rdesktop/doc/seamlessrdp-channel.txt

TODO
----

* Command for executing new programs.

* Commands for changing z order and focus.

* Command for transferring icon.

* Think about protocol version management

* Try to assure that messages aren't repeated or are sent for hidden windows.

Overview
========

The protocol is a line based protocol following this simple syntax:

        OPERATION[,ARG1[,ARG2,[...]]]

The goal is to have a generic protocol that can be used for other display
systems (e.g. VNC) as well.

One line may not exceed 1024 bytes, including newline.

The protocol has no concept of hidden or unmapped windows. A window does not
exist unless it is visible. Note that a minimized window is an exception to
this rule.

Data types
==========
Window ID are written in hex, like 0x4321. 

Window positions can be negative. This happens when a window is moved
outside the desktop.

All integers fit inside 32 bits.

Server to Client Operations
===========================

CREATE
------

Allocate structures for a new window.

Syntax:
        CREATE,<ID>,<PARENT>,<FLAGS>

Indicates that a window has appeared on the server. If PARENT is non-zero then
the new window is a child of that window (it's transient for it).

Note that very little information is included in this message. Things like
title and state will come in subsequent messages. This message should only
be used to allocate data structures for the new window.

DESTROY
-------

Remove a window.

Syntax:
        DESTROY,<ID>,<FLAGS>

Remove the window and deallocate all associated structures.

POSITION
--------

Move and/or resize a window.

Syntax:
        POSITION,<ID>,<X>,<Y>,<WIDTH>,<HEIGHT>,<FLAGS>

If the window isn't visible yet (because a
STATE hasn't been set or because it's minimized), you must store the position
and size. A new POSITION is not guaranteed to be sent when the window changes
state.

TITLE
-----

Sets a window title.

Syntax:
        TITLE,<ID>,<TITLE>,<FLAGS>

The text is guaranteed to be stripped of control characters (< 0x20).

Note that this has the same requirement as POSITION, that the title needs to
be stored for newly created windows until a STATE is sent. It is however not
guaranteed that a TITLE will be sent before the first STATE.


ZCHANGE
-------

The window moved in z order.

Syntax:
        ZCHANGE,<ID>,<BEHIND>,<FLAGS>

The window with the id ID is behind the window with the id BEHIND. If
BEHIND is 0, then this window should be brought to the front. 

STATE
-----

Changes the window's state and/or title.

Syntax:
        STATE,<ID>,<STATE>,<FLAGS>

State can have one of three values:
 0 : "Normal" window.
 1 : Minimized.
 2 : Maximized.

The initial STATE for a window will always be preceeded by one CREATE and one
POSITION. Optionally, a TITLE may also be sent before the first STATE.

DEBUG
-----

Debug output from the server component.

Syntax:
        DEBUG,<STRING>

Used for debugging.

SYNCBEGIN
---------

Indicates that a synchronisation has begun.

Syntax:
        SYNCBEGIN,<FLAGS>

Sent when the server starts a synchronisation. The client should flush all
information at this point.

SYNCEND
-------

Indicates that a synchronisation is complete.

Syntac:
        SYNCEND,<FLAGS>

Sent when the last message that is part of the synchronisation has been sent.
This may be followed by duplicate messages and/or messages referring invalid
windows that were queued up during the synchronisation.

Client to Server Operations
===========================

SYNC
----

Request a synchronisation of window information.

Syntax:
        SYNC,<FLAGS>

For each window, the server will send CREATE, POSITION and STATE, in that
order, just as if the window was created. Note that a TITLE may also,
optionally, be sent before the STATE.

POSITION
--------

Identical to the command sent from server to client.

TITLE
-----

Identical to the command sent from server to client.

ZCHANGE
-------

Identical to the command sent from server to client.

STATE
-----

Identical to the command sent from server to client.

FOCUS
-----

Sets which window has input focus.

Syntax:
        FOCUS,<ID>,<FLAGS>

Changes which window that will recieve the keyboard events. Note that this
might cause the window to change z order.
1	astrand	1085	TODO
2			----
3
4			* Command for executing new programs.
5
6			* Commands for changing z order and focus.
7
8			* Command for transferring icon.
9
10			* Think about protocol version management
11
12			* Try to assure that messages aren't repeated or are sent for hidden windows.
13
14			Overview
15			========
16
17			The protocol is a line based protocol following this simple syntax:
18
19			OPERATION[,ARG1[,ARG2,[...]]]
20
21			The goal is to have a generic protocol that can be used for other display
22			systems (e.g. VNC) as well.
23
24			One line may not exceed 1024 bytes, including newline.
25
26			The protocol has no concept of hidden or unmapped windows. A window does not
27	astrand	1092	exist unless it is visible. Note that a minimized window is an exception to
28	astrand	1085	this rule.
29
30			Data types
31			==========
32			Window ID are written in hex, like 0x4321.
33
34			Window positions can be negative. This happens when a window is moved
35			outside the desktop.
36
37			All integers fit inside 32 bits.
38
39			Server to Client Operations
40			===========================
41
42	ossman_	1088	CREATE
43			------
44	astrand	1085
45			Allocate structures for a new window.
46
47			Syntax:
48	ossman_	1095	CREATE,<ID>,<PARENT>,<FLAGS>
49	astrand	1085
50	ossman_	1095	Indicates that a window has appeared on the server. If PARENT is non-zero then
51			the new window is a child of that window (it's transient for it).
52
53	astrand	1085	Note that very little information is included in this message. Things like
54			title and state will come in subsequent messages. This message should only
55			be used to allocate data structures for the new window.
56
57	ossman_	1088	DESTROY
58			-------
59	astrand	1085
60			Remove a window.
61
62			Syntax:
63	ossman_	1088	DESTROY,<ID>,<FLAGS>
64	astrand	1085
65			Remove the window and deallocate all associated structures.
66
67	ossman_	1088	POSITION
68			--------
69	astrand	1085
70	ossman_	1088	Move and/or resize a window.
71	astrand	1085
72			Syntax:
73	ossman_	1088	POSITION,<ID>,<X>,<Y>,<WIDTH>,<HEIGHT>,<FLAGS>
74	astrand	1085
75	ossman_	1088	If the window isn't visible yet (because a
76	astrand	1092	STATE hasn't been set or because it's minimized), you must store the position
77	ossman_	1088	and size. A new POSITION is not guaranteed to be sent when the window changes
78			state.
79	astrand	1085
80	ossman_	1088	TITLE
81			-----
82	astrand	1085
83	ossman_	1088	Sets a window title.
84	astrand	1085
85	ossman_	1088	Syntax:
86			TITLE,<ID>,<TITLE>,<FLAGS>
87
88			The text is guaranteed to be stripped of control characters (< 0x20).
89
90			Note that this has the same requirement as POSITION, that the title needs to
91	ossman_	1126	be stored for newly created windows until a STATE is sent. It is however not
92			guaranteed that a TITLE will be sent before the first STATE.
93	ossman_	1088
94
95			ZCHANGE
96			-------
97
98	astrand	1085	The window moved in z order.
99
100			Syntax:
101	ossman_	1088	ZCHANGE,<ID>,<BEHIND>,<FLAGS>
102	astrand	1085
103			The window with the id ID is behind the window with the id BEHIND. If
104			BEHIND is 0, then this window should be brought to the front.
105
106	ossman_	1088	STATE
107			-----
108	astrand	1085
109			Changes the window's state and/or title.
110
111			Syntax:
112	ossman_	1088	STATE,<ID>,<STATE>,<FLAGS>
113	astrand	1085
114			State can have one of three values:
115			0 : "Normal" window.
116	astrand	1092	1 : Minimized.
117			2 : Maximized.
118	astrand	1085
119	ossman_	1126	The initial STATE for a window will always be preceeded by one CREATE and one
120			POSITION. Optionally, a TITLE may also be sent before the first STATE.
121	astrand	1085
122	ossman_	1088	DEBUG
123			-----
124	astrand	1085
125			Debug output from the server component.
126
127			Syntax:
128	ossman_	1088	DEBUG,<STRING>
129	astrand	1085
130			Used for debugging.
131
132			SYNCBEGIN
133			---------
134
135			Indicates that a synchronisation has begun.
136
137			Syntax:
138			SYNCBEGIN,<FLAGS>
139
140			Sent when the server starts a synchronisation. The client should flush all
141			information at this point.
142
143			SYNCEND
144			-------
145
146			Indicates that a synchronisation is complete.
147
148			Syntac:
149			SYNCEND,<FLAGS>
150
151			Sent when the last message that is part of the synchronisation has been sent.
152			This may be followed by duplicate messages and/or messages referring invalid
153			windows that were queued up during the synchronisation.
154
155			Client to Server Operations
156			===========================
157
158			SYNC
159			----
160
161			Request a synchronisation of window information.
162
163			Syntax:
164			SYNC,<FLAGS>
165
166	ossman_	1126	For each window, the server will send CREATE, POSITION and STATE, in that
167			order, just as if the window was created. Note that a TITLE may also,
168			optionally, be sent before the STATE.
169	ossman_	1088
170			POSITION
171			--------
172
173			Identical to the command sent from server to client.
174
175			TITLE
176			-----
177
178			Identical to the command sent from server to client.
179
180			ZCHANGE
181			-------
182
183			Identical to the command sent from server to client.
184
185			STATE
186			-----
187
188			Identical to the command sent from server to client.
189
190			FOCUS
191			-----
192
193			Sets which window has input focus.
194
195			Syntax:
196			FOCUS,<ID>,<FLAGS>
197
198			Changes which window that will recieve the keyboard events. Note that this
199			might cause the window to change z order.