Merge branch 'gsoc2010' of git://anongit.freedesktop.org/~chr/libxcb

Makefile.am

@@ -58,6 +58,9 @@ endif
 if BUILD_XINPUT
 pkgconfig_DATA += xcb-xinput.pc
 endif
+if BUILD_XKB
+pkgconfig_DATA += xcb-xkb.pc
+endif
 if BUILD_XPRINT
 pkgconfig_DATA += xcb-xprint.pc
 endif

configure.ac

@@ -146,6 +146,7 @@ XCB_EXTENSION(XFixes, "yes")
 XCB_EXTENSION(XFree86-DRI, "yes")
 XCB_EXTENSION(Xinerama, "yes")
 XCB_EXTENSION(XInput, "no")
+XCB_EXTENSION(XKB, "no")
 XCB_EXTENSION(Xprint, "yes")
 XCB_EXTENSION(SELinux, "no")
 XCB_EXTENSION(XTest, "yes")
@@ -189,6 +190,7 @@ xcb-xf86dri.pc
 xcb-xfixes.pc
 xcb-xinerama.pc
 xcb-xinput.pc
+xcb-xkb.pc
 xcb-xprint.pc
 xcb-xselinux.pc
 xcb-xtest.pc

doc/xkb_internals

@@ -0,0 +1,49 @@
+
+XKB introduces several uncommon data structures:
+ - switch allows conditional inclusion of fields
+ - several complex objects intermix variable and fixed size fields
+ - lists with a variable number of variable size objects
+
+To handle these objects, a number of new functions is generated:
+ - _serialize() turns a structured object into a byte stream, 
+   (re)ordering or including fields according to the protocol
+ - _unserialize() rewrites data from a buffer into a structured object
+ - _unpack() expands a buffer representing a switch object into 
+   a special structured type, all flags needed to resolve the switch
+   expression have to given as parameters
+ - _sizeof() calculates the size of a serialized object, often by calling
+   _unserialize()/_unpack() internally
+
+The new structured data type for switch is special as it contains fixed 
+and variable size fields. Variable size fields can be accessed via pointers. 
+
+If switch appears in a request, an additional set of request helpers is 
+generated with the suffix _aux or _aux_(un)checked. While the 'common'
+request functions require that switch has been serialized before, the _aux
+variants take the structured data type. They are especially designed to 
+replace certain functions in xcb-util/aux. 
+
+Accessors for switch members need two parameters, where the first is usually
+a pointer to the respective request or reply structure, while the second 
+is a pointer to the unpacked switch data structure. 
+
+Functions from the serialize family that take a double pointer can allocate 
+memory on their own, which is useful if the size of a buffer has to be 
+calculated depending on the data within. These functions call malloc() when 
+the double pointer is given as the address of a pointer that has been 
+initialized to 0. It is the responsibility of the user to free any allocated
+memory. 
+
+Intermixed variable and fixed size fields are an important special case in XKB. 
+The current implementation resolves the issue by reordering the fields before
+sending them on the wire as well as before returning a reply. That means that 
+these objects look like 'common' XCB data types and they can be accessed as such 
+(i.e. fixed size fields directly via the structured type and variable size fields
+via accessors/iterators).  
+
+In case a list with variable size elements needs to be accessed, it is necessary 
+to use iterators. The iterator functions take care of determining the actual 
+object size for each element automatically. 
+
+A small and preliminary set of auxiliary functions is available in xkb_util.c 
+in the check_xkb module.  

doc/xkb_issues

@@ -0,0 +1,38 @@
+
+There are a number of problematic special cases in XKB. The issues 
+mentioned here are at most partly resolved.
+ 
+1. The are several XxxDoodad structures defined in xkb.xml. They are used
+   in a few lists, but in a rather special way: 
+   The struct "CommonDoodad" is supposed to be a rather generic data type, 
+   combining the most basic Doodad fields that are common in all these structures. 
+   All Doodads are encapsulated in a union type simply called "Doodad". 
+   Now this union is used in subsequent list definitions, aiming at a kind of 
+   'polymorphism': From inspection of the protocol and Xlib, the Doodads are to 
+   be discriminated based on their type field.
+   However the special meaning of the type field is not encoded in the protocol. 
+   Furthermore the TextDoodad and the LogoDoodad are variable size types due to
+   some fields of type CountedString16, thereby turning the union into a 
+   possibly variable size type as well. 
+   However, for lists with variable size elements, special sizeof functions are 
+   required. These cannot be autogenerated as it cannot be referred which 
+   Doodad type to use for the union. 
+   Therefore, the Doodad type structures are unsupported at the moment. 
+
+2. There are still some bugs in xkb.xml: Either certain fields are missing
+   that are required by the protocol, or Xlib simply has another understanding
+   of the protocol. 
+
+3. The interface for accessors should be reviewed. 
+
+4. Currently some bitcases carry 'name' attributes. These could be avoided if 
+   the data within would consist of a singe struct field only. 
+
+5. switch could get a 'fixed_size' attribute, so when rewriting valueparam to switch, 
+   an uint32_t * pointer could be used instead of void *. 
+
+6. The automatic inclusion of padding requires some complicated coding in the 
+   generator. This is errorprone and could be avoided if all padding is explicitly
+   given in the protocol definition. For variable size fields that require padding, 
+   the pad tag could get a 'fieldref' attribute. That way padding could be handled
+   a lot easier in the autogenerator. 

src/Makefile.am

@@ -168,6 +168,14 @@ libxcb_xinput_la_LIBADD = $(XCB_LIBS)
 nodist_libxcb_xinput_la_SOURCES = xinput.c xinput.h
 endif
 
+EXTSOURCES += xkb.c
+if BUILD_XKB
+lib_LTLIBRARIES += libxcb-xkb.la
+libxcb_xkb_la_LDFLAGS = -version-info 0:0:0 -no-undefined
+libxcb_xkb_la_LIBADD = $(XCB_LIBS)
+nodist_libxcb_xkb_la_SOURCES = xkb.c xkb.h
+endif
+
 EXTSOURCES += xprint.c
 if BUILD_XPRINT
 lib_LTLIBRARIES += libxcb-xprint.la

src/xcb_util.c

@@ -64,6 +64,16 @@ int xcb_popcount(uint32_t mask)
     return ((y + (y >> 3)) & 030707070707) % 077;
 }
 
+int xcb_sumof(uint8_t *list, int len)
+{
+  int i, s = 0;
+  for(i=0; i<len; i++) {
+    s += *list;
+    list++;
+  }
+  return s;
+}
+
 static int _xcb_parse_display(const char *name, char **host, char **protocol,
                       int *displayp, int *screenp)
 {

src/xcbext.h

@@ -86,6 +86,7 @@ int xcb_poll_for_reply(xcb_connection_t *c, unsigned int request, void **reply,
 /* xcb_util.c */
 
 int xcb_popcount(uint32_t mask);
+int xcb_sumof(uint8_t *list, int len);
 
 #ifdef __cplusplus
 }

xcb-xkb.pc.in

@@ -0,0 +1,11 @@
+prefix=@prefix@
+exec_prefix=@exec_prefix@
+libdir=@libdir@
+includedir=@includedir@
+
+Name: XCB XKB
+Description: XCB Keyboard Extension (EXPERIMENTAL)
+Version: @PACKAGE_VERSION@
+Requires: xcb
+Libs: -L${libdir} -lxcb-xkb
+Cflags: -I${includedir}