1<?xml version="1.0" encoding="UTF-8"?>
2<protocol name="xdg_session_management_v1">
3 <copyright>
4 Copyright 2018 Mike Blumenkrantz
5 Copyright 2018 Samsung Electronics Co., Ltd
6 Copyright 2018 Red Hat Inc.
7
8 Permission is hereby granted, free of charge, to any person obtaining a
9 copy of this software and associated documentation files (the "Software"),
10 to deal in the Software without restriction, including without limitation
11 the rights to use, copy, modify, merge, publish, distribute, sublicense,
12 and/or sell copies of the Software, and to permit persons to whom the
13 Software is furnished to do so, subject to the following conditions:
14
15 The above copyright notice and this permission notice (including the next
16 paragraph) shall be included in all copies or substantial portions of the
17 Software.
18
19 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
20 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
21 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
22 THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
23 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
24 FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
25 DEALINGS IN THE SOFTWARE.
26 </copyright>
27
28 <description summary="Protocol for managing application sessions">
29 This description provides a high-level overview of the interplay between
30 the interfaces defined this protocol. For details, see the protocol
31 specification.
32
33 The xdg_session_manager protocol declares interfaces necessary to
34 allow clients to restore toplevel state from previous executions. The
35 xdg_session_manager_v1.get_session request can be used to obtain a
36 xdg_session_v1 resource representing the state of a set of toplevels.
37
38 Clients may obtain the session string to use in future calls through
39 the xdg_session_v1.created event. Compositors will use this string
40 as an identifiable token for future runs, possibly storing data about
41 the related toplevels in persistent storage. Clients that wish to
42 track sessions in multiple environments may use the $XDG_CURRENT_DESKTOP
43 environment variable.
44
45 Toplevels are managed through the xdg_session_v1.add_toplevel and
46 xdg_session_v1.remove_toplevel pair of requests. Clients will explicitly
47 request a toplevel to be restored according to prior state through the
48 xdg_session_v1.restore_toplevel request before the toplevel is mapped.
49
50 Compositors may store session information up to any arbitrary level, and
51 apply any limits and policies to the amount of data stored and its lifetime.
52 Clients must account for missing sessions and partial session restoration.
53
54 Warning! The protocol described in this file is currently in the testing
55 phase. Backward compatible changes may be added together with the
56 corresponding interface version bump. Backward incompatible changes can
57 only be done by creating a new major version of the extension.
58 </description>
59
60 <interface name="xdg_session_manager_v1" version="1">
61 <description summary="manage sessions for applications">
62 The xdg_session_manager_v1 interface defines base requests for creating and
63 managing a session for an application. Sessions persist across application
64 and compositor restarts unless explicitly destroyed. A session is created
65 for the purpose of maintaining an application's xdg_toplevel surfaces
66 across compositor or application restarts. The compositor should remember
67 as many states as possible for surfaces in a given session, but there is
68 no requirement for which states must be remembered.
69
70 Policies such as cache eviction are declared an implementation detail of
71 the compositor. Clients should account for no longer existing sessions.
72 </description>
73
74 <enum name="error">
75 <entry name="in_use" summary="a requested session is already in use"
76 value="1"/>
77 <entry name="invalid_session_id" summary="invalid session identifier"
78 value="2"/>
79 <entry name="invalid_reason" summary="invalid reason" value="3"/>
80 </enum>
81
82 <enum name="reason">
83 <description summary="reason for getting a session">
84 The reason may determine in what way a session restores the window
85 management state of associated toplevels.
86
87 For example newly launched applications might be launched on the active
88 workspace with restored size and position, while a recovered
89 application might restore additional state such as active workspace and
90 stacking order.
91 </description>
92 <entry name="launch" value="1">
93 <description summary="an app is newly launched">
94 A new app instance is launched, for example from an app launcher.
95 </description>
96 </entry>
97 <entry name="recover" value="2">
98 <description summary="an app recovered">
99 An app instance is recovering from for example a compositor or app crash.
100 </description>
101 </entry>
102 <entry name="session_restore" value="3">
103 <description summary="an app restored">
104 An app instance is restored, for example part of a restored session, or
105 restored from having been temporarily terminated due to resource
106 constraints.
107 </description>
108 </entry>
109 </enum>
110
111 <request name="destroy" type="destructor">
112 <description summary="Destroy this object">
113 Destroy the manager object. The existing session objects will be
114 unaffected.
115 </description>
116 </request>
117
118 <request name="get_session">
119 <description summary="create or restore a session">
120 Create a session object corresponding to either an existing session
121 identified by the given session identifier string or a new session.
122 While the session object exists, the session is considered to be "in
123 use".
124
125 If an identifier string represents a session that is currently actively
126 in use by the the same client, an 'in_use' error is raised. If some
127 other client is currently using the same session, the new session will
128 replace managing the associated state.
129
130 If the reason is not a valid enum entry, the 'invalid_reason' protocol
131 error is raised.
132
133 NULL is passed to initiate a new session. If a session_id is passed
134 which does not represent a valid session, the compositor treats it as if
135 NULL had been passed.
136
137 The session id string must be UTF-8 encoded. It is also limited by the
138 maximum length of wayland messages (around 4KB). The 'invalid_session_id'
139 protocol error will be raised if an invalid string is provided.
140
141 A client is allowed to have any number of in use sessions at the same
142 time.
143 </description>
144 <arg name="id" type="new_id" interface="xdg_session_v1"/>
145 <arg name="reason" type="uint" enum="reason"
146 summary="reason for session"/>
147 <arg name="session_id" type="string"
148 summary="the session to restore"
149 allow-null="true"/>
150 </request>
151 </interface>
152
153 <interface name="xdg_session_v1" version="1">
154 <description summary="A session for an application">
155 A xdg_session_v1 object represents a session for an application. While the
156 object exists, all surfaces which have been added to the session will
157 have states stored by the compositor which can be reapplied at a later
158 time. Two sessions cannot exist for the same identifier string.
159
160 States for surfaces added to a session are automatically updated by the
161 compositor when they are changed.
162 </description>
163
164 <enum name="error">
165 <entry name="name_in_use"
166 summary="toplevel name is already in use"
167 value="1"/>
168 <entry name="already_mapped"
169 summary="toplevel was already mapped when restored"
170 value="2"/>
171 <entry name="invalid_name"
172 summary="provided toplevel name is invalid"
173 value="3"/>
174 <entry name="already_added"
175 summary="toplevel already added"
176 value="4"/>
177 </enum>
178
179 <request name="destroy" type="destructor">
180 <description summary="Destroy the session">
181 Destroy a session object, preserving the current state but not continuing
182 to make further updates if state changes occur. This makes the associated
183 xdg_toplevel_session_v1 objects inert.
184 </description>
185 </request>
186
187 <request name="remove" type="destructor">
188 <description summary="Remove the session">
189 Remove the session, making it no longer available for restoration. A
190 compositor should in response to this request remove the data related to
191 this session from its storage.
192 </description>
193 </request>
194
195 <request name="add_toplevel">
196 <description summary="add a new surface to the session">
197 Attempt to add a given surface to the session. The passed name is used
198 to identify what window is being restored, and may be used to store
199 window specific state within the session.
200
201 The name given to the toplevel must not correspond to any previously
202 existing toplevel names in the session. If the name matches an already
203 known toplevel name in the session, a 'name_in_use' protocol error will
204 be raised.
205
206 The toplevel object must not be added more than once to any session
207 created by the client, otherwise the 'already_added' protocol error
208 will be raised.
209
210 This request will return a xdg_toplevel_session_v1 for later
211 manipulation. As this resource is created from an empty initial state,
212 compositors must not emit a xdg_toplevel_session_v1.restored event for
213 resources created through this request.
214
215 The name string must be UTF-8 encoded. It is also limited by the maximum
216 length of wayland messages (around 4KB). The 'invalid_name' protocol
217 error will be raised if an invalid string is provided.
218 </description>
219 <arg name="id" type="new_id" interface="xdg_toplevel_session_v1"/>
220 <arg name="toplevel" type="object" interface="xdg_toplevel"/>
221 <arg name="name" type="string" summary="name identifying the toplevel"/>
222 </request>
223
224 <request name="restore_toplevel">
225 <description summary="restore a surface state">
226 Inform the compositor that the toplevel associated with the passed name
227 should have its window management state restored.
228
229 If the toplevel name was previously granted to another xdg_toplevel,
230 the 'name_in_use' protocol error will be raised.
231
232 The toplevel object must not be added more than once to any session
233 created by the client, otherwise the 'already_added' protocol error
234 will be raised.
235
236 This request must be called prior to the first commit on the associated
237 wl_surface after creating the toplevel, otherwise an 'already_mapped'
238 error is raised.
239
240 As part of the initial configure sequence, if the toplevel was
241 successfully restored, a xdg_toplevel_session_v1.restored event is
242 emitted. If the toplevel name was not known in the session, this request
243 will be equivalent to the xdg_toplevel_session_v1.add_toplevel request,
244 and no such event will be emitted. See the xdg_toplevel_session_v1.restored
245 event for further details.
246
247 The name string must be UTF-8 encoded. It is also limited by the maximum
248 length of wayland messages (around 4KB). The 'invalid_name' protocol
249 error will be raised if an invalid string is provided.
250 </description>
251 <arg name="id" type="new_id" interface="xdg_toplevel_session_v1"/>
252 <arg name="toplevel" type="object" interface="xdg_toplevel"/>
253 <arg name="name" type="string" summary="name identifying the toplevel"/>
254 </request>
255
256 <request name="remove_toplevel">
257 <description summary="remove a surface from the session">
258 Remove a specified surface from the session and render any related
259 xdg_toplevel_session_v1 object inert. The compositor should remove any
260 data related to the toplevel in the corresponding session from its internal
261 storage.
262
263 The window is specified by its name in the session. The name string
264 must be encoded in UTF-8, and it is limited in size by the maximum
265 length of wayland messages (around 4KB).
266 </description>
267 <arg name="name" type="string" summary="name identifying the toplevel"/>
268 </request>
269
270 <event name="created">
271 <description summary="newly-created session id">
272 Emitted at most once some time after getting a new session object. It
273 means that no previous state was restored, and a new session was created.
274 The passed id can be persistently stored and used to restore previous
275 sessions.
276 </description>
277 <arg name="session_id" type="string"/>
278 </event>
279
280 <event name="restored">
281 <description summary="the session has been restored">
282 Emitted at most once some time after getting a new session object. It
283 means that previous state was at least partially restored. The same id
284 can again be used to restore previous sessions.
285 </description>
286 </event>
287
288 <event name="replaced">
289 <description summary="the session has been replaced">
290 Emitted at most once, if the session was taken over by some other
291 client. When this happens, the session and all its toplevel session
292 objects become inert, and should be destroyed.
293 </description>
294 </event>
295 </interface>
296
297 <interface name="xdg_toplevel_session_v1" version="1">
298 <description summary="A session for an application">
299 A xdg_toplevel_session_v1 resource acts as a handle for the given
300 toplevel in the session. It allows for receiving events after a
301 toplevel state was restored, and has the requests to manage them.
302 </description>
303
304 <request name="destroy" type="destructor">
305 <description summary="Destroy the object">
306 Destroy the object. This has no effect over window management of the
307 associated toplevel.
308 </description>
309 </request>
310
311 <request name="rename">
312 <description summary="change the name of toplevel session">
313 Renames the toplevel session. The new name can be used in subsequent requests
314 to identify this session object. The state associated with this toplevel
315 session will be preserved.
316
317 If the xdg_session_v1 already contains a toplevel with the specified name,
318 the 'name_in_use' protocol error will be raised.
319 </description>
320 <arg name="name" type="string" summary="new name to identify the toplevel"/>
321 </request>
322
323 <event name="restored">
324 <description summary="a toplevel's session has been restored">
325 The "restored" event is emitted prior to the first
326 xdg_toplevel.configure for the toplevel. It will only be emitted after
327 xdg_session_v1.restore_toplevel, and the initial empty surface state has
328 been applied, and it indicates that the surface's session is being
329 restored with this configure event.
330 </description>
331 </event>
332 </interface>
333</protocol>