client-created object to the server using the
140	specified name as the identifier.
141      </description>
142      <arg name="name" type="uint" summary="unique numeric name of the object"/>
143      <arg name="id" type="new_id" summary="bounded object"/>
144    </request>
145
146    <event name="global">
147      <description summary="announce global object">
148	Notify the client of global objects.
149
150	The event notifies the client that a global object with
151	the given name is now available, and it implements the
152	given version of the given interface.
153      </description>
154      <arg name="name" type="uint" summary="numeric name of the global object"/>
155      <arg name="interface" type="string" summary="interface implemented by the object"/>
156      <arg name="version" type="uint" summary="interface version"/>
157    </event>
158
159    <event name="global_remove">
160      <description summary="announce removal of global object">
161	Notify the client of removed global objects.
162
163	This event notifies the client that the global identified
164	by name is no longer available.  If the client bound to
165	the global using the bind request, the client should now
166	destroy that object.
167
168	The object remains valid and requests to the object will be
169	ignored until the client destroys it, to avoid races between
170	the global going away and a client sending a request to it.
171      </description>
172      <arg name="name" type="uint" summary="numeric name of the global object"/>
173    </event>
174  </interface>
175
176  <interface name="wl_callback" version="1">
177    <description summary="callback object">
178      Clients can handle the 'done' event to get notified when
179      the related request is done.
180
181      Note, because wl_callback objects are created from multiple independent
182      factory interfaces, the wl_callback interface is frozen at version 1.
183    </description>
184
185    <event name="done" type="destructor">
186      <description summary="done event">
187	Notify the client when the related request is done.
188      </description>
189      <arg name="callback_data" type="uint" summary="request-specific data for the callback"/>
190    </event>
191  </interface>
192
193  <interface name="wl_compositor" version="6">
194    <description summary="the compositor singleton">
195      A compositor.  This object is a singleton global.  The
196      compositor is in charge of combining the contents of multiple
197      surfaces into one displayable output.
198    </description>
199
200    <request name="create_surface">
201      <description summary="create new surface">
202	Ask the compositor to create a new surface.
203      </description>
204      <arg name="id" type="new_id" interface="wl_surface" summary="the new surface"/>
205    </request>
206
207    <request name="create_region">
208      <description summary="create new region">
209	Ask the compositor to create a new region.
210      </description>
211      <arg name="id" type="new_id" interface="wl_region" summary="the new region"/>
212    </request>
213  </interface>
214
215  <interface name="wl_shm_pool" version="1">
216    <description summary="a shared memory pool">
217      The wl_shm_pool object encapsulates a piece of memory shared
218      between the compositor and client.  Through the wl_shm_pool
219      object, the client can allocate shared memory wl_buffer objects.
220      All objects created through the same pool share the same
221      underlying mapped memory. Reusing the mapped memory avoids the
222      setup/teardown overhead and is useful when interactively resizing
223      a surface or for many small buffers.
224    </description>
225
226    <request name="create_buffer">
227      <description summary="create a buffer from the pool">
228	Create a wl_buffer object from the pool.
229
230	The buffer is created offset bytes into the pool and has
231	width and height as specified.  The stride argument specifies
232	the number of bytes from the beginning of one row to the beginning
233	of the next.  The format is the pixel format of the buffer and
234	must be one of those advertised through the wl_shm.format event.
235
236	A buffer will keep a reference to the pool it was created from
237	so it is valid to destroy the pool immediately after creating
238	a buffer from it.
239      </description>
240      <arg name="id" type="new_id" interface="wl_buffer" summary="buffer to create"/>
241      <arg name="offset" type="int" summary="buffer byte offset within the pool"/>
242      <arg name="width" type="int" summary="buffer width, in pixels"/>
243      <arg name="height" type="int" summary="buffer height, in pixels"/>
244      <arg name="stride" type="int" summary="number of bytes from the beginning of one row to the beginning of the next row"/>
245      <arg name="format" type="uint" enum="wl_shm.format" summary="buffer pixel format"/>
246    </request>
247
248    <request name="destroy" type="destructor">
249      <description summary="destroy the pool">
250	Destroy the shared memory pool.
251
252	The mmapped memory will be released when all
253	buffers that have been created from this pool
254	are gone.
255      </description>
256    </request>
257
258    <request name="resize">
259      <description summary="change the size of the pool mapping">
260	This request will cause the server to remap the backing memory
261	for the pool from the file descriptor passed when the pool was
262	created, but using the new size.  This request can only be
263	used to make the pool bigger.
264
265        This request only changes the amount of bytes that are mmapped
266        by the server and does not touch the file corresponding to the
267        file descriptor passed at creation time. It is the client's
268        responsibility to ensure that the file is at least as big as
269        the new pool size.
270      </description>
271      <arg name="size" type="int" summary="new size of the pool, in bytes"/>
272    </request>
273  </interface>
274
275  <interface name="wl_shm" version="1">
276    <description summary="shared memory support">
277      A singleton global object that provides support for shared
278      memory.
279
280      Clients can create wl_shm_pool objects using the create_pool
281      request.
282
283      On binding the wl_shm object one or more format events
284      are emitted to inform clients about the valid pixel formats
285      that can be used for buffers.
286    </description>
287
288    <enum name="error">
289      <description summary="wl_shm error values">
290	These errors can be emitted in response to wl_shm requests.
291      </description>
292      <entry name="invalid_format" value="0" summary="buffer format is not known"/>
293      <entry name="invalid_stride" value="1" summary="invalid size or stride during pool or buffer creation"/>
294      <entry name="invalid_fd" value="2" summary="mmapping the file descriptor failed"/>
295    </enum>
296
297    <enum name="format">
298      <description summary="pixel formats">
299	This describes the memory layout of an individual pixel.
300
301	All renderers should support argb8888 and xrgb8888 but any other
302	formats are optional and may not be supported by the particular
303	renderer in use.
304
305	The drm format codes match the macros defined in drm_fourcc.h, except
306	argb8888 and xrgb8888. The formats actually supported by the compositor
307	will be reported by the format event.
308
309	For all wl_shm formats and unless specified in another protocol
310	extension, pre-multiplied alpha is used for pixel values.
311      </description>
312      <!-- Note to protocol writers: don't update this list manually, instead
313	   run the automated script that keeps it in sync with drm_fourcc.h. -->
314      <entry name="argb8888" value="0" summary="32-bit ARGB format, [31:0] A:R:G:B 8:8:8:8 little endian"/>
315      <entry name="xrgb8888" value="1" summary="32-bit RGB format, [31:0] x:R:G:B 8:8:8:8 little endian"/>
316      <entry name="c8" value="0x20203843" summary="8-bit color index format, [7:0] C"/>
317      <entry name="rgb332" value="0x38424752" summary="8-bit RGB format, [7:0] R:G:B 3:3:2"/>
318      <entry name="bgr233" value="0x38524742" summary="8-bit BGR format, [7:0] B:G:R 2:3:3"/>
319      <entry name="xrgb4444" value="0x32315258" summary="16-bit xRGB format, [15:0] x:R:G:B 4:4:4:4 little endian"/>
320      <entry name="xbgr4444" value="0x32314258" summary="16-bit xBGR format, [15:0] x:B:G:R 4:4:4:4 little endian"/>
321      <entry name="rgbx4444" value="0x32315852" summary="16-bit RGBx format, [15:0] R:G:B:x 4:4:4:4 little endian"/>
322      <entry name="bgrx4444" value="0x32315842" summary="16-bit BGRx format, [15:0] B:G:R:x 4:4:4:4 little endian"/>
323      <entry name="argb4444" value="0x32315241" summary="16-bit ARGB format, [15:0] A:R:G:B 4:4:4:4 little endian"/>
324      <entry name="abgr4444" value="0x32314241" summary="16-bit ABGR format, [15:0] A:B:G:R 4:4:4:4 little endian"/>
325      <entry name="rgba4444" value="0x32314152" summary="16-bit RBGA format, [15:0] R:G:B:A 4:4:4:4 little endian"/>
326      <entry name="bgra4444" value="0x32314142" summary="16-bit BGRA format, [15:0] B:G:R:A 4:4:4:4 little endian"/>
327      <entry name="xrgb1555" value="0x35315258" summary="16-bit xRGB format, [15:0] x:R:G:B 1:5:5:5 little endian"/>
328      <entry name="xbgr1555" value="0x35314258" summary="16-bit xBGR 1555 format, [15:0] x:B:G:R 1:5:5:5 little endian"/>
329      <entry name="rgbx5551" value="0x35315852" summary="16-bit RGBx 5551 format, [15:0] R:G:B:x 5:5:5:1 little endian"/>
330      <entry name="bgrx5551" value="0x35315842" summary="16-bit BGRx 5551 format, [15:0] B:G:R:x 5:5:5:1 little endian"/>
331      <entry name="argb1555" value="0x35315241" summary="16-bit ARGB 1555 format, [15:0] A:R:G:B 1:5:5:5 little endian"/>
332      <entry name="abgr1555" value="0x35314241" summary="16-bit ABGR 1555 format, [15:0] A:B:G:R 1:5:5:5 little endian"/>
333      <entry name="rgba5551" value="0x35314152" summary="16-bit RGBA 5551 format, [15:0] R:G:B:A 5:5:5:1 little endian"/>
334      <entry name="bgra5551" value="0x35314142" summary="16-bit BGRA 5551 format, [15:0] B:G:R:A 5:5:5:1 little endian"/>
335      <entry name="rgb565" value="0x36314752" summary="16-bit RGB 565 format, [15:0] R:G:B 5:6:5 little endian"/>
336      <entry name="bgr565" value="0x36314742" summary="16-bit BGR 565 format, [15:0] B:G:R 5:6:5 little endian"/>
337      <entry name="rgb888" value="0x34324752" summary="24-bit RGB format, [23:0] R:G:B little endian"/>
338      <entry name="bgr888" value="0x34324742" summary="24-bit BGR format, [23:0] B:G:R little endian"/>
339      <entry name="xbgr8888" value="0x34324258" summary="32-bit xBGR format, [31:0] x:B:G:R 8:8:8:8 little endian"/>
340      <entry name="rgbx8888" value="0x34325852" summary="32-bit RGBx format, [31:0] R:G:B:x 8:8:8:8 little endian"/>
341      <entry name="bgrx8888" value="0x34325842" summary="32-bit BGRx format, [31:0] B:G:R:x 8:8:8:8 little endian"/>
342      <entry name="abgr8888" value="0x34324241" summary="32-bit ABGR format, [31:0] A:B:G:R 8:8:8:8 little endian"/>
343      <entry name="rgba8888" value="0x34324152" summary="32-bit RGBA format, [31:0] R:G:B:A 8:8:8:8 little endian"/>
344      <entry name="bgra8888" value="0x34324142" summary="32-bit BGRA format, [31:0] B:G:R:A 8:8:8:8 little endian"/>
345      <entry name="xrgb2101010" value="0x30335258" summary="32-bit xRGB format, [31:0] x:R:G:B 2:10:10:10 little endian"/>
346      <entry name="xbgr2101010" value="0x30334258" summary="32-bit xBGR format, [31:0] x:B:G:R 2:10:10:10 little endian"/>
347      <entry name="rgbx1010102" value="0x30335852" summary="32-bit RGBx format, [31:0] R:G:B:x 10:10:10:2 little endian"/>
348      <entry name="bgrx1010102" value="0x30335842" summary="32-bit BGRx format, [31:0] B:G:R:x 10:10:10:2 little endian"/>
349      <entry name="argb2101010" value="0x30335241" summary="32-bit ARGB format, [31:0] A:R:G:B 2:10:10:10 little endian"/>
350      <entry name="abgr2101010" value="0x30334241" summary="32-bit ABGR format, [31:0] A:B:G:R 2:10:10:10 little endian"/>
351      <entry name="rgba1010102" value="0x30334152" summary="32-bit RGBA format, [31:0] R:G:B:A 10:10:10:2 little endian"/>
352      <entry name="bgra1010102" value="0x30334142" summary="32-bit BGRA format, [31:0] B:G:R:A 10:10:10:2 little endian"/>
353      <entry name="yuyv" value="0x56595559" summary="packed YCbCr format, [31:0] Cr0:Y1:Cb0:Y0 8:8:8:8 little endian"/>
354      <entry name="yvyu" value="0x55595659" summary="packed YCbCr format, [31:0] Cb0:Y1:Cr0:Y0 8:8:8:8 little endian"/>
355      <entry name="uyvy" value="0x59565955" summary="packed YCbCr format, [31:0] Y1:Cr0:Y0:Cb0 8:8:8:8 little endian"/>
356      <entry name="vyuy" value="0x59555956" summary="packed YCbCr format, [31:0] Y1:Cb0:Y0:Cr0 8:8:8:8 little endian"/>
357      <entry name="ayuv" value="0x56555941" summary="packed AYCbCr format, [31:0] A:Y:Cb:Cr 8:8:8:8 little endian"/>
358      <entry name="nv12" value="0x3231564e" summary="2 plane YCbCr Cr:Cb format, 2x2 subsampled Cr:Cb plane"/>
359      <entry name="nv21" value="0x3132564e" summary="2 plane YCbCr Cb:Cr format, 2x2 subsampled Cb:Cr plane"/>
360      <entry name="nv16" value="0x3631564e" summary="2 plane YCbCr Cr:Cb format, 2x1 subsampled Cr:Cb plane"/>
361      <entry name="nv61" value="0x3136564e" summary="2 plane YCbCr Cb:Cr format, 2x1 subsampled Cb:Cr plane"/>
362      <entry name="yuv410" value="0x39565559" summary="3 plane YCbCr format, 4x4 subsampled Cb (1) and Cr (2) planes"/>
363      <entry name="yvu410" value="0x39555659" summary="3 plane YCbCr format, 4x4 subsampled Cr (1) and Cb (2) planes"/>
364      <entry name="yuv411" value="0x31315559" summary="3 plane YCbCr format, 4x1 subsampled Cb (1) and Cr (2) planes"/>
365      <entry name="yvu411" value="0x31315659" summary="3 plane YCbCr format, 4x1 subsampled Cr (1) and Cb (2) planes"/>
366      <entry name="yuv420" value="0x32315559" summary="3 plane YCbCr format, 2x2 subsampled Cb (1) and Cr (2) planes"/>
367      <entry name="yvu420" value="0x32315659" summary="3 plane YCbCr format, 2x2 subsampled Cr (1) and Cb (2) planes"/>
368      <entry name="yuv422" value="0x36315559" summary="3 plane YCbCr format, 2x1 subsampled Cb (1) and Cr (2) planes"/>
369      <entry name="yvu422" value="0x36315659" summary="3 plane YCbCr format, 2x1 subsampled Cr (1) and Cb (2) planes"/>
370      <entry name="yuv444" value="0x34325559" summary="3 plane YCbCr format, non-subsampled Cb (1) and Cr (2) planes"/>
371      <entry name="yvu444" value="0x34325659" summary="3 plane YCbCr format, non-subsampled Cr (1) and Cb (2) planes"/>
372      <entry name="r8" value="0x20203852" summary="[7:0] R"/>
373      <entry name="r16" value="0x20363152" summary="[15:0] R little endian"/>
374      <entry name="rg88" value="0x38384752" summary="[15:0] R:G 8:8 little endian"/>
375      <entry name="gr88" value="0x38385247" summary="[15:0] G:R 8:8 little endian"/>
376      <entry name="rg1616" value="0x32334752" summary="[31:0] R:G 16:16 little endian"/>
377      <entry name="gr1616" value="0x32335247" summary="[31:0] G:R 16:16 little endian"/>
378      <entry name="xrgb16161616f" value="0x48345258" summary="[63:0] x:R:G:B 16:16:16:16 little endian"/>
379      <entry name="xbgr16161616f" value="0x48344258" summary="[63:0] x:B:G:R 16:16:16:16 little endian"/>
380      <entry name="argb16161616f" value="0x48345241" summary="[63:0] A:R:G:B 16:16:16:16 little endian"/>
381      <entry name="abgr16161616f" value="0x48344241" summary="[63:0] A:B:G:R 16:16:16:16 little endian"/>
382      <entry name="xyuv8888" value="0x56555958" summary="[31:0] X:Y:Cb:Cr 8:8:8:8 little endian"/>
383      <entry name="vuy888" value="0x34325556" summary="[23:0] Cr:Cb:Y 8:8:8 little endian"/>
384      <entry name="vuy101010" value="0x30335556" summary="Y followed by U then V, 10:10:10. Non-linear modifier only"/>
385      <entry name="y210" value="0x30313259" summary="[63:0] Cr0:0:Y1:0:Cb0:0:Y0:0 10:6:10:6:10:6:10:6 little endian per 2 Y pixels"/>
386      <entry name="y212" value="0x32313259" summary="[63:0] Cr0:0:Y1:0:Cb0:0:Y0:0 12:4:12:4:12:4:12:4 little endian per 2 Y pixels"/>
387      <entry name="y216" value="0x36313259" summary="[63:0] Cr0:Y1:Cb0:Y0 16:16:16:16 little endian per 2 Y pixels"/>
388      <entry name="y410" value="0x30313459" summary="[31:0] A:Cr:Y:Cb 2:10:10:10 little endian"/>
389      <entry name="y412" value="0x32313459" summary="[63:0] A:0:Cr:0:Y:0:Cb:0 12:4:12:4:12:4:12:4 little endian"/>
390      <entry name="y416" value="0x36313459" summary="[63:0] A:Cr:Y:Cb 16:16:16:16 little endian"/>
391      <entry name="xvyu2101010" value="0x30335658" summary="[31:0] X:Cr:Y:Cb 2:10:10:10 little endian"/>
392      <entry name="xvyu12_16161616" value="0x36335658" summary="[63:0] X:0:Cr:0:Y:0:Cb:0 12:4:12:4:12:4:12:4 little endian"/>
393      <entry name="xvyu16161616" value="0x38345658" summary="[63:0] X:Cr:Y:Cb 16:16:16:16 little endian"/>
394      <entry name="y0l0" value="0x304c3059" summary="[63:0]   A3:A2:Y3:0:Cr0:0:Y2:0:A1:A0:Y1:0:Cb0:0:Y0:0  1:1:8:2:8:2:8:2:1:1:8:2:8:2:8:2 little endian"/>
395      <entry name="x0l0" value="0x304c3058" summary="[63:0]   X3:X2:Y3:0:Cr0:0:Y2:0:X1:X0:Y1:0:Cb0:0:Y0:0  1:1:8:2:8:2:8:2:1:1:8:2:8:2:8:2 little endian"/>
396      <entry name="y0l2" value="0x324c3059" summary="[63:0]   A3:A2:Y3:Cr0:Y2:A1:A0:Y1:Cb0:Y0  1:1:10:10:10:1:1:10:10:10 little endian"/>
397      <entry name="x0l2" value="0x324c3058" summary="[63:0]   X3:X2:Y3:Cr0:Y2:X1:X0:Y1:Cb0:Y0  1:1:10:10:10:1:1:10:10:10 little endian"/>
398      <entry name="yuv420_8bit" value="0x38305559"/>
399      <entry name="yuv420_10bit" value="0x30315559"/>
400      <entry name="xrgb8888_a8" value="0x38415258"/>
401      <entry name="xbgr8888_a8" value="0x38414258"/>
402      <entry name="rgbx8888_a8" value="0x38415852"/>
403      <entry name="bgrx8888_a8" value="0x38415842"/>
404      <entry name="rgb888_a8" value="0x38413852"/>
405      <entry name="bgr888_a8" value="0x38413842"/>
406      <entry name="rgb565_a8" value="0x38413552"/>
407      <entry name="bgr565_a8" value="0x38413542"/>
408      <entry name="nv24" value="0x3432564e" summary="non-subsampled Cr:Cb plane"/>
409      <entry name="nv42" value="0x3234564e" summary="non-subsampled Cb:Cr plane"/>
410      <entry name="p210" value="0x30313250" summary="2x1 subsampled Cr:Cb plane, 10 bit per channel"/>
411      <entry name="p010" value="0x30313050" summary="2x2 subsampled Cr:Cb plane 10 bits per channel"/>
412      <entry name="p012" value="0x32313050" summary="2x2 subsampled Cr:Cb plane 12 bits per channel"/>
413      <entry name="p016" value="0x36313050" summary="2x2 subsampled Cr:Cb plane 16 bits per channel"/>
414      <entry name="axbxgxrx106106106106" value="0x30314241" summary="[63:0] A:x:B:x:G:x:R:x 10:6:10:6:10:6:10:6 little endian"/>
415      <entry name="nv15" value="0x3531564e" summary="2x2 subsampled Cr:Cb plane"/>
416      <entry name="q410" value="0x30313451"/>
417      <entry name="q401" value="0x31303451"/>
418      <entry name="xrgb16161616" value="0x38345258" summary="[63:0] x:R:G:B 16:16:16:16 little endian"/>
419      <entry name="xbgr16161616" value="0x38344258" summary="[63:0] x:B:G:R 16:16:16:16 little endian"/>
420      <entry name="argb16161616" value="0x38345241" summary="[63:0] A:R:G:B 16:16:16:16 little endian"/>
421      <entry name="abgr16161616" value="0x38344241" summary="[63:0] A:B:G:R 16:16:16:16 little endian"/>
422    </enum>
423
424    <request name="create_pool">
425      <description summary="create a shm pool">
426	Create a new wl_shm_pool object.
427
428	The pool can be used to create shared memory based buffer
429	objects.  The server will mmap size bytes of the passed file
430	descriptor, to use as backing memory for the pool.
431      </description>
432      <arg name="id" type="new_id" interface="wl_shm_pool" summary="pool to create"/>
433      <arg name="fd" type="fd" summary="file descriptor for the pool"/>
434      <arg name="size" type="int" summary="pool size, in bytes"/>
435    </request>
436
437    <event name="format">
438      <description summary="pixel format description">
439	Informs the client about a valid pixel format that
440	can be used for buffers. Known formats include
441	argb8888 and xrgb8888.
442      </description>
443      <arg name="format" type="uint" enum="format" summary="buffer pixel format"/>
444    </event>
445  </interface>
446
447  <interface name="wl_buffer" version="1">
448    <description summary="content for a wl_surface">
449      A buffer provides the content for a wl_surface. Buffers are
450      created through factory interfaces such as wl_shm, wp_linux_buffer_params
451      (from the linux-dmabuf protocol extension) or similar. It has a width and
452      a height and can be attached to a wl_surface, but the mechanism by which a
453      client provides and updates the contents is defined by the buffer factory
454      interface.
455
456      If the buffer uses a format that has an alpha channel, the alpha channel
457      is assumed to be premultiplied in the color channels unless otherwise
458      specified.
459
460      Note, because wl_buffer objects are created from multiple independent
461      factory interfaces, the wl_buffer interface is frozen at version 1.
462    </description>
463
464    <request name="destroy" type="destructor">
465      <description summary="destroy a buffer">
466	Destroy a buffer. If and how you need to release the backing
467	storage is defined by the buffer factory interface.
468
469	For possible side-effects to a surface, see wl_surface.attach.
470      </description>
471    </request>
472
473    <event name="release">
474      <description summary="compositor releases buffer">
475	Sent when this wl_buffer is no longer used by the compositor.
476	The client is now free to reuse or destroy this buffer and its
477	backing storage.
478
479	If a client receives a release event before the frame callback
480	requested in the same wl_surface.commit that attaches this
481	wl_buffer to a surface, then the client is immediately free to
482	reuse the buffer and its backing storage, and does not need a
483	second buffer for the next surface content update. Typically
484	this is possible, when the compositor maintains a copy of the
485	wl_surface contents, e.g. as a GL texture. This is an important
486	optimization for GL(ES) compositors with wl_shm clients.
487      </description>
488    </event>
489  </interface>
490
491  <interface name="wl_data_offer" version="3">
492    <description summary="offer to transfer data">
493      A wl_data_offer represents a piece of data offered for transfer
494      by another client (the source client).  It is used by the
495      copy-and-paste and drag-and-drop mechanisms.  The offer
496      describes the different mime types that the data can be
497      converted to and provides the mechanism for transferring the
498      data directly from the source client.
499    </description>
500
501    <enum name="error">
502      <entry name="invalid_finish" value="0"
503	     summary="finish request was called untimely"/>
504      <entry name="invalid_action_mask" value="1"
505	     summary="action mask contains invalid values"/>
506      <entry name="invalid_action" value="2"
507	     summary="action argument has an invalid value"/>
508      <entry name="invalid_offer" value="3"
509	     summary="offer doesn't accept this request"/>
510    </enum>
511
512    <request name="accept">
513      <description summary="accept one of the offered mime types">
514	Indicate that the client can accept the given mime type, or
515	NULL for not accepted.
516
517	For objects of version 2 or older, this request is used by the
518	client to give feedback whether the client can receive the given
519	mime type, or NULL if none is accepted; the feedback does not
520	determine whether the drag-and-drop operation succeeds or not.
521
522	For objects of version 3 or newer, this request determines the
523	final result of the drag-and-drop operation. If the end result
524	is that no mime types were accepted, the drag-and-drop operation
525	will be cancelled and the corresponding drag source will receive
526	wl_data_source.cancelled. Clients may still use this event in
527	conjunction with wl_data_source.action for feedback.
528      </description>
529      <arg name="serial" type="uint" summary="serial number of the accept request"/>
530      <arg name="mime_type" type="string" allow-null="true" summary="mime type accepted by the client"/>
531    </request>
532
533    <request name="receive">
534      <description summary="request that the data is transferred">
535	To transfer the offered data, the client issues this request
536	and indicates the mime type it wants to receive.  The transfer
537	happens through the passed file descriptor (typically created
538	with the pipe system call).  The source client writes the data
539	in the mime type representation requested and then closes the
540	file descriptor.
541
542	The receiving client reads from the read end of the pipe until
543	EOF and then closes its end, at which point the transfer is
544	complete.
545
546	This request may happen multiple times for different mime types,
547	both before and after wl_data_device.drop. Drag-and-drop destination
548	clients may preemptively fetch data or examine it more closely to
549	determine acceptance.
550      </description>
551      <arg name="mime_type" type="string" summary="mime type desired by receiver"/>
552      <arg name="fd" type="fd" summary="file descriptor for data transfer"/>
553    </request>
554
555    <request name="destroy" type="destructor">
556      <description summary="destroy data offer">
557	Destroy the data offer.
558      </description>
559    </request>
560
561    <event name="offer">
562      <description summary="advertise offered mime type">
563	Sent immediately after creating the wl_data_offer object.  One
564	event per offered mime type.
565      </description>
566      <arg name="mime_type" type="string" summary="offered mime type"/>
567    </event>
568
569    <!-- Version 3 additions -->
570
571    <request name="finish" since="3">
572      <description summary="the offer will no longer be used">
573	Notifies the compositor that the drag destination successfully
574	finished the drag-and-drop operation.
575
576	Upon receiving this request, the compositor will emit
577	wl_data_source.dnd_finished on the drag source client.
578
579	It is a client error to perform other requests than
580	wl_data_offer.destroy after this one. It is also an error to perform
581	this request after a NULL mime type has been set in
582	wl_data_offer.accept or no action was received through
583	wl_data_offer.action.
584
585	If wl_data_offer.finish request is received for a non drag and drop
586	operation, the invalid_finish protocol error is raised.
587      </description>
588    </request>
589
590    <request name="set_actions" since="3">
591      <description summary="set the available/preferred drag-and-drop actions">
592	Sets the actions that the destination side client supports for
593	this operation. This request may trigger the emission of
594	wl_data_source.action and wl_data_offer.action events if the compositor
595	needs to change the selected action.
596
597	This request can be called multiple times throughout the
598	drag-and-drop operation, typically in response to wl_data_device.enter
599	or wl_data_device.motion events.
600
601	This request determines the final result of the drag-and-drop
602	operation. If the end result is that no action is accepted,
603	the drag source will receive wl_data_source.cancelled.
604
605	The dnd_actions argument must contain only values expressed in the
606	wl_data_device_manager.dnd_actions enum, and the preferred_action
607	argument must only contain one of those values set, otherwise it
608	will result in a protocol error.
609
610	While managing an "ask" action, the destination drag-and-drop client
611	may perform further wl_data_offer.receive requests, and is expected
612	to perform one last wl_data_offer.set_actions request with a preferred
613	action other than "ask" (and optionally wl_data_offer.accept) before
614	requesting wl_data_offer.finish, in order to convey the action selected
615	by the user. If the preferred action is not in the
616	wl_data_offer.source_actions mask, an error will be raised.
617
618	If the "ask" action is dismissed (e.g. user cancellation), the client
619	is expected to perform wl_data_offer.destroy right away.
620
621	This request can only be made on drag-and-drop offers, a protocol error
622	will be raised otherwise.
623      </description>
624      <arg name="dnd_actions" type="uint" summary="actions supported by the destination client"
625	   enum="wl_data_device_manager.dnd_action"/>
626      <arg name="preferred_action" type="uint" summary="action preferred by the destination client"
627	   enum="wl_data_device_manager.dnd_action"/>
628    </request>
629
630    <event name="source_actions" since="3">
631      <description summary="notify the source-side available actions">
632	This event indicates the actions offered by the data source. It
633	will be sent immediately after creating the wl_data_offer object,
634	or anytime the source side changes its offered actions through
635	wl_data_source.set_actions.
636      </description>
637      <arg name="source_actions" type="uint" summary="actions offered by the data source"
638	   enum="wl_data_device_manager.dnd_action"/>
639    </event>
640
641    <event name="action" since="3">
642      <description summary="notify the selected action">
643	This event indicates the action selected by the compositor after
644	matching the source/destination side actions. Only one action (or
645	none) will be offered here.
646
647	This event can be emitted multiple times during the drag-and-drop
648	operation in response to destination side action changes through
649	wl_data_offer.set_actions.
650
651	This event will no longer be emitted after wl_data_device.drop
652	happened on the drag-and-drop destination, the client must
653	honor the last action received, or the last preferred one set
654	through wl_data_offer.set_actions when handling an "ask" action.
655
656	Compositors may also change the selected action on the fly, mainly
657	in response to keyboard modifier changes during the drag-and-drop
658	operation.
659
660	The most recent action received is always the valid one. Prior to
661	receiving wl_data_device.drop, the chosen action may change (e.g.
662	due to keyboard modifiers being pressed). At the time of receiving
663	wl_data_device.drop the drag-and-drop destination must honor the
664	last action received.
665
666	Action changes may still happen after wl_data_device.drop,
667	especially on "ask" actions, where the drag-and-drop destination
668	may choose another action afterwards. Action changes happening
669	at this stage are always the result of inter-client negotiation, the
670	compositor shall no longer be able to induce a different action.
671
672	Upon "ask" actions, it is expected that the drag-and-drop destination
673	may potentially choose a different action and/or mime type,
674	based on wl_data_offer.source_actions and finally chosen by the
675	user (e.g. popping up a menu with the available options). The
676	final wl_data_offer.set_actions and wl_data_offer.accept requests
677	must happen before the call to wl_data_offer.finish.
678      </description>
679      <arg name="dnd_action" type="uint" summary="action selected by the compositor"
680	   enum="wl_data_device_manager.dnd_action"/>
681    </event>
682  </interface>
683
684  <interface name="wl_data_source" version="3">
685    <description summary="offer to transfer data">
686      The wl_data_source object is the source side of a wl_data_offer.
687      It is created by the source client in a data transfer and
688      provides a way to describe the offered data and a way to respond
689      to requests to transfer the data.
690    </description>
691
692    <enum name="error">
693      <entry name="invalid_action_mask" value="0"
694	     summary="action mask contains invalid values"/>
695      <entry name="invalid_source" value="1"
696	     summary="source doesn't accept this request"/>
697    </enum>
698
699    <request name="offer">
700      <description summary="add an offered mime type">
701	This request adds a mime type to the set of mime types
702	advertised to targets.  Can be called several times to offer
703	multiple types.
704      </description>
705      <arg name="mime_type" type="string" summary="mime type offered by the data source"/>
706    </request>
707
708    <request name="destroy" type="destructor">
709      <description summary="destroy the data source">
710	Destroy the data source.
711      </description>
712    </request>
713
714    <event name="target">
715      <description summary="a target accepts an offered mime type">
716	Sent when a target accepts pointer_focus or motion events.  If
717	a target does not accept any of the offered types, type is NULL.
718
719	Used for feedback during drag-and-drop.
720      </description>
721      <arg name="mime_type" type="string" allow-null="true" summary="mime type accepted by the target"/>
722    </event>
723
724    <event name="send">
725      <description summary="send the data">
726	Request for data from the client.  Send the data as the
727	specified mime type over the passed file descriptor, then
728	close it.
729      </description>
730      <arg name="mime_type" type="string" summary="mime type for the data"/>
731      <arg name="fd" type="fd" summary="file descriptor for the data"/>
732    </event>
733
734    <event name="cancelled">
735      <description summary="selection was cancelled">
736	This data source is no longer valid. There are several reasons why
737	this could happen:
738
739	- The data source has been replaced by another data source.
740	- The drag-and-drop operation was performed, but the drop destination
741	  did not accept any of the mime types offered through
742	  wl_data_source.target.
743	- The drag-and-drop operation was performed, but the drop destination
744	  did not select any of the actions present in the mask offered through
745	  wl_data_source.action.
746	- The drag-and-drop operation was performed but didn't happen over a
747	  surface.
748	- The compositor cancelled the drag-and-drop operation (e.g. compositor
749	  dependent timeouts to avoid stale drag-and-drop transfers).
750
751	The client should clean up and destroy this data source.
752
753	For objects of version 2 or older, wl_data_source.cancelled will
754	only be emitted if the data source was replaced by another data
755	source.
756      </description>
757    </event>
758
759    <!-- Version 3 additions -->
760
761    <request name="set_actions" since="3">
762      <description summary="set the available drag-and-drop actions">
763	Sets the actions that the source side client supports for this
764	operation. This request may trigger wl_data_source.action and
765	wl_data_offer.action events if the compositor needs to change the
766	selected action.
767
768	The dnd_actions argument must contain only values expressed in the
769	wl_data_device_manager.dnd_actions enum, otherwise it will result
770	in a protocol error.
771
772	This request must be made once only, and can only be made on sources
773	used in drag-and-drop, so it must be performed before
774	wl_data_device.start_drag. Attempting to use the source other than
775	for drag-and-drop will raise a protocol error.
776      </description>
777      <arg name="dnd_actions" type="uint" summary="actions supported by the data source"
778	   enum="wl_data_device_manager.dnd_action"/>
779    </request>
780
781    <event name="dnd_drop_performed" since="3">
782      <description summary="the drag-and-drop operation physically finished">
783	The user performed the drop action. This event does not indicate
784	acceptance, wl_data_source.cancelled may still be emitted afterwards
785	if the drop destination does not accept any mime type.
786
787	However, this event might however not be received if the compositor
788	cancelled the drag-and-drop operation before this event could happen.
789
790	Note that the data_source may still be used in the future and should
791	not be destroyed here.
792      </description>
793    </event>
794
795    <event name="dnd_finished" since="3">
796      <description summary="the drag-and-drop operation concluded">
797	The drop destination finished interoperating with this data
798	source, so the client is now free to destroy this data source and
799	free all associated data.
800
801	If the action used to perform the operation was "move", the
802	source can now delete the transferred data.
803      </description>
804    </event>
805
806    <event name="action" since="3">
807      <description summary="notify the selected action">
808	This event indicates the action selected by the compositor after
809	matching the source/destination side actions. Only one action (or
810	none) will be offered here.
811
812	This event can be emitted multiple times during the drag-and-drop
813	operation, mainly in response to destination side changes through
814	wl_data_offer.set_actions, and as the data device enters/leaves
815	surfaces.
816
817	It is only possible to receive this event after
818	wl_data_source.dnd_drop_performed if the drag-and-drop operation
819	ended in an "ask" action, in which case the final wl_data_source.action
820	event will happen immediately before wl_data_source.dnd_finished.
821
822	Compositors may also change the selected action on the fly, mainly
823	in response to keyboard modifier changes during the drag-and-drop
824	operation.
825
826	The most recent action received is always the valid one. The chosen
827	action may change alongside negotiation (e.g. an "ask" action can turn
828	into a "move" operation), so the effects of the final action must
829	always be applied in wl_data_offer.dnd_finished.
830
831	Clients can trigger cursor surface changes from this point, so
832	they reflect the current action.
833      </description>
834      <arg name="dnd_action" type="uint" summary="action selected by the compositor"
835	   enum="wl_data_device_manager.dnd_action"/>
836    </event>
837  </interface>
838
839  <interface name="wl_data_device" version="3">
840    <description summary="data transfer device">
841      There is one wl_data_device per seat which can be obtained
842      from the global wl_data_device_manager singleton.
843
844      A wl_data_device provides access to inter-client data transfer
845      mechanisms such as copy-and-paste and drag-and-drop.
846    </description>
847
848    <enum name="error">
849      <entry name="role" value="0" summary="given wl_surface has another role"/>
850    </enum>
851
852    <request name="start_drag">
853      <description summary="start drag-and-drop operation">
854	This request asks the compositor to start a drag-and-drop
855	operation on behalf of the client.
856
857	The source argument is the data source that provides the data
858	for the eventual data transfer. If source is NULL, enter, leave
859	and motion events are sent only to the client that initiated the
860	drag and the client is expected to handle the data passing
861	internally. If source is destroyed, the drag-and-drop session will be
862	cancelled.
863
864	The origin surface is the surface where the drag originates and
865	the client must have an active implicit grab that matches the
866	serial.
867
868	The icon surface is an optional (can be NULL) surface that
869	provides an icon to be moved around with the cursor.  Initially,
870	the top-left corner of the icon surface is placed at the cursor
871	hotspot, but subsequent wl_surface.attach request can move the
872	relative position. Attach requests must be confirmed with
873	wl_surface.commit as usual. The icon surface is given the role of
874	a drag-and-drop icon. If the icon surface already has another role,
875	it raises a protocol error.
876
877	The input region is ignored for wl_surfaces with the role of a
878	drag-and-drop icon.
879      </description>
880      <arg name="source" type="object" interface="wl_data_source" allow-null="true" summary="data source for the eventual transfer"/>
881      <arg name="origin" type="object" interface="wl_surface" summary="surface where the drag originates"/>
882      <arg name="icon" type="object" interface="wl_surface" allow-null="true" summary="drag-and-drop icon surface"/>
883      <arg name="serial" type="uint" summary="serial number of the implicit grab on the origin"/>
884    </request>
885
886    <request name="set_selection">
887      <description summary="copy data to the selection">
888	This request asks the compositor to set the selection
889	to the data from the source on behalf of the client.
890
891	To unset the selection, set the source to NULL.
892      </description>
893      <arg name="source" type="object" interface="wl_data_source" allow-null="true" summary="data source for the selection"/>
894      <arg name="serial" type="uint" summary="serial number of the event that triggered this request"/>
895    </request>
896
897    <event name="data_offer">
898      <description summary="introduce a new wl_data_offer">
899	The data_offer event introduces a new wl_data_offer object,
900	which will subsequently be used in either the
901	data_device.enter event (for drag-and-drop) or the
902	data_device.selection event (for selections).  Immediately
903	following the data_device.data_offer event, the new data_offer
904	object will send out data_offer.offer events to describe the
905	mime types it offers.
906      </description>
907      <arg name="id" type="new_id" interface="wl_data_offer" summary="the new data_offer object"/>
908    </event>
909
910    <event name="enter">
911      <description summary="initiate drag-and-drop session">
912	This event is sent when an active drag-and-drop pointer enters
913	a surface owned by the client.  The position of the pointer at
914	enter time is provided by the x and y arguments, in surface-local
915	coordinates.
916      </description>
917      <arg name="serial" type="uint" summary="serial number of the enter event"/>
918      <arg name="surface" type="object" interface="wl_surface" summary="client surface entered"/>
919      <arg name="x" type="fixed" summary="surface-local x coordinate"/>
920      <arg name="y" type="fixed" summary="surface-local y coordinate"/>
921      <arg name="id" type="object" interface="wl_data_offer" allow-null="true"
922	   summary="source data_offer object"/>
923    </event>
924
925    <event name="leave">
926      <description summary="end drag-and-drop session">
927	This event is sent when the drag-and-drop pointer leaves the
928	surface and the session ends.  The client must destroy the
929	wl_data_offer introduced at enter time at this point.
930      </description>
931    </event>
932
933    <event name="motion">
934      <description summary="drag-and-drop session motion">
935	This event is sent when the drag-and-drop pointer moves within
936	the currently focused surface. The new position of the pointer
937	is provided by the x and y arguments, in surface-local
938	coordinates.
939      </description>
940      <arg name="time" type="uint" summary="timestamp with millisecond granularity"/>
941      <arg name="x" type="fixed" summary="surface-local x coordinate"/>
942      <arg name="y" type="fixed" summary="surface-local y coordinate"/>
943    </event>
944
945    <event name="drop">
946      <description summary="end drag-and-drop session successfully">
947	The event is sent when a drag-and-drop operation is ended
948	because the implicit grab is removed.
949
950	The drag-and-drop destination is expected to honor the last action
951	received through wl_data_offer.action, if the resulting action is
952	"copy" or "move", the destination can still perform
953	wl_data_offer.receive requests, and is expected to end all
954	transfers with a wl_data_offer.finish request.
955
956	If the resulting action is "ask", the action will not be considered
957	final. The drag-and-drop destination is expected to perform one last
958	wl_data_offer.set_actions request, or wl_data_offer.destroy in order
959	to cancel the operation.
960      </description>
961    </event>
962
963    <event name="selection">
964      <description summary="advertise new selection">
965	The selection event is sent out to notify the client of a new
966	wl_data_offer for the selection for this device.  The
967	data_device.data_offer and the data_offer.offer events are
968	sent out immediately before this event to introduce the data
969	offer object.  The selection event is sent to a client
970	immediately before receiving keyboard focus and when a new
971	selection is set while the client has keyboard focus.  The
972	data_offer is valid until a new data_offer or NULL is received
973	or until the client loses keyboard focus.  Switching surface with
974	keyboard focus within the same client doesn't mean a new selection
975	will be sent.  The client must destroy the previous selection
976	data_offer, if any, upon receiving this event.
977      </description>
978      <arg name="id" type="object" interface="wl_data_offer" allow-null="true"
979	   summary="selection data_offer object"/>
980    </event>
981
982    <!-- Version 2 additions -->
983
984    <request name="release" type="destructor" since="2">
985      <description summary="destroy data device">
986	This request destroys the data device.
987      </description>
988    </request>
989  </interface>
990
991  <interface name="wl_data_device_manager" version="3">
992    <description summary="data transfer interface">
993      The wl_data_device_manager is a singleton global object that
994      provides access to inter-client data transfer mechanisms such as
995      copy-and-paste and drag-and-drop.  These mechanisms are tied to
996      a wl_seat and this interface lets a client get a wl_data_device
997      corresponding to a wl_seat.
998
999      Depending on the version bound, the objects created from the bound
1000      wl_data_device_manager object will have different requirements for
1001      functioning properly. See wl_data_source.set_actions,
1002      wl_data_offer.accept and wl_data_offer.finish for details.
1003    </description>
1004
1005    <request name="create_data_source">
1006      <description summary="create a new data source">
1007	Create a new data source.
1008      </description>
1009      <arg name="id" type="new_id" interface="wl_data_source" summary="data source to create"/>
1010    </request>
1011
1012    <request name="get_data_device">
1013      <description summary="create a new data device">
1014	Create a new data device for a given seat.
1015      </description>
1016      <arg name="id" type="new_id" interface="wl_data_device" summary="data device to create"/>
1017      <arg name="seat" type="object" interface="wl_seat" summary="seat associated with the data device"/>
1018    </request>
1019
1020    <!-- Version 3 additions -->
1021
1022    <enum name="dnd_action" bitfield="true" since="3">
1023      <description summary="drag and drop actions">
1024	This is a bitmask of the available/preferred actions in a
1025	drag-and-drop operation.
1026
1027	In the compositor, the selected action is a result of matching the
1028	actions offered by the source and destination sides.  "action" events
1029	with a "none" action will be sent to both source and destination if
1030	there is no match. All further checks will effectively happen on
1031	(source actions ∩ destination actions).
1032
1033	In addition, compositors may also pick different actions in
1034	reaction to key modifiers being pressed. One common design that
1035	is used in major toolkits (and the behavior recommended for
1036	compositors) is:
1037
1038	- If no modifiers are pressed, the first match (in bit order)
1039	  will be used.
1040	- Pressing Shift selects "move", if enabled in the mask.
1041	- Pressing Control selects "copy", if enabled in the mask.
1042
1043	Behavior beyond that is considered implementation-dependent.
1044	Compositors may for example bind other modifiers (like Alt/Meta)
1045	or drags initiated with other buttons than BTN_LEFT to specific
1046	actions (e.g. "ask").
1047      </description>
1048      <entry name="none" value="0" summary="no action"/>
1049      <entry name="copy" value="1" summary="copy action"/>
1050      <entry name="move" value="2" summary="move action"/>
1051      <entry name="ask" value="4" summary="ask action"/>
1052    </enum>
1053  </interface>
1054
1055  <interface name="wl_shell" version="1">
1056    <description summary="create desktop-style surfaces">
1057      This interface is implemented by servers that provide
1058      desktop-style user interfaces.
1059
1060      It allows clients to associate a wl_shell_surface with
1061      a basic surface.
1062
1063      Note! This protocol is deprecated and not intended for production use.
1064      For desktop-style user interfaces, use xdg_shell. Compositors and clients
1065      should not implement this interface.
1066    </description>
1067
1068    <enum name="error">
1069      <entry name="role" value="0" summary="given wl_surface has another role"/>
1070    </enum>
1071
1072    <request name="get_shell_surface">
1073      <description summary="create a shell surface from a surface">
1074	Create a shell surface for an existing surface. This gives
1075	the wl_surface the role of a shell surface. If the wl_surface
1076	already has another role, it raises a protocol error.
1077
1078	Only one shell surface can be associated with a given surface.
1079      </description>
1080      <arg name="id" type="new_id" interface="wl_shell_surface" summary="shell surface to create"/>
1081      <arg name="surface" type="object" interface="wl_surface" summary="surface to be given the shell surface role"/>
1082    </request>
1083  </interface>
1084
1085  <interface name="wl_shell_surface" version="1">
1086    <description summary="desktop-style metadata interface">
1087      An interface that may be implemented by a wl_surface, for
1088      implementations that provide a desktop-style user interface.
1089
1090      It provides requests to treat surfaces like toplevel, fullscreen
1091      or popup windows, move, resize or maximize them, associate
1092      metadata like title and class, etc.
1093
1094      On the server side the object is automatically destroyed when
1095      the related wl_surface is destroyed. On the client side,
1096      wl_shell_surface_destroy() must be called before destroying
1097      the wl_surface object.
1098    </description>
1099
1100    <request name="pong">
1101      <description summary="respond to a ping event">
1102	A client must respond to a ping event with a pong request or
1103	the client may be deemed unresponsive.
1104      </description>
1105      <arg name="serial" type="uint" summary="serial number of the ping event"/>
1106    </request>
1107
1108    <request name="move">
1109      <description summary="start an interactive move">
1110	Start a pointer-driven move of the surface.
1111
1112	This request must be used in response to a button press event.
1113	The server may ignore move requests depending on the state of
1114	the surface (e.g. fullscreen or maximized).
1115      </description>
1116      <arg name="seat" type="object" interface="wl_seat" summary="seat whose pointer is used"/>
1117      <arg name="serial" type="uint" summary="serial number of the implicit grab on the pointer"/>
1118    </request>
1119
1120    <enum name="resize" bitfield="true">
1121      <description summary="edge values for resizing">
1122	These values are used to indicate which edge of a surface
1123	is being dragged in a resize operation. The server may
1124	use this information to adapt its behavior, e.g. choose
1125	an appropriate cursor image.
1126      </description>
1127      <entry name="none" value="0" summary="no edge"/>
1128      <entry name="top" value="1" summary="top edge"/>
1129      <entry name="bottom" value="2" summary="bottom edge"/>
1130      <entry name="left" value="4" summary="left edge"/>
1131      <entry name="top_left" value="5" summary="top and left edges"/>
1132      <entry name="bottom_left" value="6" summary="bottom and left edges"/>
1133      <entry name="right" value="8" summary="right edge"/>
1134      <entry name="top_right" value="9" summary="top and right edges"/>
1135      <entry name="bottom_right" value="10" summary="bottom and right edges"/>
1136    </enum>
1137
1138    <request name="resize">
1139      <description summary="start an interactive resize">
1140	Start a pointer-driven resizing of the surface.
1141
1142	This request must be used in response to a button press event.
1143	The server may ignore resize requests depending on the state of
1144	the surface (e.g. fullscreen or maximized).
1145      </description>
1146      <arg name="seat" type="object" interface="wl_seat" summary="seat whose pointer is used"/>
1147      <arg name="serial" type="uint" summary="serial number of the implicit grab on the pointer"/>
1148      <arg name="edges" type="uint" enum="resize" summary="which edge or corner is being dragged"/>
1149    </request>
1150
1151    <request name="set_toplevel">
1152      <description summary="make the surface a toplevel surface">
1153	Map the surface as a toplevel surface.
1154
1155	A toplevel surface is not fullscreen, maximized or transient.
1156      </description>
1157    </request>
1158
1159    <enum name="transient" bitfield="true">
1160      <description summary="details of transient behaviour">
1161	These flags specify details of the expected behaviour
1162	of transient surfaces. Used in the set_transient request.
1163      </description>
1164      <entry name="inactive" value="0x1" summary="do not set keyboard focus"/>
1165    </enum>
1166
1167    <request name="set_transient">
1168      <description summary="make the surface a transient surface">
1169	Map the surface relative to an existing surface.
1170
1171	The x and y arguments specify the location of the upper left
1172	corner of the surface relative to the upper left corner of the
1173	parent surface, in surface-local coordinates.
1174
1175	The flags argument controls details of the transient behaviour.
1176      </description>
1177      <arg name="parent" type="object" interface="wl_surface" summary="parent surface"/>
1178      <arg name="x" type="int" summary="surface-local x coordinate"/>
1179      <arg name="y" type="int" summary="surface-local y coordinate"/>
1180      <arg name="flags" type="uint" enum="transient" summary="transient surface behavior"/>
1181    </request>
1182
1183    <enum name="fullscreen_method">
1184      <description summary="different method to set the surface fullscreen">
1185	Hints to indicate to the compositor how to deal with a conflict
1186	between the dimensions of the surface and the dimensions of the
1187	output. The compositor is free to ignore this parameter.
1188      </description>
1189      <entry name="default" value="0" summary="no preference, apply default policy"/>
1190      <entry name="scale" value="1" summary="scale, preserve the surface's aspect ratio and center on output"/>
1191      <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"/>
1192      <entry name="fill" value="3" summary="no upscaling, center on output and add black borders to compensate size mismatch"/>
1193    </enum>
1194
1195    <request name="set_fullscreen">
1196      <description summary="make the surface a fullscreen surface">
1197	Map the surface as a fullscreen surface.
1198
1199	If an output parameter is given then the surface will be made
1200	fullscreen on that output. If the client does not specify the
1201	output then the compositor will apply its policy - usually
1202	choosing the output on which the surface has the biggest surface
1203	area.
1204
1205	The client may specify a method to resolve a size conflict
1206	between the output size and the surface size - this is provided
1207	through the method parameter.
1208
1209	The framerate parameter is used only when the method is set
1210	to "driver", to indicate the preferred framerate. A value of 0
1211	indicates that the client does not care about framerate.  The
1212	framerate is specified in mHz, that is framerate of 60000 is 60Hz.
1213
1214	A method of "scale" or "driver" implies a scaling operation of
1215	the surface, either via a direct scaling operation or a change of
1216	the output mode. This will override any kind of output scaling, so
1217	that mapping a surface with a buffer size equal to the mode can
1218	fill the screen independent of buffer_scale.
1219
1220	A method of "fill" means we don't scale up the buffer, however
1221	any output scale is applied. This means that you may run into
1222	an edge case where the application maps a buffer with the same
1223	size of the output mode but buffer_scale 1 (thus making a
1224	surface larger than the output). In this case it is allowed to
1225	downscale the results to fit the screen.
1226
1227	The compositor must reply to this request with a configure event
1228	with the dimensions for the output on which the surface will
1229	be made fullscreen.
1230      </description>
1231      <arg name="method" type="uint" enum="fullscreen_method" summary="method for resolving size conflict"/>
1232      <arg name="framerate" type="uint" summary="framerate in mHz"/>
1233      <arg name="output" type="object" interface="wl_output" allow-null="true"
1234	   summary="output on which the surface is to be fullscreen"/>
1235    </request>
1236
1237    <request name="set_popup">
1238      <description summary="make the surface a popup surface">
1239	Map the surface as a popup.
1240
1241	A popup surface is a transient surface with an added pointer
1242	grab.
1243
1244	An existing implicit grab will be changed to owner-events mode,
1245	and the popup grab will continue after the implicit grab ends
1246	(i.e. releasing the mouse button does not cause the popup to
1247	be unmapped).
1248
1249	The popup grab continues until the window is destroyed or a
1250	mouse button is pressed in any other client's window. A click
1251	in any of the client's surfaces is reported as normal, however,
1252	clicks in other clients' surfaces will be discarded and trigger
1253	the callback.
1254
1255	The x and y arguments specify the location of the upper left
1256	corner of the surface relative to the upper left corner of the
1257	parent surface, in surface-local coordinates.
1258      </description>
1259      <arg name="seat" type="object" interface="wl_seat" summary="seat whose pointer is used"/>
1260      <arg name="serial" type="uint" summary="serial number of the implicit grab on the pointer"/>
1261      <arg name="parent" type="object" interface="wl_surface" summary="parent surface"/>
1262      <arg name="x" type="int" summary="surface-local x coordinate"/>
1263      <arg name="y" type="int" summary="surface-local y coordinate"/>
1264      <arg name="flags" type="uint" enum="transient" summary="transient surface behavior"/>
1265    </request>
1266
1267    <request name="set_maximized">
1268      <description summary="make the surface a maximized surface">
1269	Map the surface as a maximized surface.
1270
1271	If an output parameter is given then the surface will be
1272	maximized on that output. If the client does not specify the
1273	output then the compositor will apply its policy - usually
1274	choosing the output on which the surface has the biggest surface
1275	area.
1276
1277	The compositor will reply with a configure event telling
1278	the expected new surface size. The operation is completed
1279	on the next buffer attach to this surface.
1280
1281	A maximized surface typically fills the entire output it is
1282	bound to, except for desktop elements such as panels. This is
1283	the main difference between a maximized shell surface and a
1284	fullscreen shell surface.
1285
1286	The details depend on the compositor implementation.
1287      </description>
1288      <arg name="output" type="object" interface="wl_output" allow-null="true"
1289	   summary="output on which the surface is to be maximized"/>
1290    </request>
1291
1292    <request name="set_title">
1293      <description summary="set surface title">
1294	Set a short title for the surface.
1295
1296	This string may be used to identify the surface in a task bar,
1297	window list, or other user interface elements provided by the
1298	compositor.
1299
1300	The string must be encoded in UTF-8.
1301      </description>
1302      <arg name="title" type="string" summary="surface title"/>
1303    </request>
1304
1305    <request name="set_class">
1306      <description summary="set surface class">
1307	Set a class for the surface.
1308
1309	The surface class identifies the general class of applications
1310	to which the surface belongs. A common convention is to use the
1311	file name (or the full path if it is a non-standard location) of
1312	the application's .desktop file as the class.
1313      </description>
1314      <arg name="class_" type="string" summary="surface class"/>
1315    </request>
1316
1317    <event name="ping">
1318      <description summary="ping client">
1319	Ping a client to check if it is receiving events and sending
1320	requests. A client is expected to reply with a pong request.
1321      </description>
1322      <arg name="serial" type="uint" summary="serial number of the ping"/>
1323    </event>
1324
1325    <event name="configure">
1326      <description summary="suggest resize">
1327	The configure event asks the client to resize its surface.
1328
1329	The size is a hint, in the sense that the client is free to
1330	ignore it if it doesn't resize, pick a smaller size (to
1331	satisfy aspect ratio or resize in steps of NxM pixels).
1332
1333	The edges parameter provides a hint about how the surface
1334	was resized. The client may use this information to decide
1335	how to adjust its content to the new size (e.g. a scrolling
1336	area might adjust its content position to leave the viewable
1337	content unmoved).
1338
1339	The client is free to dismiss all but the last configure
1340	event it received.
1341
1342	The width and height arguments specify the size of the window
1343	in surface-local coordinates.
1344      </description>
1345      <arg name="edges" type="uint" enum="resize" summary="how the surface was resized"/>
1346      <arg name="width" type="int" summary="new width of the surface"/>
1347      <arg name="height" type="int" summary="new height of the surface"/>
1348    </event>
1349
1350    <event name="popup_done">
1351      <description summary="popup interaction is done">
1352	The popup_done event is sent out when a popup grab is broken,
1353	that is, when the user clicks a surface that doesn't belong
1354	to the client owning the popup surface.
1355      </description>
1356    </event>
1357  </interface>
1358
1359  <interface name="wl_surface" version="6">
1360    <description summary="an onscreen surface">
1361      A surface is a rectangular area that may be displayed on zero
1362      or more outputs, and shown any number of times at the compositor's
1363      discretion. They can present wl_buffers, receive user input, and
1364      define a local coordinate system.
1365
1366      The size of a surface (and relative positions on it) is described
1367      in surface-local coordinates, which may differ from the buffer
1368      coordinates of the pixel content, in case a buffer_transform
1369      or a buffer_scale is used.
1370
1371      A surface without a "role" is fairly useless: a compositor does
1372      not know where, when or how to present it. The role is the
1373      purpose of a wl_surface. Examples of roles are a cursor for a
1374      pointer (as set by wl_pointer.set_cursor), a drag icon
1375      (wl_data_device.start_drag), a sub-surface
1376      (wl_subcompositor.get_subsurface), and a window as defined by a
1377      shell protocol (e.g. wl_shell.get_shell_surface).
1378
1379      A surface can have only one role at a time. Initially a
1380      wl_surface does not have a role. Once a wl_surface is given a
1381      role, it is set permanently for the whole lifetime of the
1382      wl_surface object. Giving the current role again is allowed,
1383      unless explicitly forbidden by the relevant interface
1384      specification.
1385
1386      Surface roles are given by requests in other interfaces such as
1387      wl_pointer.set_cursor. The request should explicitly mention
1388      that this request gives a role to a wl_surface. Often, this
1389      request also creates a new protocol object that represents the
1390      role and adds additional functionality to wl_surface. When a
1391      client wants to destroy a wl_surface, they must destroy this role
1392      object before the wl_surface, otherwise a defunct_role_object error is
1393      sent.
1394
1395      Destroying the role object does not remove the role from the
1396      wl_surface, but it may stop the wl_surface from "playing the role".
1397      For instance, if a wl_subsurface object is destroyed, the wl_surface
1398      it was created for will be unmapped and forget its position and
1399      z-order. It is allowed to create a wl_subsurface for the same
1400      wl_surface again, but it is not allowed to use the wl_surface as
1401      a cursor (cursor is a different role than sub-surface, and role
1402      switching is not allowed).
1403    </description>
1404
1405    <enum name="error">
1406      <description summary="wl_surface error values">
1407	These errors can be emitted in response to wl_surface requests.
1408      </description>
1409      <entry name="invalid_scale" value="0" summary="buffer scale value is invalid"/>
1410      <entry name="invalid_transform" value="1" summary="buffer transform value is invalid"/>
1411      <entry name="invalid_size" value="2" summary="buffer size is invalid"/>
1412      <entry name="invalid_offset" value="3" summary="buffer offset is invalid"/>
1413      <entry name="defunct_role_object" value="4"
1414             summary="surface was destroyed before its role object"/>
1415    </enum>
1416
1417    <request name="destroy" type="destructor">
1418      <description summary="delete surface">
1419	Deletes the surface and invalidates its object ID.
1420      </description>
1421    </request>
1422
1423    <request name="attach">
1424      <description summary="set the surface contents">
1425	Set a buffer as the content of this surface.
1426
1427	The new size of the surface is calculated based on the buffer
1428	size transformed by the inverse buffer_transform and the
1429	inverse buffer_scale. This means that at commit time the supplied
1430	buffer size must be an integer multiple of the buffer_scale. If
1431	that's not the case, an invalid_size error is sent.
1432
1433	The x and y arguments specify the location of the new pending
1434	buffer's upper left corner, relative to the current buffer's upper
1435	left corner, in surface-local coordinates. In other words, the
1436	x and y, combined with the new surface size define in which
1437	directions the surface's size changes. Setting anything other than 0
1438	as x and y arguments is discouraged, and should instead be replaced
1439	with using the separate wl_surface.offset request.
1440
1441	When the bound wl_surface version is 5 or higher, passing any
1442	non-zero x or y is a protocol violation, and will result in an
1443        'invalid_offset' error being raised. The x and y arguments are ignored
1444        and do not change the pending state. To achieve equivalent semantics,
1445        use wl_surface.offset.
1446
1447	Surface contents are double-buffered state, see wl_surface.commit.
1448
1449	The initial surface contents are void; there is no content.
1450	wl_surface.attach assigns the given wl_buffer as the pending
1451	wl_buffer. wl_surface.commit makes the pending wl_buffer the new
1452	surface contents, and the size of the surface becomes the size
1453	calculated from the wl_buffer, as described above. After commit,
1454	there is no pending buffer until the next attach.
1455
1456	Committing a pending wl_buffer allows the compositor to read the
1457	pixels in the wl_buffer. The compositor may access the pixels at
1458	any time after the wl_surface.commit request. When the compositor
1459	will not access the pixels anymore, it will send the
1460	wl_buffer.release event. Only after receiving wl_buffer.release,
1461	the client may reuse the wl_buffer. A wl_buffer that has been
1462	attached and then replaced by another attach instead of committed
1463	will not receive a release event, and is not used by the
1464	compositor.
1465
1466	If a pending wl_buffer has been committed to more than one wl_surface,
1467	the delivery of wl_buffer.release events becomes undefined. A well
1468	behaved client should not rely on wl_buffer.release events in this
1469	case. Alternatively, a client could create multiple wl_buffer objects
1470	from the same backing storage or use wp_linux_buffer_release.
1471
1472	Destroying the wl_buffer after wl_buffer.release does not change
1473	the surface contents. Destroying the wl_buffer before wl_buffer.release
1474	is allowed as long as the underlying buffer storage isn't re-used (this
1475	can happen e.g. on client process termination). However, if the client
1476	destroys the wl_buffer before receiving the wl_buffer.release event and
1477	mutates the underlying buffer storage, the surface contents become
1478	undefined immediately.
1479
1480	If wl_surface.attach is sent with a NULL wl_buffer, the
1481	following wl_surface.commit will remove the surface content.
1482      </description>
1483      <arg name="buffer" type="object" interface="wl_buffer" allow-null="true"
1484	   summary="buffer of surface contents"/>
1485      <arg name="x" type="int" summary="surface-local x coordinate"/>
1486      <arg name="y" type="int" summary="surface-local y coordinate"/>
1487    </request>
1488
1489    <request name="damage">
1490      <description summary="mark part of the surface damaged">
1491	This request is used to describe the regions where the pending
1492	buffer is different from the current surface contents, and where
1493	the surface therefore needs to be repainted. The compositor
1494	ignores the parts of the damage that fall outside of the surface.
1495
1496	Damage is double-buffered state, see wl_surface.commit.
1497
1498	The damage rectangle is specified in surface-local coordinates,
1499	where x and y specify the upper left corner of the damage rectangle.
1500
1501	The initial value for pending damage is empty: no damage.
1502	wl_surface.damage adds pending damage: the new pending damage
1503	is the union of old pending damage and the given rectangle.
1504
1505	wl_surface.commit assigns pending damage as the current damage,
1506	and clears pending damage. The server will clear the current
1507	damage as it repaints the surface.
1508
1509	Note! New clients should not use this request. Instead damage can be
1510	posted with wl_surface.damage_buffer which uses buffer coordinates
1511	instead of surface coordinates.
1512      </description>
1513      <arg name="x" type="int" summary="surface-local x coordinate"/>
1514      <arg name="y" type="int" summary="surface-local y coordinate"/>
1515      <arg name="width" type="int" summary="width of damage rectangle"/>
1516      <arg name="height" type="int" summary="height of damage rectangle"/>
1517    </request>
1518
1519    <request name="frame">
1520      <description summary="request a frame throttling hint">
1521	Request a notification when it is a good time to start drawing a new
1522	frame, by creating a frame callback. This is useful for throttling
1523	redrawing operations, and driving animations.
1524
1525	When a client is animating on a wl_surface, it can use the 'frame'
1526	request to get notified when it is a good time to draw and commit the
1527	next frame of animation. If the client commits an update earlier than
1528	that, it is likely that some updates will not make it to the display,
1529	and the client is wasting resources by drawing too often.
1530
1531	The frame request will take effect on the next wl_surface.commit.
1532	The notification will only be posted for one frame unless
1533	requested again. For a wl_surface, the notifications are posted in
1534	the order the frame requests were committed.
1535
1536	The server must send the notifications so that a client
1537	will not send excessive updates, while still allowing
1538	the highest possible update rate for clients that wait for the reply
1539	before drawing again. The server should give some time for the client
1540	to draw and commit after sending the frame callback events to let it
1541	hit the next output refresh.
1542
1543	A server should avoid signaling the frame callbacks if the
1544	surface is not visible in any way, e.g. the surface is off-screen,
1545	or completely obscured by other opaque surfaces.
1546
1547	The object returned by this request will be destroyed by the
1548	compositor after the callback is fired and as such the client must not
1549	attempt to use it after that point.
1550
1551	The callback_data passed in the callback is the current time, in
1552	milliseconds, with an undefined base.
1553      </description>
1554      <arg name="callback" type="new_id" interface="wl_callback" summary="callback object for the frame request"/>
1555    </request>
1556
1557    <request name="set_opaque_region">
1558      <description summary="set opaque region">
1559	This request sets the region of the surface that contains
1560	opaque content.
1561
1562	The opaque region is an optimization hint for the compositor
1563	that lets it optimize the redrawing of content behind opaque
1564	regions.  Setting an opaque region is not required for correct
1565	behaviour, but marking transparent content as opaque will result
1566	in repaint artifacts.
1567
1568	The opaque region is specified in surface-local coordinates.
1569
1570	The compositor ignores the parts of the opaque region that fall
1571	outside of the surface.
1572
1573	Opaque region is double-buffered state, see wl_surface.commit.
1574
1575	wl_surface.set_opaque_region changes the pending opaque region.
1576	wl_surface.commit copies the pending region to the current region.
1577	Otherwise, the pending and current regions are never changed.
1578
1579	The initial value for an opaque region is empty. Setting the pending
1580	opaque region has copy semantics, and the wl_region object can be
1581	destroyed immediately. A NULL wl_region causes the pending opaque
1582	region to be set to empty.
1583      </description>
1584      <arg name="region" type="object" interface="wl_region" allow-null="true"
1585	   summary="opaque region of the surface"/>
1586    </request>
1587
1588    <request name="set_input_region">
1589      <description summary="set input region">
1590	This request sets the region of the surface that can receive
1591	pointer and touch events.
1592
1593	Input events happening outside of this region will try the next
1594	surface in the server surface stack. The compositor ignores the
1595	parts of the input region that fall outside of the surface.
1596
1597	The input region is specified in surface-local coordinates.
1598
1599	Input region is double-buffered state, see wl_surface.commit.
1600
1601	wl_surface.set_input_region changes the pending input region.
1602	wl_surface.commit copies the pending region to the current region.
1603	Otherwise the pending and current regions are never changed,
1604	except cursor and icon surfaces are special cases, see
1605	wl_pointer.set_cursor and wl_data_device.start_drag.
1606
1607	The initial value for an input region is infinite. That means the
1608	whole surface will accept input. Setting the pending input region
1609	has copy semantics, and the wl_region object can be destroyed
1610	immediately. A NULL wl_region causes the input region to be set
1611	to infinite.
1612      </description>
1613      <arg name="region" type="object" interface="wl_region" allow-null="true"
1614	   summary="input region of the surface"/>
1615    </request>
1616
1617    <request name="commit">
1618      <description summary="commit pending surface state">
1619	Surface state (input, opaque, and damage regions, attached buffers,
1620	etc.) is double-buffered. Protocol requests modify the pending state,
1621	as opposed to the current state in use by the compositor. A commit
1622	request atomically applies all pending state, replacing the current
1623	state. After commit, the new pending state is as documented for each
1624	related request.
1625
1626	On commit, a pending wl_buffer is applied first, and all other state
1627	second. This means that all coordinates in double-buffered state are
1628	relative to the new wl_buffer coming into use, except for
1629	wl_surface.attach itself. If there is no pending wl_buffer, the
1630	coordinates are relative to the current surface contents.
1631
1632	All requests that need a commit to become effective are documented
1633	to affect double-buffered state.
1634
1635	Other interfaces may add further double-buffered surface state.
1636      </description>
1637    </request>
1638
1639    <event name="enter">
1640      <description summary="surface enters an output">
1641	This is emitted whenever a surface's creation, movement, or resizing
1642	results in some part of it being within the scanout region of an
1643	output.
1644
1645	Note that a surface may be overlapping with zero or more outputs.
1646      </description>
1647      <arg name="output" type="object" interface="wl_output" summary="output entered by the surface"/>
1648    </event>
1649
1650    <event name="leave">
1651      <description summary="surface leaves an output">
1652	This is emitted whenever a surface's creation, movement, or resizing
1653	results in it no longer having any part of it within the scanout region
1654	of an output.
1655
1656	Clients should not use the number of outputs the surface is on for frame
1657	throttling purposes. The surface might be hidden even if no leave event
1658	has been sent, and the compositor might expect new surface content
1659	updates even if no enter event has been sent. The frame event should be
1660	used instead.
1661      </description>
1662      <arg name="output" type="object" interface="wl_output" summary="output left by the surface"/>
1663    </event>
1664
1665    <!-- Version 2 additions -->
1666
1667    <request name="set_buffer_transform" since="2">
1668      <description summary="sets the buffer transformation">
1669	This request sets an optional transformation on how the compositor
1670	interprets the contents of the buffer attached to the surface. The
1671	accepted values for the transform parameter are the values for
1672	wl_output.transform.
1673
1674	Buffer transform is double-buffered state, see wl_surface.commit.
1675
1676	A newly created surface has its buffer transformation set to normal.
1677
1678	wl_surface.set_buffer_transform changes the pending buffer
1679	transformation. wl_surface.commit copies the pending buffer
1680	transformation to the current one. Otherwise, the pending and current
1681	values are never changed.
1682
1683	The purpose of this request is to allow clients to render content
1684	according to the output transform, thus permitting the compositor to
1685	use certain optimizations even if the display is rotated. Using
1686	hardware overlays and scanning out a client buffer for fullscreen
1687	surfaces are examples of such optimizations. Those optimizations are
1688	highly dependent on the compositor implementation, so the use of this
1689	request should be considered on a case-by-case basis.
1690
1691	Note that if the transform value includes 90 or 270 degree rotation,
1692	the width of the buffer will become the surface height and the height
1693	of the buffer will become the surface width.
1694
1695	If transform is not one of the values from the
1696	wl_output.transform enum the invalid_transform protocol error
1697	is raised.
1698      </description>
1699      <arg name="transform" type="int" enum="wl_output.transform"
1700	   summary="transform for interpreting buffer contents"/>
1701    </request>
1702
1703    <!-- Version 3 additions -->
1704
1705    <request name="set_buffer_scale" since="3">
1706      <description summary="sets the buffer scaling factor">
1707	This request sets an optional scaling factor on how the compositor
1708	interprets the contents of the buffer attached to the window.
1709
1710	Buffer scale is double-buffered state, see wl_surface.commit.
1711
1712	A newly created surface has its buffer scale set to 1.
1713
1714	wl_surface.set_buffer_scale changes the pending buffer scale.
1715	wl_surface.commit copies the pending buffer scale to the current one.
1716	Otherwise, the pending and current values are never changed.
1717
1718	The purpose of this request is to allow clients to supply higher
1719	resolution buffer data for use on high resolution outputs. It is
1720	intended that you pick the same buffer scale as the scale of the
1721	output that the surface is displayed on. This means the compositor
1722	can avoid scaling when rendering the surface on that output.
1723
1724	Note that if the scale is larger than 1, then you have to attach
1725	a buffer that is larger (by a factor of scale in each dimension)
1726	than the desired surface size.
1727
1728	If scale is not positive the invalid_scale protocol error is
1729	raised.
1730      </description>
1731      <arg name="scale" type="int"
1732	   summary="positive scale for interpreting buffer contents"/>
1733    </request>
1734
1735    <!-- Version 4 additions -->
1736    <request name="damage_buffer" since="4">
1737      <description summary="mark part of the surface damaged using buffer coordinates">
1738	This request is used to describe the regions where the pending
1739	buffer is different from the current surface contents, and where
1740	the surface therefore needs to be repainted. The compositor
1741	ignores the parts of the damage that fall outside of the surface.
1742
1743	Damage is double-buffered state, see wl_surface.commit.
1744
1745	The damage rectangle is specified in buffer coordinates,
1746	where x and y specify the upper left corner of the damage rectangle.
1747
1748	The initial value for pending damage is empty: no damage.
1749	wl_surface.damage_buffer adds pending damage: the new pending
1750	damage is the union of old pending damage and the given rectangle.
1751
1752	wl_surface.commit assigns pending damage as the current damage,
1753	and clears pending damage. The server will clear the current
1754	damage as it repaints the surface.
1755
1756	This request differs from wl_surface.damage in only one way - it
1757	takes damage in buffer coordinates instead of surface-local
1758	coordinates. While this generally is more intuitive than surface
1759	coordinates, it is especially desirable when using wp_viewport
1760	or when a drawing library (like EGL) is unaware of buffer scale
1761	and buffer transform.
1762
1763	Note: Because buffer transformation changes and damage requests may
1764	be interleaved in the protocol stream, it is impossible to determine
1765	the actual mapping between surface and buffer damage until
1766	wl_surface.commit time. Therefore, compositors wishing to take both
1767	kinds of damage into account will have to accumulate damage from the
1768	two requests separately and only transform from one to the other
1769	after receiving the wl_surface.commit.
1770      </description>
1771      <arg name="x" type="int" summary="buffer-local x coordinate"/>
1772      <arg name="y" type="int" summary="buffer-local y coordinate"/>
1773      <arg name="width" type="int" summary="width of damage rectangle"/>
1774      <arg name="height" type="int" summary="height of damage rectangle"/>
1775    </request>
1776
1777    <!-- Version 5 additions -->
1778
1779    <request name="offset" since="5">
1780      <description summary="set the surface contents offset">
1781	The x and y arguments specify the location of the new pending
1782	buffer's upper left corner, relative to the current buffer's upper
1783	left corner, in surface-local coordinates. In other words, the
1784	x and y, combined with the new surface size define in which
1785	directions the surface's size changes.
1786
1787	Surface location offset is double-buffered state, see
1788	wl_surface.commit.
1789
1790	This request is semantically equivalent to and the replaces the x and y
1791	arguments in the wl_surface.attach request in wl_surface versions prior
1792	to 5. See wl_surface.attach for details.
1793      </description>
1794      <arg name="x" type="int" summary="surface-local x coordinate"/>
1795      <arg name="y" type="int" summary="surface-local y coordinate"/>
1796    </request>
1797
1798    <!-- Version 6 additions -->
1799
1800    <event name="preferred_buffer_scale" since="6">
1801      <description summary="preferred buffer scale for the surface">
1802	This event indicates the preferred buffer scale for this surface. It is
1803	sent whenever the compositor's preference changes.
1804
1805	It is intended that scaling aware clients use this event to scale their
1806	content and use wl_surface.set_buffer_scale to indicate the scale they
1807	have rendered with. This allows clients to supply a higher detail
1808	buffer.
1809      </description>
1810      <arg name="factor" type="int" summary="preferred scaling factor"/>
1811    </event>
1812
1813    <event name="preferred_buffer_transform" since="6">
1814      <description summary="preferred buffer transform for the surface">
1815	This event indicates the preferred buffer transform for this surface.
1816	It is sent whenever the compositor's preference changes.
1817
1818	It is intended that transform aware clients use this event to apply the
1819	transform to their content and use wl_surface.set_buffer_transform to
1820	indicate the transform they have rendered with.
1821      </description>
1822      <arg name="transform" type="uint" enum="wl_output.transform"
1823	   summary="preferred transform"/>
1824    </event>
1825   </interface>
1826
1827  <interface name="wl_seat" version="9">
1828    <description summary="group of input devices">
1829      A seat is a group of keyboards, pointer and touch devices. This
1830      object is published as a global during start up, or when such a
1831      device is hot plugged.  A seat typically has a pointer and
1832      maintains a keyboard focus and a pointer focus.
1833    </description>
1834
1835    <enum name="capability" bitfield="true">
1836      <description summary="seat capability bitmask">
1837	This is a bitmask of capabilities this seat has; if a member is
1838	set, then it is present on the seat.
1839      </description>
1840      <entry name="pointer" value="1" summary="the seat has pointer devices"/>
1841      <entry name="keyboard" value="2" summary="the seat has one or more keyboards"/>
1842      <entry name="touch" value="4" summary="the seat has touch devices"/>
1843    </enum>
1844
1845    <enum name="error">
1846      <description summary="wl_seat error values">
1847	These errors can be emitted in response to wl_seat requests.
1848      </description>
1849      <entry name="missing_capability" value="0"
1850	     summary="get_pointer, get_keyboard or get_touch called on seat without the matching capability"/>
1851    </enum>
1852
1853    <event name="capabilities">
1854      <description summary="seat capabilities changed">
1855	This is emitted whenever a seat gains or loses the pointer,
1856	keyboard or touch capabilities.  The argument is a capability
1857	enum containing the complete set of capabilities this seat has.
1858
1859	When the pointer capability is added, a client may create a
1860	wl_pointer object using the wl_seat.get_pointer request. This object
1861	will receive pointer events until the capability is removed in the
1862	future.
1863
1864	When the pointer capability is removed, a client should destroy the
1865	wl_pointer objects associated with the seat where the capability was
1866	removed, using the wl_pointer.release request. No further pointer
1867	events will be received on these objects.
1868
1869	In some compositors, if a seat regains the pointer capability and a
1870	client has a previously obtained wl_pointer object of version 4 or
1871	less, that object may start sending pointer events again. This
1872	behavior is considered a misinterpretation of the intended behavior
1873	and must not be relied upon by the client. wl_pointer objects of
1874	version 5 or later must not send events if created before the most
1875	recent event notifying the client of an added pointer capability.
1876
1877	The above behavior also applies to wl_keyboard and wl_touch with the
1878	keyboard and touch capabilities, respectively.
1879      </description>
1880      <arg name="capabilities" type="uint" enum="capability" summary="capabilities of the seat"/>
1881    </event>
1882
1883    <request name="get_pointer">
1884      <description summary="return pointer object">
1885	The ID provided will be initialized to the wl_pointer interface
1886	for this seat.
1887
1888	This request only takes effect if the seat has the pointer
1889	capability, or has had the pointer capability in the past.
1890	It is a protocol violation to issue this request on a seat that has
1891	never had the pointer capability. The missing_capability error will
1892	be sent in this case.
1893      </description>
1894      <arg name="id" type="new_id" interface="wl_pointer" summary="seat pointer"/>
1895    </request>
1896
1897    <request name="get_keyboard">
1898      <description summary="return keyboard object">
1899	The ID provided will be initialized to the wl_keyboard interface
1900	for this seat.
1901
1902	This request only takes effect if the seat has the keyboard
1903	capability, or has had the keyboard capability in the past.
1904	It is a protocol violation to issue this request on a seat that has
1905	never had the keyboard capability. The missing_capability error will
1906	be sent in this case.
1907      </description>
1908      <arg name="id" type="new_id" interface="wl_keyboard" summary="seat keyboard"/>
1909    </request>
1910
1911    <request name="get_touch">
1912      <description summary="return touch object">
1913	The ID provided will be initialized to the wl_touch interface
1914	for this seat.
1915
1916	This request only takes effect if the seat has the touch
1917	capability, or has had the touch capability in the past.
1918	It is a protocol violation to issue this request on a seat that has
1919	never had the touch capability. The missing_capability error will
1920	be sent in this case.
1921      </description>
1922      <arg name="id" type="new_id" interface="wl_touch" summary="seat touch interface"/>
1923    </request>
1924
1925    <!-- Version 2 additions -->
1926
1927    <event name="name" since="2">
1928      <description summary="unique identifier for this seat">
1929	In a multi-seat configuration the seat name can be used by clients to
1930	help identify which physical devices the seat represents.
1931
1932	The seat name is a UTF-8 string with no convention defined for its
1933	contents. Each name is unique among all wl_seat globals. The name is
1934	only guaranteed to be unique for the current compositor instance.
1935
1936	The same seat names are used for all clients. Thus, the name can be
1937	shared across processes to refer to a specific wl_seat global.
1938
1939	The name event is sent after binding to the seat global. This event is
1940	only sent once per seat object, and the name does not change over the
1941	lifetime of the wl_seat global.
1942
1943	Compositors may re-use the same seat name if the wl_seat global is
1944	destroyed and re-created later.
1945      </description>
1946      <arg name="name" type="string" summary="seat identifier"/>
1947    </event>
1948
1949    <!-- Version 5 additions -->
1950
1951    <request name="release" type="destructor" since="5">
1952      <description summary="release the seat object">
1953	Using this request a client can tell the server that it is not going to
1954	use the seat object anymore.
1955      </description>
1956    </request>
1957
1958  </interface>
1959
1960  <interface name="wl_pointer" version="9">
1961    <description summary="pointer input device">
1962      The wl_pointer interface represents one or more input devices,
1963      such as mice, which control the pointer location and pointer_focus
1964      of a seat.
1965
1966      The wl_pointer interface generates motion, enter and leave
1967      events for the surfaces that the pointer is located over,
1968      and button and axis events for button presses, button releases
1969      and scrolling.
1970    </description>
1971
1972    <enum name="error">
1973      <entry name="role" value="0" summary="given wl_surface has another role"/>
1974    </enum>
1975
1976    <request name="set_cursor">
1977      <description summary="set the pointer surface">
1978	Set the pointer surface, i.e., the surface that contains the
1979	pointer image (cursor). This request gives the surface the role
1980	of a cursor. If the surface already has another role, it raises
1981	a protocol error.
1982
1983	The cursor actually changes only if the pointer
1984	focus for this device is one of the requesting client's surfaces
1985	or the surface parameter is the current pointer surface. If
1986	there was a previous surface set with this request it is
1987	replaced. If surface is NULL, the pointer image is hidden.
1988
1989	The parameters hotspot_x and hotspot_y define the position of
1990	the pointer surface relative to the pointer location. Its
1991	top-left corner is always at (x, y) - (hotspot_x, hotspot_y),
1992	where (x, y) are the coordinates of the pointer location, in
1993	surface-local coordinates.
1994
1995	On surface.attach requests to the pointer surface, hotspot_x
1996	and hotspot_y are decremented by the x and y parameters
1997	passed to the request. Attach must be confirmed by
1998	wl_surface.commit as usual.
1999
2000	The hotspot can also be updated by passing the currently set
2001	pointer surface to this request with new values for hotspot_x
2002	and hotspot_y.
2003
2004	The input region is ignored for wl_surfaces with the role of
2005	a cursor. When the use as a cursor ends, the wl_surface is
2006	unmapped.
2007
2008	The serial parameter must match the latest wl_pointer.enter
2009	serial number sent to the client. Otherwise the request will be
2010	ignored.
2011      </description>
2012      <arg name="serial" type="uint" summary="serial number of the enter event"/>
2013      <arg name="surface" type="object" interface="wl_surface" allow-null="true"
2014	   summary="pointer surface"/>
2015      <arg name="hotspot_x" type="int" summary="surface-local x coordinate"/>
2016      <arg name="hotspot_y" type="int" summary="surface-local y coordinate"/>
2017    </request>
2018
2019    <event name="enter">
2020      <description summary="enter event">
2021	Notification that this seat's pointer is focused on a certain
2022	surface.
2023
2024	When a seat's focus enters a surface, the pointer image
2025	is undefined and a client should respond to this event by setting
2026	an appropriate pointer image with the set_cursor request.
2027      </description>
2028      <arg name="serial" type="uint" summary="serial number of the enter event"/>
2029      <arg name="surface" type="object" interface="wl_surface" summary="surface entered by the pointer"/>
2030      <arg name="surface_x" type="fixed" summary="surface-local x coordinate"/>
2031      <arg name="surface_y" type="fixed" summary="surface-local y coordinate"/>
2032    </event>
2033
2034    <event name="leave">
2035      <description summary="leave event">
2036	Notification that this seat's pointer is no longer focused on
2037	a certain surface.
2038
2039	The leave notification is sent before the enter notification
2040	for the new focus.
2041      </description>
2042      <arg name="serial" type="uint" summary="serial number of the leave event"/>
2043      <arg name="surface" type="object" interface="wl_surface" summary="surface left by the pointer"/>
2044    </event>
2045
2046    <event name="motion">
2047      <description summary="pointer motion event">
2048	Notification of pointer location change. The arguments
2049	surface_x and surface_y are the location relative to the
2050	focused surface.
2051      </description>
2052      <arg name="time" type="uint" summary="timestamp with millisecond granularity"/>
2053      <arg name="surface_x" type="fixed" summary="surface-local x coordinate"/>
2054      <arg name="surface_y" type="fixed" summary="surface-local y coordinate"/>
2055    </event>
2056
2057    <enum name="button_state">
2058      <description summary="physical button state">
2059	Describes the physical state of a button that produced the button
2060	event.
2061      </description>
2062      <entry name="released" value="0" summary="the button is not pressed"/>
2063      <entry name="pressed" value="1" summary="the button is pressed"/>
2064    </enum>
2065
2066    <event name="button">
2067      <description summary="pointer button event">
2068	Mouse button click and release notifications.
2069
2070	The location of the click is given by the last motion or
2071	enter event.
2072	The time argument is a timestamp with millisecond
2073	granularity, with an undefined base.
2074
2075	The button is a button code as defined in the Linux kernel's
2076	linux/input-event-codes.h header file, e.g. BTN_LEFT.
2077
2078	Any 16-bit button code value is reserved for future additions to the
2079	kernel's event code list. All other button codes above 0xFFFF are
2080	currently undefined but may be used in future versions of this
2081	protocol.
2082      </description>
2083      <arg name="serial" type="uint" summary="serial number of the button event"/>
2084      <arg name="time" type="uint" summary="timestamp with millisecond granularity"/>
2085      <arg name="button" type="uint" summary="button that produced the event"/>
2086      <arg name="state" type="uint" enum="button_state" summary="physical state of the button"/>
2087    </event>
2088
2089    <enum name="axis">
2090      <description summary="axis types">
2091	Describes the axis types of scroll events.
2092      </description>
2093      <entry name="vertical_scroll" value="0" summary="vertical axis"/>
2094      <entry name="horizontal_scroll" value="1" summary="horizontal axis"/>
2095    </enum>
2096
2097    <event name="axis">
2098      <description summary="axis event">
2099	Scroll and other axis notifications.
2100
2101	For scroll events (vertical and horizontal scroll axes), the
2102	value parameter is the length of a vector along the specified
2103	axis in a coordinate space identical to those of motion events,
2104	representing a relative movement along the specified axis.
2105
2106	For devices that support movements non-parallel to axes multiple
2107	axis events will be emitted.
2108
2109	When applicable, for example for touch pads, the server can
2110	choose to emit scroll events where the motion vector is
2111	equivalent to a motion event vector.
2112
2113	When applicable, a client can transform its content relative to the
2114	scroll distance.
2115      </description>
2116      <arg name="time" type="uint" summary="timestamp with millisecond granularity"/>
2117      <arg name="axis" type="uint" enum="axis" summary="axis type"/>
2118      <arg name="value" type="fixed" summary="length of vector in surface-local coordinate space"/>
2119    </event>
2120
2121    <!-- Version 3 additions -->
2122
2123    <request name="release" type="destructor" since="3">
2124      <description summary="release the pointer object">
2125	Using this request a client can tell the server that it is not going to
2126	use the pointer object anymore.
2127
2128	This request destroys the pointer proxy object, so clients must not call
2129	wl_pointer_destroy() after using this request.
2130      </description>
2131    </request>
2132
2133    <!-- Version 5 additions -->
2134
2135    <event name="frame" since="5">
2136      <description summary="end of a pointer event sequence">
2137	Indicates the end of a set of events that logically belong together.
2138	A client is expected to accumulate the data in all events within the
2139	frame before proceeding.
2140
2141	All wl_pointer events before a wl_pointer.frame event belong
2142	logically together. For example, in a diagonal scroll motion the
2143	compositor will send an optional wl_pointer.axis_source event, two
2144	wl_pointer.axis events (horizontal and vertical) and finally a
2145	wl_pointer.frame event. The client may use this information to
2146	calculate a diagonal vector for scrolling.
2147
2148	When multiple wl_pointer.axis events occur within the same frame,
2149	the motion vector is the combined motion of all events.
2150	When a wl_pointer.axis and a wl_pointer.axis_stop event occur within
2151	the same frame, this indicates that axis movement in one axis has
2152	stopped but continues in the other axis.
2153	When multiple wl_pointer.axis_stop events occur within the same
2154	frame, this indicates that these axes stopped in the same instance.
2155
2156	A wl_pointer.frame event is sent for every logical event group,
2157	even if the group only contains a single wl_pointer event.
2158	Specifically, a client may get a sequence: motion, frame, button,
2159	frame, axis, frame, axis_stop, frame.
2160
2161	The wl_pointer.enter and wl_pointer.leave events are logical events
2162	generated by the compositor and not the hardware. These events are
2163	also grouped by a wl_pointer.frame. When a pointer moves from one
2164	surface to another, a compositor should group the
2165	wl_pointer.leave event within the same wl_pointer.frame.
2166	However, a client must not rely on wl_pointer.leave and
2167	wl_pointer.enter being in the same wl_pointer.frame.
2168	Compositor-specific policies may require the wl_pointer.leave and
2169	wl_pointer.enter event being split across multiple wl_pointer.frame
2170	groups.
2171      </description>
2172    </event>
2173
2174    <enum name="axis_source">
2175      <description summary="axis source types">
2176	Describes the source types for axis events. This indicates to the
2177	client how an axis event was physically generated; a client may
2178	adjust the user interface accordingly. For example, scroll events
2179	from a "finger" source may be in a smooth coordinate space with
2180	kinetic scrolling whereas a "wheel" source may be in discrete steps
2181	of a number of lines.
2182
2183	The "continuous" axis source is a device generating events in a
2184	continuous coordinate space, but using something other than a
2185	finger. One example for this source is button-based scrolling where
2186	the vertical motion of a device is converted to scroll events while
2187	a button is held down.
2188
2189	The "wheel tilt" axis source indicates that the actual device is a
2190	wheel but the scroll event is not caused by a rotation but a
2191	(usually sideways) tilt of the wheel.
2192      </description>
2193      <entry name="wheel" value="0" summary="a physical wheel rotation" />
2194      <entry name="finger" value="1" summary="finger on a touch surface" />
2195      <entry name="continuous" value="2" summary="continuous coordinate space"/>
2196      <entry name="wheel_tilt" value="3" summary="a physical wheel tilt" since="6"/>
2197    </enum>
2198
2199    <event name="axis_source" since="5">
2200      <description summary="axis source event">
2201	Source information for scroll and other axes.
2202
2203	This event does not occur on its own. It is sent before a
2204	wl_pointer.frame event and carries the source information for
2205	all events within that frame.
2206
2207	The source specifies how this event was generated. If the source is
2208	wl_pointer.axis_source.finger, a wl_pointer.axis_stop event will be
2209	sent when the user lifts the finger off the device.
2210
2211	If the source is wl_pointer.axis_source.wheel,
2212	wl_pointer.axis_source.wheel_tilt or
2213	wl_pointer.axis_source.continuous, a wl_pointer.axis_stop event may
2214	or may not be sent. Whether a compositor sends an axis_stop event
2215	for these sources is hardware-specific and implementation-dependent;
2216	clients must not rely on receiving an axis_stop event for these
2217	scroll sources and should treat scroll sequences from these scroll
2218	sources as unterminated by default.
2219
2220	This event is optional. If the source is unknown for a particular
2221	axis event sequence, no event is sent.
2222	Only one wl_pointer.axis_source event is permitted per frame.
2223
2224	The order of wl_pointer.axis_discrete and wl_pointer.axis_source is
2225	not guaranteed.
2226      </description>
2227      <arg name="axis_source" type="uint" enum="axis_source" summary="source of the axis event"/>
2228    </event>
2229
2230    <event name="axis_stop" since="5">
2231      <description summary="axis stop event">
2232	Stop notification for scroll and other axes.
2233
2234	For some wl_pointer.axis_source types, a wl_pointer.axis_stop event
2235	is sent to notify a client that the axis sequence has terminated.
2236	This enables the client to implement kinetic scrolling.
2237	See the wl_pointer.axis_source documentation for information on when
2238	this event may be generated.
2239
2240	Any wl_pointer.axis events with the same axis_source after this
2241	event should be considered as the start of a new axis motion.
2242
2243	The timestamp is to be interpreted identical to the timestamp in the
2244	wl_pointer.axis event. The timestamp value may be the same as a
2245	preceding wl_pointer.axis event.
2246      </description>
2247      <arg name="time" type="uint" summary="timestamp with millisecond granularity"/>
2248      <arg name="axis" type="uint" enum="axis" summary="the axis stopped with this event"/>
2249    </event>
2250
2251    <event name="axis_discrete" since="5">
2252      <description summary="axis click event">
2253	Discrete step information for scroll and other axes.
2254
2255	This event carries the axis value of the wl_pointer.axis event in
2256	discrete steps (e.g. mouse wheel clicks).
2257
2258	This event is deprecated with wl_pointer version 8 - this event is not
2259	sent to clients supporting version 8 or later.
2260
2261	This event does not occur on its own, it is coupled with a
2262	wl_pointer.axis event that represents this axis value on a
2263	continuous scale. The protocol guarantees that each axis_discrete
2264	event is always followed by exactly one axis event with the same
2265	axis number within the same wl_pointer.frame. Note that the protocol
2266	allows for other events to occur between the axis_discrete and
2267	its coupled axis event, including other axis_discrete or axis
2268	events. A wl_pointer.frame must not contain more than one axis_discrete
2269	event per axis type.
2270
2271	This event is optional; continuous scrolling devices
2272	like two-finger scrolling on touchpads do not have discrete
2273	steps and do not generate this event.
2274
2275	The discrete value carries the directional information. e.g. a value
2276	of -2 is two steps towards the negative direction of this axis.
2277
2278	The axis number is identical to the axis number in the associated
2279	axis event.
2280
2281	The order of wl_pointer.axis_discrete and wl_pointer.axis_source is
2282	not guaranteed.
2283      </description>
2284      <arg name="axis" type="uint" enum="axis" summary="axis type"/>
2285      <arg name="discrete" type="int" summary="number of steps"/>
2286    </event>
2287
2288    <event name="axis_value120" since="8">
2289      <description summary="axis high-resolution scroll event">
2290	Discrete high-resolution scroll information.
2291
2292	This event carries high-resolution wheel scroll information,
2293	with each multiple of 120 representing one logical scroll step
2294	(a wheel detent). For example, an axis_value120 of 30 is one quarter of
2295	a logical scroll step in the positive direction, a value120 of
2296	-240 are two logical scroll steps in the negative direction within the
2297	same hardware event.
2298	Clients that rely on discrete scrolling should accumulate the
2299	value120 to multiples of 120 before processing the event.
2300
2301	The value120 must not be zero.
2302
2303	This event replaces the wl_pointer.axis_discrete event in clients
2304	supporting wl_pointer version 8 or later.
2305
2306	Where a wl_pointer.axis_source event occurs in the same
2307	wl_pointer.frame, the axis source applies to this event.
2308
2309	The order of wl_pointer.axis_value120 and wl_pointer.axis_source is
2310	not guaranteed.
2311      </description>
2312      <arg name="axis" type="uint" enum="axis" summary="axis type"/>
2313      <arg name="value120" type="int" summary="scroll distance as fraction of 120"/>
2314    </event>
2315
2316    <!-- Version 9 additions -->
2317
2318    <enum name="axis_relative_direction">
2319      <description summary="axis relative direction">
2320	This specifies the direction of the physical motion that caused a
2321	wl_pointer.axis event, relative to the wl_pointer.axis direction.
2322      </description>
2323      <entry name="identical" value="0"
2324	  summary="physical motion matches axis direction"/>
2325      <entry name="inverted" value="1"
2326	  summary="physical motion is the inverse of the axis direction"/>
2327    </enum>
2328
2329    <event name="axis_relative_direction" since="9">
2330      <description summary="axis relative physical direction event">
2331	Relative directional information of the entity causing the axis
2332	motion.
2333
2334	For a wl_pointer.axis event, the wl_pointer.axis_relative_direction
2335	event specifies the movement direction of the entity causing the
2336	wl_pointer.axis event. For example:
2337	- if a user's fingers on a touchpad move down and this
2338	  causes a wl_pointer.axis vertical_scroll down event, the physical
2339	  direction is 'identical'
2340	- if a user's fingers on a touchpad move down and this causes a
2341	  wl_pointer.axis vertical_scroll up scroll up event ('natural
2342	  scrolling'), the physical direction is 'inverted'.
2343
2344	A client may use this information to adjust scroll motion of
2345	components. Specifically, enabling natural scrolling causes the
2346	content to change direction compared to traditional scrolling.
2347	Some widgets like volume control sliders should usually match the
2348	physical direction regardless of whether natural scrolling is
2349	active. This event enables clients to match the scroll direction of
2350	a widget to the physical direction.
2351
2352	This event does not occur on its own, it is coupled with a
2353	wl_pointer.axis event that represents this axis value.
2354	The protocol guarantees that each axis_relative_direction event is
2355	always followed by exactly one axis event with the same
2356	axis number within the same wl_pointer.frame. Note that the protocol
2357	allows for other events to occur between the axis_relative_direction
2358	and its coupled axis event.
2359
2360	The axis number is identical to the axis number in the associated
2361	axis event.
2362
2363	The order of wl_pointer.axis_relative_direction,
2364	wl_pointer.axis_discrete and wl_pointer.axis_source is not
2365	guaranteed.
2366      </description>
2367      <arg name="axis" type="uint" enum="axis" summary="axis type"/>
2368      <arg name="direction" type="uint" enum="axis_relative_direction"
2369	  summary="physical direction relative to axis motion"/>
2370    </event>
2371  </interface>
2372
2373  <interface name="wl_keyboard" version="9">
2374    <description summary="keyboard input device">
2375      The wl_keyboard interface represents one or more keyboards
2376      associated with a seat.
2377    </description>
2378
2379    <enum name="keymap_format">
2380      <description summary="keyboard mapping format">
2381	This specifies the format of the keymap provided to the
2382	client with the wl_keyboard.keymap event.
2383      </description>
2384      <entry name="no_keymap" value="0"
2385	     summary="no keymap; client must understand how to interpret the raw keycode"/>
2386      <entry name="xkb_v1" value="1"
2387	     summary="libxkbcommon compatible, null-terminated string; to determine the xkb keycode, clients must add 8 to the key event keycode"/>
2388    </enum>
2389
2390    <event name="keymap">
2391      <description summary="keyboard mapping">
2392	This event provides a file descriptor to the client which can be
2393	memory-mapped in read-only mode to provide a keyboard mapping
2394	description.
2395
2396	From version 7 onwards, the fd must be mapped with MAP_PRIVATE by
2397	the recipient, as MAP_SHARED may fail.
2398      </description>
2399      <arg name="format" type="uint" enum="keymap_format" summary="keymap format"/>
2400      <arg name="fd" type="fd" summary="keymap file descriptor"/>
2401      <arg name="size" type="uint" summary="keymap size, in bytes"/>
2402    </event>
2403
2404    <event name="enter">
2405      <description summary="enter event">
2406	Notification that this seat's keyboard focus is on a certain
2407	surface.
2408
2409	The compositor must send the wl_keyboard.modifiers event after this
2410	event.
2411      </description>
2412      <arg name="serial" type="uint" summary="serial number of the enter event"/>
2413      <arg name="surface" type="object" interface="wl_surface" summary="surface gaining keyboard focus"/>
2414      <arg name="keys" type="array" summary="the currently pressed keys"/>
2415    </event>
2416
2417    <event name="leave">
2418      <description summary="leave event">
2419	Notification that this seat's keyboard focus is no longer on
2420	a certain surface.
2421
2422	The leave notification is sent before the enter notification
2423	for the new focus.
2424
2425	After this event client must assume that all keys, including modifiers,
2426	are lifted and also it must stop key repeating if there's some going on.
2427      </description>
2428      <arg name="serial" type="uint" summary="serial number of the leave event"/>
2429      <arg name="surface" type="object" interface="wl_surface" summary="surface that lost keyboard focus"/>
2430    </event>
2431
2432    <enum name="key_state">
2433      <description summary="physical key state">
2434	Describes the physical state of a key that produced the key event.
2435      </description>
2436      <entry name="released" value="0" summary="key is not pressed"/>
2437      <entry name="pressed" value="1" summary="key is pressed"/>
2438    </enum>
2439
2440    <event name="key">
2441      <description summary="key event">
2442	A key was pressed or released.
2443	The time argument is a timestamp with millisecond
2444	granularity, with an undefined base.
2445
2446	The key is a platform-specific key code that can be interpreted
2447	by feeding it to the keyboard mapping (see the keymap event).
2448
2449	If this event produces a change in modifiers, then the resulting
2450	wl_keyboard.modifiers event must be sent after this event.
2451      </description>
2452      <arg name="serial" type="uint" summary="serial number of the key event"/>
2453      <arg name="time" type="uint" summary="timestamp with millisecond granularity"/>
2454      <arg name="key" type="uint" summary="key that produced the event"/>
2455      <arg name="state" type="uint" enum="key_state" summary="physical state of the key"/>
2456    </event>
2457
2458    <event name="modifiers">
2459      <description summary="modifier and group state">
2460	Notifies clients that the modifier and/or group state has
2461	changed, and it should update its local state.
2462      </description>
2463      <arg name="serial" type="uint" summary="serial number of the modifiers event"/>
2464      <arg name="mods_depressed" type="uint" summary="depressed modifiers"/>
2465      <arg name="mods_latched" type="uint" summary="latched modifiers"/>
2466      <arg name="mods_locked" type="uint" summary="locked modifiers"/>
2467      <arg name="group" type="uint" summary="keyboard layout"/>
2468    </event>
2469
2470    <!-- Version 3 additions -->
2471
2472    <request name="release" type="destructor" since="3">
2473      <description summary="release the keyboard object"/>
2474    </request>
2475
2476    <!-- Version 4 additions -->
2477
2478    <event name="repeat_info" since="4">
2479      <description summary="repeat rate and delay">
2480	Informs the client about the keyboard's repeat rate and delay.
2481
2482	This event is sent as soon as the wl_keyboard object has been created,
2483	and is guaranteed to be received by the client before any key press
2484	event.
2485
2486	Negative values for either rate or delay are illegal. A rate of zero
2487	will disable any repeating (regardless of the value of delay).
2488
2489	This event can be sent later on as well with a new value if necessary,
2490	so clients should continue listening for the event past the creation
2491	of wl_keyboard.
2492      </description>
2493      <arg name="rate" type="int"
2494	   summary="the rate of repeating keys in characters per second"/>
2495      <arg name="delay" type="int"
2496	   summary="delay in milliseconds since key down until repeating starts"/>
2497    </event>
2498  </interface>
2499
2500  <interface name="wl_touch" version="9">
2501    <description summary="touchscreen input device">
2502      The wl_touch interface represents a touchscreen
2503      associated with a seat.
2504
2505      Touch interactions can consist of one or more contacts.
2506      For each contact, a series of events is generated, starting
2507      with a down event, followed by zero or more motion events,
2508      and ending with an up event. Events relating to the same
2509      contact point can be identified by the ID of the sequence.
2510    </description>
2511
2512    <event name="down">
2513      <description summary="touch down event and beginning of a touch sequence">
2514	A new touch point has appeared on the surface. This touch point is
2515	assigned a unique ID. Future events from this touch point reference
2516	this ID. The ID ceases to be valid after a touch up event and may be
2517	reused in the future.
2518      </description>
2519      <arg name="serial" type="uint" summary="serial number of the touch down event"/>
2520      <arg name="time" type="uint" summary="timestamp with millisecond granularity"/>
2521      <arg name="surface" type="object" interface="wl_surface" summary="surface touched"/>
2522      <arg name="id" type="int" summary="the unique ID of this touch point"/>
2523      <arg name="x" type="fixed" summary="surface-local x coordinate"/>
2524      <arg name="y" type="fixed" summary="surface-local y coordinate"/>
2525    </event>
2526
2527    <event name="up">
2528      <description summary="end of a touch event sequence">
2529	The touch point has disappeared. No further events will be sent for
2530	this touch point and the touch point's ID is released and may be
2531	reused in a future touch down event.
2532      </description>
2533      <arg name="serial" type="uint" summary="serial number of the touch up event"/>
2534      <arg name="time" type="uint" summary="timestamp with millisecond granularity"/>
2535      <arg name="id" type="int" summary="the unique ID of this touch point"/>
2536    </event>
2537
2538    <event name="motion">
2539      <description summary="update of touch point coordinates">
2540	A touch point has changed coordinates.
2541      </description>
2542      <arg name="time" type="uint" summary="timestamp with millisecond granularity"/>
2543      <arg name="id" type="int" summary="the unique ID of this touch point"/>
2544      <arg name="x" type="fixed" summary="surface-local x coordinate"/>
2545      <arg name="y" type="fixed" summary="surface-local y coordinate"/>
2546    </event>
2547
2548    <event name="frame">
2549      <description summary="end of touch frame event">
2550	Indicates the end of a set of events that logically belong together.
2551	A client is expected to accumulate the data in all events within the
2552	frame before proceeding.
2553
2554	A wl_touch.frame terminates at least one event but otherwise no
2555	guarantee is provided about the set of events within a frame. A client
2556	must assume that any state not updated in a frame is unchanged from the
2557	previously known state.
2558      </description>
2559    </event>
2560
2561    <event name="cancel">
2562      <description summary="touch session cancelled">
2563	Sent if the compositor decides the touch stream is a global
2564	gesture. No further events are sent to the clients from that
2565	particular gesture. Touch cancellation applies to all touch points
2566	currently active on this client's surface. The client is
2567	responsible for finalizing the touch points, future touch points on
2568	this surface may reuse the touch point ID.
2569      </description>
2570    </event>
2571
2572    <!-- Version 3 additions -->
2573
2574    <request name="release" type="destructor" since="3">
2575      <description summary="release the touch object"/>
2576    </request>
2577
2578    <!-- Version 6 additions -->
2579
2580    <event name="shape" since="6">
2581      <description summary="update shape of touch point">
2582	Sent when a touchpoint has changed its shape.
2583
2584	This event does not occur on its own. It is sent before a
2585	wl_touch.frame event and carries the new shape information for
2586	any previously reported, or new touch points of that frame.
2587
2588	Other events describing the touch point such as wl_touch.down,
2589	wl_touch.motion or wl_touch.orientation may be sent within the
2590	same wl_touch.frame. A client should treat these events as a single
2591	logical touch point update. The order of wl_touch.shape,
2592	wl_touch.orientation and wl_touch.motion is not guaranteed.
2593	A wl_touch.down event is guaranteed to occur before the first
2594	wl_touch.shape event for this touch ID but both events may occur within
2595	the same wl_touch.frame.
2596
2597	A touchpoint shape is approximated by an ellipse through the major and
2598	minor axis length. The major axis length describes the longer diameter
2599	of the ellipse, while the minor axis length describes the shorter
2600	diameter. Major and minor are orthogonal and both are specified in
2601	surface-local coordinates. The center of the ellipse is always at the
2602	touchpoint location as reported by wl_touch.down or wl_touch.move.
2603
2604	This event is only sent by the compositor if the touch device supports
2605	shape reports. The client has to make reasonable assumptions about the
2606	shape if it did not receive this event.
2607      </description>
2608      <arg name="id" type="int" summary="the unique ID of this touch point"/>
2609      <arg name="major" type="fixed" summary="length of the major axis in surface-local coordinates"/>
2610      <arg name="minor" type="fixed" summary="length of the minor axis in surface-local coordinates"/>
2611    </event>
2612
2613    <event name="orientation" since="6">
2614      <description summary="update orientation of touch point">
2615	Sent when a touchpoint has changed its orientation.
2616
2617	This event does not occur on its own. It is sent before a
2618	wl_touch.frame event and carries the new shape information for
2619	any previously reported, or new touch points of that frame.
2620
2621	Other events describing the touch point such as wl_touch.down,
2622	wl_touch.motion or wl_touch.shape may be sent within the
2623	same wl_touch.frame. A client should treat these events as a single
2624	logical touch point update. The order of wl_touch.shape,
2625	wl_touch.orientation and wl_touch.motion is not guaranteed.
2626	A wl_touch.down event is guaranteed to occur before the first
2627	wl_touch.orientation event for this touch ID but both events may occur
2628	within the same wl_touch.frame.
2629
2630	The orientation describes the clockwise angle of a touchpoint's major
2631	axis to the positive surface y-axis and is normalized to the -180 to
2632	+180 degree range. The granularity of orientation depends on the touch
2633	device, some devices only support binary rotation values between 0 and
2634	90 degrees.
2635
2636	This event is only sent by the compositor if the touch device supports
2637	orientation reports.
2638      </description>
2639      <arg name="id" type="int" summary="the unique ID of this touch point"/>
2640      <arg name="orientation" type="fixed" summary="angle between major axis and positive surface y-axis in degrees"/>
2641    </event>
2642  </interface>
2643
2644  <interface name="wl_output" version="4">
2645    <description summary="compositor output region">
2646      An output describes part of the compositor geometry.  The
2647      compositor works in the 'compositor coordinate system' and an
2648      output corresponds to a rectangular area in that space that is
2649      actually visible.  This typically corresponds to a monitor that
2650      displays part of the compositor space.  This object is published
2651      as global during start up, or when a monitor is hotplugged.
2652    </description>
2653
2654    <enum name="subpixel">
2655      <description summary="subpixel geometry information">
2656	This enumeration describes how the physical
2657	pixels on an output are laid out.
2658      </description>
2659      <entry name="unknown" value="0" summary="unknown geometry"/>
2660      <entry name="none" value="1" summary="no geometry"/>
2661      <entry name="horizontal_rgb" value="2" summary="horizontal RGB"/>
2662      <entry name="horizontal_bgr" value="3" summary="horizontal BGR"/>
2663      <entry name="vertical_rgb" value="4" summary="vertical RGB"/>
2664      <entry name="vertical_bgr" value="5" summary="vertical BGR"/>
2665    </enum>
2666
2667    <enum name="transform">
2668      <description summary="transform from framebuffer to output">
2669	This describes the transform that a compositor will apply to a
2670	surface to compensate for the rotation or mirroring of an
2671	output device.
2672
2673	The flipped values correspond to an initial flip around a
2674	vertical axis followed by rotation.
2675
2676	The purpose is mainly to allow clients to render accordingly and
2677	tell the compositor, so that for fullscreen surfaces, the
2678	compositor will still be able to scan out directly from client
2679	surfaces.
2680      </description>
2681      <entry name="normal" value="0" summary="no transform"/>
2682      <entry name="90" value="1" summary="90 degrees counter-clockwise"/>
2683      <entry name="180" value="2" summary="180 degrees counter-clockwise"/>
2684      <entry name="270" value="3" summary="270 degrees counter-clockwise"/>
2685      <entry name="flipped" value="4" summary="180 degree flip around a vertical axis"/>
2686      <entry name="flipped_90" value="5" summary="flip and rotate 90 degrees counter-clockwise"/>
2687      <entry name="flipped_180" value="6" summary="flip and rotate 180 degrees counter-clockwise"/>
2688      <entry name="flipped_270" value="7" summary="flip and rotate 270 degrees counter-clockwise"/>
2689    </enum>
2690
2691    <event name="geometry">
2692      <description summary="properties of the output">
2693	The geometry event describes geometric properties of the output.
2694	The event is sent when binding to the output object and whenever
2695	any of the properties change.
2696
2697	The physical size can be set to zero if it doesn't make sense for this
2698	output (e.g. for projectors or virtual outputs).
2699
2700	The geometry event will be followed by a done event (starting from
2701	version 2).
2702
2703	Note: wl_output only advertises partial information about the output
2704	position and identification. Some compositors, for instance those not
2705	implementing a desktop-style output layout or those exposing virtual
2706	outputs, might fake this information. Instead of using x and y, clients
2707	should use xdg_output.logical_position. Instead of using make and model,
2708	clients should use name and description.
2709      </description>
2710      <arg name="x" type="int"
2711	   summary="x position within the global compositor space"/>
2712      <arg name="y" type="int"
2713	   summary="y position within the global compositor space"/>
2714      <arg name="physical_width" type="int"
2715	   summary="width in millimeters of the output"/>
2716      <arg name="physical_height" type="int"
2717	   summary="height in millimeters of the output"/>
2718      <arg name="subpixel" type="int" enum="subpixel"
2719	   summary="subpixel orientation of the output"/>
2720      <arg name="make" type="string"
2721	   summary="textual description of the manufacturer"/>
2722      <arg name="model" type="string"
2723	   summary="textual description of the model"/>
2724      <arg name="transform" type="int" enum="transform"
2725	   summary="transform that maps framebuffer to output"/>
2726    </event>
2727
2728    <enum name="mode" bitfield="true">
2729      <description summary="mode information">
2730	These flags describe properties of an output mode.
2731	They are used in the flags bitfield of the mode event.
2732      </description>
2733      <entry name="current" value="0x1"
2734	     summary="indicates this is the current mode"/>
2735      <entry name="preferred" value="0x2"
2736	     summary="indicates this is the preferred mode"/>
2737    </enum>
2738
2739    <event name="mode">
2740      <description summary="advertise available modes for the output">
2741	The mode event describes an available mode for the output.
2742
2743	The event is sent when binding to the output object and there
2744	will always be one mode, the current mode.  The event is sent
2745	again if an output changes mode, for the mode that is now
2746	current.  In other words, the current mode is always the last
2747	mode that was received with the current flag set.
2748
2749	Non-current modes are deprecated. A compositor can decide to only
2750	advertise the current mode and never send other modes. Clients
2751	should not rely on non-current modes.
2752
2753	The size of a mode is given in physical hardware units of
2754	the output device. This is not necessarily the same as
2755	the output size in the global compositor space. For instance,
2756	the output may be scaled, as described in wl_output.scale,
2757	or transformed, as described in wl_output.transform. Clients
2758	willing to retrieve the output size in the global compositor
2759	space should use xdg_output.logical_size instead.
2760
2761	The vertical refresh rate can be set to zero if it doesn't make
2762	sense for this output (e.g. for virtual outputs).
2763
2764	The mode event will be followed by a done event (starting from
2765	version 2).
2766
2767	Clients should not use the refresh rate to schedule frames. Instead,
2768	they should use the wl_surface.frame event or the presentation-time
2769	protocol.
2770
2771	Note: this information is not always meaningful for all outputs. Some
2772	compositors, such as those exposing virtual outputs, might fake the
2773	refresh rate or the size.
2774      </description>
2775      <arg name="flags" type="uint" enum="mode" summary="bitfield of mode flags"/>
2776      <arg name="width" type="int" summary="width of the mode in hardware units"/>
2777      <arg name="height" type="int" summary="height of the mode in hardware units"/>
2778      <arg name="refresh" type="int" summary="vertical refresh rate in mHz"/>
2779    </event>
2780
2781    <!-- Version 2 additions -->
2782
2783    <event name="done" since="2">
2784      <description summary="sent all information about output">
2785	This event is sent after all other properties have been
2786	sent after binding to the output object and after any
2787	other property changes done after that. This allows
2788	changes to the output properties to be seen as
2789	atomic, even if they happen via multiple events.
2790      </description>
2791    </event>
2792
2793    <event name="scale" since="2">
2794      <description summary="output scaling properties">
2795	This event contains scaling geometry information
2796	that is not in the geometry event. It may be sent after
2797	binding the output object or if the output scale changes
2798	later. If it is not sent, the client should assume a
2799	scale of 1.
2800
2801	A scale larger than 1 means that the compositor will
2802	automatically scale surface buffers by this amount
2803	when rendering. This is used for very high resolution
2804	displays where applications rendering at the native
2805	resolution would be too small to be legible.
2806
2807	It is intended that scaling aware clients track the
2808	current output of a surface, and if it is on a scaled
2809	output it should use wl_surface.set_buffer_scale with
2810	the scale of the output. That way the compositor can
2811	avoid scaling the surface, and the client can supply
2812	a higher detail image.
2813
2814	The scale event will be followed by a done event.
2815      </description>
2816      <arg name="factor" type="int" summary="scaling factor of output"/>
2817    </event>
2818
2819    <!-- Version 3 additions -->
2820
2821    <request name="release" type="destructor" since="3">
2822      <description summary="release the output object">
2823	Using this request a client can tell the server that it is not going to
2824	use the output object anymore.
2825      </description>
2826    </request>
2827
2828    <!-- Version 4 additions -->
2829
2830    <event name="name" since="4">
2831      <description summary="name of this output">
2832	Many compositors will assign user-friendly names to their outputs, show
2833	them to the user, allow the user to refer to an output, etc. The client
2834	may wish to know this name as well to offer the user similar behaviors.
2835
2836	The name is a UTF-8 string with no convention defined for its contents.
2837	Each name is unique among all wl_output globals. The name is only
2838	guaranteed to be unique for the compositor instance.
2839
2840	The same output name is used for all clients for a given wl_output
2841	global. Thus, the name can be shared across processes to refer to a
2842	specific wl_output global.
2843
2844	The name is not guaranteed to be persistent across sessions, thus cannot
2845	be used to reliably identify an output in e.g. configuration files.
2846
2847	Examples of names include 'HDMI-A-1', 'WL-1', 'X11-1', etc. However, do
2848	not assume that the name is a reflection of an underlying DRM connector,
2849	X11 connection, etc.
2850
2851	The name event is sent after binding the output object. This event is
2852	only sent once per output object, and the name does not change over the
2853	lifetime of the wl_output global.
2854
2855	Compositors may re-use the same output name if the wl_output global is
2856	destroyed and re-created later. Compositors should avoid re-using the
2857	same name if possible.
2858
2859	The name event will be followed by a done event.
2860      </description>
2861      <arg name="name" type="string" summary="output name"/>
2862    </event>
2863
2864    <event name="description" since="4">
2865      <description summary="human-readable description of this output">
2866	Many compositors can produce human-readable descriptions of their
2867	outputs. The client may wish to know this description as well, e.g. for
2868	output selection purposes.
2869
2870	The description is a UTF-8 string with no convention defined for its
2871	contents. The description is not guaranteed to be unique among all
2872	wl_output globals. Examples might include 'Foocorp 11" Display' or
2873	'Virtual X11 output via :1'.
2874
2875	The description event is sent after binding the output object and
2876	whenever the description changes. The description is optional, and may
2877	not be sent at all.
2878
2879	The description event will be followed by a done event.
2880      </description>
2881      <arg name="description" type="string" summary="output description"/>
2882    </event>
2883  </interface>
2884
2885  <interface name="wl_region" version="1">
2886    <description summary="region interface">
2887      A region object describes an area.
2888
2889      Region objects are used to describe the opaque and input
2890      regions of a surface.
2891    </description>
2892
2893    <request name="destroy" type="destructor">
2894      <description summary="destroy region">
2895	Destroy the region.  This will invalidate the object ID.
2896      </description>
2897    </request>
2898
2899    <request name="add">
2900      <description summary="add rectangle to region">
2901	Add the specified rectangle to the region.
2902      </description>
2903      <arg name="x" type="int" summary="region-local x coordinate"/>
2904      <arg name="y" type="int" summary="region-local y coordinate"/>
2905      <arg name="width" type="int" summary="rectangle width"/>
2906      <arg name="height" type="int" summary="rectangle height"/>
2907    </request>
2908
2909    <request name="subtract">
2910      <description summary="subtract rectangle from region">
2911	Subtract the specified rectangle from the region.
2912      </description>
2913      <arg name="x" type="int" summary="region-local x coordinate"/>
2914      <arg name="y" type="int" summary="region-local y coordinate"/>
2915      <arg name="width" type="int" summary="rectangle width"/>
2916      <arg name="height" type="int" summary="rectangle height"/>
2917    </request>
2918  </interface>
2919
2920  <interface name="wl_subcompositor" version="1">
2921    <description summary="sub-surface compositing">
2922      The global interface exposing sub-surface compositing capabilities.
2923      A wl_surface, that has sub-surfaces associated, is called the
2924      parent surface. Sub-surfaces can be arbitrarily nested and create
2925      a tree of sub-surfaces.
2926
2927      The root surface in a tree of sub-surfaces is the main
2928      surface. The main surface cannot be a sub-surface, because
2929      sub-surfaces must always have a parent.
2930
2931      A main surface with its sub-surfaces forms a (compound) window.
2932      For window management purposes, this set of wl_surface objects is
2933      to be considered as a single window, and it should also behave as
2934      such.
2935
2936      The aim of sub-surfaces is to offload some of the compositing work
2937      within a window from clients to the compositor. A prime example is
2938      a video player with decorations and video in separate wl_surface
2939      objects. This should allow the compositor to pass YUV video buffer
2940      processing to dedicated overlay hardware when possible.
2941    </description>
2942
2943    <request name="destroy" type="destructor">
2944      <description summary="unbind from the subcompositor interface">
2945	Informs the server that the client will not be using this
2946	protocol object anymore. This does not affect any other
2947	objects, wl_subsurface objects included.
2948      </description>
2949    </request>
2950
2951    <enum name="error">
2952      <entry name="bad_surface" value="0"
2953	     summary="the to-be sub-surface is invalid"/>
2954      <entry name="bad_parent" value="1"
2955	     summary="the to-be sub-surface parent is invalid"/>
2956    </enum>
2957
2958    <request name="get_subsurface">
2959      <description summary="give a surface the role sub-surface">
2960	Create a sub-surface interface for the given surface, and
2961	associate it with the given parent surface. This turns a
2962	plain wl_surface into a sub-surface.
2963
2964	The to-be sub-surface must not already have another role, and it
2965	must not have an existing wl_subsurface object. Otherwise the
2966	bad_surface protocol error is raised.
2967
2968	Adding sub-surfaces to a parent is a double-buffered operation on the
2969	parent (see wl_surface.commit). The effect of adding a sub-surface
2970	becomes visible on the next time the state of the parent surface is
2971	applied.
2972
2973	The parent surface must not be one of the child surface's descendants,
2974	and the parent must be different from the child surface, otherwise the
2975	bad_parent protocol error is raised.
2976
2977	This request modifies the behaviour of wl_surface.commit request on
2978	the sub-surface, see the documentation on wl_subsurface interface.
2979      </description>
2980      <arg name="id" type="new_id" interface="wl_subsurface"
2981	   summary="the new sub-surface object ID"/>
2982      <arg name="surface" type="object" interface="wl_surface"
2983	   summary="the surface to be turned into a sub-surface"/>
2984      <arg name="parent" type="object" interface="wl_surface"
2985	   summary="the parent surface"/>
2986    </request>
2987  </interface>
2988
2989  <interface name="wl_subsurface" version="1">
2990    <description summary="sub-surface interface to a wl_surface">
2991      An additional interface to a wl_surface object, which has been
2992      made a sub-surface. A sub-surface has one parent surface. A
2993      sub-surface's size and position are not limited to that of the parent.
2994      Particularly, a sub-surface is not automatically clipped to its
2995      parent's area.
2996
2997      A sub-surface becomes mapped, when a non-NULL wl_buffer is applied
2998      and the parent surface is mapped. The order of which one happens
2999      first is irrelevant. A sub-surface is hidden if the parent becomes
3000      hidden, or if a NULL wl_buffer is applied. These rules apply
3001      recursively through the tree of surfaces.
3002
3003      The behaviour of a wl_surface.commit request on a sub-surface
3004      depends on the sub-surface's mode. The possible modes are
3005      synchronized and desynchronized, see methods
3006      wl_subsurface.set_sync and wl_subsurface.set_desync. Synchronized
3007      mode caches the wl_surface state to be applied when the parent's
3008      state gets applied, and desynchronized mode applies the pending
3009      wl_surface state directly. A sub-surface is initially in the
3010      synchronized mode.
3011
3012      Sub-surfaces also have another kind of state, which is managed by
3013      wl_subsurface requests, as opposed to wl_surface requests. This
3014      state includes the sub-surface position relative to the parent
3015      surface (wl_subsurface.set_position), and the stacking order of
3016      the parent and its sub-surfaces (wl_subsurface.place_above and
3017      .place_below). This state is applied when the parent surface's
3018      wl_surface state is applied, regardless of the sub-surface's mode.
3019      As the exception, set_sync and set_desync are effective immediately.
3020
3021      The main surface can be thought to be always in desynchronized mode,
3022      since it does not have a parent in the sub-surfaces sense.
3023
3024      Even if a sub-surface is in desynchronized mode, it will behave as
3025      in synchronized mode, if its parent surface behaves as in
3026      synchronized mode. This rule is applied recursively throughout the
3027      tree of surfaces. This means, that one can set a sub-surface into
3028      synchronized mode, and then assume that all its child and grand-child
3029      sub-surfaces are synchronized, too, without explicitly setting them.
3030
3031      Destroying a sub-surface takes effect immediately. If you need to
3032      synchronize the removal of a sub-surface to the parent surface update,
3033      unmap the sub-surface first by attaching a NULL wl_buffer, update parent,
3034      and then destroy the sub-surface.
3035
3036      If the parent wl_surface object is destroyed, the sub-surface is
3037      unmapped.
3038    </description>
3039
3040    <request name="destroy" type="destructor">
3041      <description summary="remove sub-surface interface">
3042	The sub-surface interface is removed from the wl_surface object
3043	that was turned into a sub-surface with a
3044	wl_subcompositor.get_subsurface request. The wl_surface's association
3045	to the parent is deleted. The wl_surface is unmapped immediately.
3046      </description>
3047    </request>
3048
3049    <enum name="error">
3050      <entry name="bad_surface" value="0"
3051	     summary="wl_surface is not a sibling or the parent"/>
3052    </enum>
3053
3054    <request name="set_position">
3055      <description summary="reposition the sub-surface">
3056	This schedules a sub-surface position change.
3057	The sub-surface will be moved so that its origin (top left
3058	corner pixel) will be at the location x, y of the parent surface
3059	coordinate system. The coordinates are not restricted to the parent
3060	surface area. Negative values are allowed.
3061
3062	The scheduled coordinates will take effect whenever the state of the
3063	parent surface is applied. When this happens depends on whether the
3064	parent surface is in synchronized mode or not. See
3065	wl_subsurface.set_sync and wl_subsurface.set_desync for details.
3066
3067	If more than one set_position request is invoked by the client before
3068	the commit of the parent surface, the position of a new request always
3069	replaces the scheduled position from any previous request.
3070
3071	The initial position is 0, 0.
3072      </description>
3073      <arg name="x" type="int" summary="x coordinate in the parent surface"/>
3074      <arg name="y" type="int" summary="y coordinate in the parent surface"/>
3075    </request>
3076
3077    <request name="place_above">
3078      <description summary="restack the sub-surface">
3079	This sub-surface is taken from the stack, and put back just
3080	above the reference surface, changing the z-order of the sub-surfaces.
3081	The reference surface must be one of the sibling surfaces, or the
3082	parent surface. Using any other surface, including this sub-surface,
3083	will cause a protocol error.
3084
3085	The z-order is double-buffered. Requests are handled in order and
3086	applied immediately to a pending state. The final pending state is
3087	copied to the active state the next time the state of the parent
3088	surface is applied. When this happens depends on whether the parent
3089	surface is in synchronized mode or not. See wl_subsurface.set_sync and
3090	wl_subsurface.set_desync for details.
3091
3092	A new sub-surface is initially added as the top-most in the stack
3093	of its siblings and parent.
3094      </description>
3095      <arg name="sibling" type="object" interface="wl_surface"
3096	   summary="the reference surface"/>
3097    </request>
3098
3099    <request name="place_below">
3100      <description summary="restack the sub-surface">
3101	The sub-surface is placed just below the reference surface.
3102	See wl_subsurface.place_above.
3103      </description>
3104      <arg name="sibling" type="object" interface="wl_surface"
3105	   summary="the reference surface"/>
3106    </request>
3107
3108    <request name="set_sync">
3109      <description summary="set sub-surface to synchronized mode">
3110	Change the commit behaviour of the sub-surface to synchronized
3111	mode, also described as the parent dependent mode.
3112
3113	In synchronized mode, wl_surface.commit on a sub-surface will
3114	accumulate the committed state in a cache, but the state will
3115	not be applied and hence will not change the compositor output.
3116	The cached state is applied to the sub-surface immediately after
3117	the parent surface's state is applied. This ensures atomic
3118	updates of the parent and all its synchronized sub-surfaces.
3119	Applying the cached state will invalidate the cache, so further
3120	parent surface commits do not (re-)apply old state.
3121
3122	See wl_subsurface for the recursive effect of this mode.
3123      </description>
3124    </request>
3125
3126    <request name="set_desync">
3127      <description summary="set sub-surface to desynchronized mode">
3128	Change the commit behaviour of the sub-surface to desynchronized
3129	mode, also described as independent or freely running mode.
3130
3131	In desynchronized mode, wl_surface.commit on a sub-surface will
3132	apply the pending state directly, without caching, as happens
3133	normally with a wl_surface. Calling wl_surface.commit on the
3134	parent surface has no effect on the sub-surface's wl_surface
3135	state. This mode allows a sub-surface to be updated on its own.
3136
3137	If cached state exists when wl_surface.commit is called in
3138	desynchronized mode, the pending state is added to the cached
3139	state, and applied as a whole. This invalidates the cache.
3140
3141	Note: even if a sub-surface is set to desynchronized, a parent
3142	sub-surface may override it to behave as synchronized. For details,
3143	see wl_subsurface.
3144
3145	If a surface's parent surface behaves as desynchronized, then
3146	the cached state is applied on set_desync.
3147      </description>
3148    </request>
3149  </interface>
3150
3151</protocol>
3152