xwaylandproto.txt revision 452262e1 
1                        The XWAYLAND Extension
2			    Version 1.0
3			     2022-07-29
4
51. Introduction
6
7The XWAYLAND extension allows clients to reliably identify whether an X server
8is Xwayland. It does not provide any functionality beyond the absolute minimum
9to identify as extension.
10
11Only Xwayland initializes this extension. Thus, if the extension is present,
12the X server is Xwayland. Clients should not need the protocol detailed in this
13document, a QueryExtension or ListExtensions request is sufficient to check
14whether the extension is present.
15
16The protocol detailed in this document is merely to future-proof this extension
17in case actual functionality is added in the future.
18
19			     ❄ ❄ ❄  ❄  ❄ ❄ ❄
202. Version History
21
22- 1.0, July 2022: QueryVersion request only
23
24			     ❄ ❄ ❄  ❄  ❄ ❄ ❄
25
263. Events and Errors
27
28XWAYLAND defines no events or errrors
29
30			     ❄ ❄ ❄  ❄  ❄ ❄ ❄
31
324. Extension initialization
33
34The name of this extension is "XWAYLAND"
35
36┌───
37   XwlQueryVersion
38	client-major-version:	CARD16
39	client-minor-version:	CARD16
40      ▶
41	major-version:		CARD16
42	minor-version:		CARD16
43└───
44
45	The client sends the highest supported version to the server
46	and the server replies with the highest version it supports,
47	but no higher than the requested version. Major versions changes
48	can introduce incompatibilities in existing functionality, minor
49	version changes introduce only backward compatible changes.
50	It is the clients responsibility to ensure that the server
51	supports a version which is compatible with its expectations.
52
53	Backwards compatible changes include addition of new
54	requests.
55
56			     ❄ ❄ ❄  ❄  ❄ ❄ ❄
57
58Appendix A. Protocol Encoding
59
60Syntactic Conventions
61
62This document uses the same syntactic conventions as the core X
63protocol encoding document.
64
65A.1 Common Types
66
67None.
68
69A.2 Protocol Requests
70
71┌───
72    XwlQueryVersion
73	1	CARD8			major opcode
74	1	0			XWAYLAND opcode
75	2	2			length
76	2	CARD16			major version
77	2	CARD16			minor version
78      ▶
79	1	1			Reply
80	1				unused
81	2	CARD16			sequence number
82	4	0			reply length
83	2	CARD16			major version
84	2	CARD16			minor version
85	20				unused
86└───
87
88A.3 Protocol Events
89
90The XWAYLAND extension defines no events.
91
92A.4 Protocol Errors
93
94The XWAYLAND extension defines no errors.
95
96			     ❄ ❄ ❄  ❄  ❄ ❄ ❄
97