Change properties to have a pending value and report valid values.

Pending values are transferred to current values at mode set, allowing a
queue of values to accrue in preparation for the modeset operation while
still reporting valid 'current' values for applications.

The set of valid values is also available so applications can present
a reasonable list to the user during configuration.

I renumbered a bunch of requests to keep property requests sequential.

3 files changed, 165 insertions, 37 deletions

diff --git a/randr.h b/randr.h
index 935db85..17e6ef9 100644
--- a/randr.h
+++ b/randr.h
@@ -43,7 +43,7 @@ typedef unsigned long	XRandrModeFlags;
 
 #define RRNumberErrors		3
 #define RRNumberEvents		2
-#define RRNumberRequests	23
+#define RRNumberRequests	25
 
 #define X_RRQueryVersion	0
 /* we skip 1 to make old clients fail pretty immediately */
@@ -62,18 +62,20 @@ typedef unsigned long	XRandrModeFlags;
 #define X_RRGetScreenResources	    8
 #define X_RRGetOutputInfo	    9
 #define X_RRListOutputProperties    10
-#define X_RRChangeOutputProperty    11
-#define X_RRDeleteOutputProperty    12
-#define X_RRGetOutputProperty	    13
-#define X_RRCreateMode		    14
-#define X_RRDestroyMode		    15
-#define X_RRAddOutputMode	    16
-#define X_RRDeleteOutputMode	    17
-#define X_RRGetCrtcInfo		    18
-#define X_RRSetCrtcConfig	    19
-#define X_RRGetCrtcGammaSize	    20
-#define X_RRGetCrtcGamma	    21
-#define X_RRSetCrtcGamma	    22
+#define X_RRQueryOutputProperty	    11
+#define X_RRConfigureOutputProperty 12
+#define X_RRChangeOutputProperty    13
+#define X_RRDeleteOutputProperty    14
+#define X_RRGetOutputProperty	    15
+#define X_RRCreateMode		    16
+#define X_RRDestroyMode		    17
+#define X_RRAddOutputMode	    18
+#define X_RRDeleteOutputMode	    19
+#define X_RRGetCrtcInfo		    20
+#define X_RRSetCrtcConfig	    21
+#define X_RRGetCrtcGammaSize	    22
+#define X_RRGetCrtcGamma	    23
+#define X_RRSetCrtcGamma	    24
 
 /* Event selection bits */
 #define RRScreenChangeNotifyMask  (1L << 0)
diff --git a/randrproto.h b/randrproto.h
index 314b9ae..aa9d35f 100644
--- a/randrproto.h
+++ b/randrproto.h
@@ -312,6 +312,44 @@ typedef struct {
     CARD16	length B16;
     RROutput	output B32;
     Atom	property B32;
+} xRRQueryOutputPropertyReq; 
+#define sz_xRRQueryOutputPropertyReq	12
+
+typedef struct {
+    BYTE	type;
+    CARD8	nProperties;
+    CARD16	sequenceNumber B16;
+    CARD32	length B32;
+    BOOL	pending;
+    BOOL	range;
+    BOOL	immutable;
+    BOOL	pad0;
+    CARD16	pad2 B16;
+    CARD32	pad3 B32;
+    CARD32	pad4 B32;
+    CARD32	pad5 B32;
+    CARD32	pad6 B32;
+} xRRQueryOutputPropertyReply;
+#define sz_xRRQueryOutputPropertyReply	32
+
+typedef struct {
+    CARD8	reqType;
+    CARD8	randrReqType;
+    CARD16	length B16;
+    RROutput	output B32;
+    Atom	property B32;
+    BOOL	pending;
+    BOOL	range;
+    CARD16	pad B16;
+} xRRConfigureOutputPropertyReq; 
+#define sz_xRRConfigureOutputPropertyReq	16
+
+typedef struct {
+    CARD8	reqType;
+    CARD8	randrReqType;
+    CARD16	length B16;
+    RROutput	output B32;
+    Atom	property B32;
     Atom	type B32;
     CARD8	format;
     CARD8	mode;
@@ -339,8 +377,8 @@ typedef struct {
     CARD32	longOffset B32;
     CARD32	longLength B32;
     BOOL	delete;
-    CARD8	pad1;
-    CARD16	pad2;
+    BOOL	pending;
+    CARD16	pad1 B16;
 } xRRGetOutputPropertyReq;
 #define sz_xRRGetOutputPropertyReq	28
 
diff --git a/randrproto.txt b/randrproto.txt
index dccee75..c9d0144 100644
--- a/randrproto.txt
+++ b/randrproto.txt
@@ -121,7 +121,7 @@ Andy Ritger for early questions about how mergefb/Xinerama work with RandR
 Carl Worth for editing the specification and Usenix paper
 David Dawes for XFree86 DDX integration work
 Thomas Winischhofer for the hardware-accelerated SiS rotation implementation
-Matthew Tippet and Kevin Martin for splitting outputs and CRTCs to more
+Matthew Tippett and Kevin Martin for splitting outputs and CRTCs to more
 fully expose what video hardware can do
 
                               ❧❧❧❧❧❧❧❧❧❧❧
@@ -609,6 +609,56 @@ dynamic changes in the display environment.
 	the output.
 
 ┌───
+    RRQueryOutputProperty
+	output: OUTPUT
+	property: ATOM
+      ▶
+      	pending: BOOL
+	range: BOOL
+	immutable: BOOL
+	valid-values: LISTofINT32
+└───
+	Errors: Name, Atom, Output
+
+	If the specified property does not exist for the specified output,
+	then a Name error is returned.
+
+	If 'pending' is TRUE, changes made to property values with
+	RRChangeOutputProperty will be saved in the pending property value
+	and be automatically copied to the current value on the next
+	RRSetCrtcConfig request involving the named output. If 'pending' is
+	FALSE, changes are copied immediately.
+	
+	If 'range' is TRUE, then the valid-values list will contain
+	precisely two values indicating the minimum and maximum allowed
+	values. If 'range' is FALSE, then the valid-values list will contain
+	the list of possible values; attempts to set other values will
+	result in a Value error.
+
+	If 'immutable' is TRUE, then the property configuration cannot be
+	changed by clients. Immutable properties are interpreted by the X
+	server.
+	
+┌───
+    RRConfigureOutputProperty
+	output: OUTPUT
+	property: ATOM
+      	pending: BOOL
+	range: BOOL
+	valid-values: LISTofINT32
+└───
+	Errors: Access, Name, Atom, Output
+
+	If the specified property does not exist for the specified output,
+	then a Name error is returned.
+
+	If the specified property is 'immutable', an Access error is
+	returned.
+
+	Otherwise, the configuration of the specified property is changed to
+	the values provided in this request.
+
+┌───
     RRChangeOutputProperty
     	output: OUTPUT
 	property, type: ATOM
@@ -618,10 +668,14 @@ dynamic changes in the display environment.
 └───
 	Errors: Alloc, Atom, Match, Value, Output
 	
-	This request alters the property for the specified output.  The type
-	is uninterpreted by the server.  The format specifies whether the
-	data should be viewed as a list of 8-bit, 16-bit, or 32-bit
-	quantities so that the server can correctly byte-swap as necessary.
+	This request alters the value of the property for the specified
+	output. If the property is marked as a 'pending' property, only the
+	pending value of the property is changed. Otherwise, changes are
+	reflected in both the pending and current values of the property.
+	The type is uninterpreted by the server.  The format specifies
+	whether the data should be viewed as a list of 8-bit, 16-bit, or
+	32-bit quantities so that the server can correctly byte-swap as
+	necessary.
 
 	If the mode is Replace, the previous property value is discarded.
 	If the mode is Prepend or Append, then the type and format must
@@ -659,6 +713,7 @@ dynamic changes in the display environment.
 	type: ATOM or AnyPropertyType
 	long-offset, long-length: CARD32
 	delete: BOOL
+	pending: BOOL
       ▶
 	type: ATOM or None
 	format: {0, 8, 16, 32}
@@ -692,9 +747,11 @@ dynamic changes in the display environment.
 		L = MINIMUM(T, 4 × long-length)
 		A = N - (I + L)
 	
-	The returned value starts at byte index I in the property (indexing
-	from 0), and its length in bytes is L.  However, it is a Value error
-	if long-offset is given such that L is negative.  The value of
+	If 'pending' is true, then the value returned will be the pending
+	value of the property rather than the current value.  The returned
+	value starts at byte index I in the property (indexing from 0), and
+	its length in bytes is L.  However, it is a Value error if
+	long-offset is given such that L is negative.  The value of
 	bytes-after is A, giving the number of trailing unread bytes in the
 	stored property.  If delete is True and the bytes-after is zero, the
 	property is also deleted from the output, and a
@@ -1384,7 +1441,7 @@ A.2.1 Protocol Requests added with version 1.2
     RRListOutputProperties
 	1	CARD8			major opcode
 	1	10			RandR opcode
-	2	3			length
+	2	2			length
 	4	OUTPUT			output
       ▶
 	1	1			Reply
@@ -1396,9 +1453,39 @@ A.2.1 Protocol Requests added with version 1.2
 	4n	LISTofATOM		atoms
 └───
 ┌───
-    RRChangeOutputProperty
+    RRQueryOutputProperty
 	1	CARD8			major opcode
 	1	11			RandR opcode
+	2	3			request length
+	4	OUTPUT			output
+	4	ATOM			property
+      ▶
+	1	1			Reply
+	1				unused
+	2	CARD16			sequence number
+	4	n			reply length
+	1	BOOL			pending
+	1	BOOL			range
+	1	BOOL			immutable
+	21				unused
+	4n	LISTofINT32		valid values
+└───
+┌───
+    RRConfigureOutputProperty
+	1	CARD8			major opcode
+	1	12			RandR opcode
+	2	4+n			request length
+	4	OUTPUT			output
+	4	ATOM			property
+	1	BOOL			pending
+	1	BOOL			range
+	2				unused
+	4n	LISTofINT32		valid values
+└───
+┌───
+    RRChangeOutputProperty
+	1	CARD8			major opcode
+	1	13			RandR opcode
 	2	6+(n+p)/4		request length
 	4	OUTPUT			output
 	4	ATOM			property
@@ -1421,7 +1508,7 @@ A.2.1 Protocol Requests added with version 1.2
 ┌───
     RRDeleteOutputProperty
 	1	CARD8			major opcode
-	1	12			RandR opcode
+	1	14			RandR opcode
 	2	3			request length
 	4	OUTPUT			output
 	4	ATOM			property
@@ -1429,7 +1516,7 @@ A.2.1 Protocol Requests added with version 1.2
 ┌───
     RRGetOutputProperty
 	1	CARD8			major opcode
-	1	13			RandR opcode
+	1	15			RandR opcode
 	2	7			request length
 	4	OUTPUT			output
 	4	ATOM			property
@@ -1438,7 +1525,8 @@ A.2.1 Protocol Requests added with version 1.2
 	4	CARD32			long-offset
 	4	CARD32			long-length
 	1	BOOL			delete
-	3				unused
+	1	BOOL			pending
+	2				unused
       ▶
 	1	1			Reply
 	1	CARD8			format
@@ -1462,7 +1550,7 @@ A.2.1 Protocol Requests added with version 1.2
 ┌───
     RRCreateMode
 	1	CARD8			major opcode
-	1	14			RandR opcode
+	1	16			RandR opcode
 	2	12+(n+p)/4		length
 	4	WINDOW			window
 	32	MODEINFO		mode
@@ -1479,14 +1567,14 @@ A.2.1 Protocol Requests added with version 1.2
 ┌───
     RRDestroyMode
 	1	CARD8			major opcode
-	1	15			RandR opcode
+	1	17			RandR opcode
 	2	2			length
 	4	MODE			mode
 └───
 ┌───
     RRAddOutputMode
 	1	CARD8			major opcode
-	1	16			RandR opcode
+	1	18			RandR opcode
 	2	3			length
 	4	OUTPUT			output
 	4	MODE			mode
@@ -1494,7 +1582,7 @@ A.2.1 Protocol Requests added with version 1.2
 ┌───
     RRDeleteOutputMode
 	1	CARD8			major opcode
-	1	17			RandR opcode
+	1	19			RandR opcode
 	2	3			length
 	4	OUTPUT			output
 	4	MODE			mode
@@ -1502,7 +1590,7 @@ A.2.1 Protocol Requests added with version 1.2
 ┌───
     RRGetCrtcInfo
 	1	CARD8			major opcode
-	1	18			RandR opcode
+	1	20			RandR opcode
 	2	3			length
 	4	CRTC			crtc
 	4	TIMESTAMP		config-timestamp
@@ -1527,7 +1615,7 @@ A.2.1 Protocol Requests added with version 1.2
 ┌───
     RRSetCrtcConfig
 	1	CARD8			major opcode
-	1	19			RandR opcode
+	1	21			RandR opcode
 	2	7+2n			length
 	4	CRTC			crtc
 	4	TIMESTAMP		timestamp
@@ -1549,7 +1637,7 @@ A.2.1 Protocol Requests added with version 1.2
 ┌───
     RRGetCrtcGammaSize
 	1	CARD8			major opcode
-	1	20			RandR opcode
+	1	22			RandR opcode
 	2	2			length
 	4	CRTC			crtc
       ▶
@@ -1563,7 +1651,7 @@ A.2.1 Protocol Requests added with version 1.2
 ┌───
     RRGetCrtcGamma
 	1	CARD8			major opcode
-	1	21			RandR opcode
+	1	23			RandR opcode
 	2	2			length
 	4	CRTC			crtc
       ▶
@@ -1580,7 +1668,7 @@ A.2.1 Protocol Requests added with version 1.2
 ┌───
     RRSetCrtcGamma
 	1	CARD8			major opcode
-	1	22			RandR opcode
+	1	24			RandR opcode
 	2	3+(6n+2)/4		length
 	4	CRTC			crtc
 	2	n			size