meson: Add a Wrap subproject for xcb-keysyms

Add a Wrap subproject definition for the xcb-keysyms dependency. It is
a very simple library with a single C source file, so it is easy to make
Meson build definitions for it that get added on top of the tarball
release fetched by Meson if xcb-keysyms is not available. This way it is
guaranteed that there will be at least some support for keyboard input
if the XKB extension is not available in the X server, or not enabled at
build time.

.gitignore

@@ -0,0 +1,2 @@
+/subprojects/packagecache/
+/subprojects/xcb-util-keysyms-0.4.1/

meson.build

@@ -1,5 +1,5 @@
 project('cog', 'c',
-    meson_version: '>=0.53.2',
+    meson_version: '>=0.55',
     default_options: [
         'buildtype=debugoptimized',
         'b_ndebug=if-release',

platform/x11/cog-platform-x11.c

@@ -20,7 +20,11 @@
 #include <xcb/xcb_cursor.h>
 
 #ifdef COG_X11_USE_XCB_KEYSYMS
-#    include <xcb/xcb_keysyms.h>
+#    if __has_include(<xcb/xcb_keysyms.h>)
+#        include <xcb/xcb_keysyms.h>
+#    else
+#        include <xcb_keysyms.h>
+#    endif
 #endif /* COG_X11_USE_XCB_KEYSYMS */
 
 #ifdef COG_X11_USE_XKB

subprojects/packagefiles/xcb-util-keysyms-0.4.1/meson.build

@@ -0,0 +1,24 @@
+project('xcb-util-keysyms', 'c',
+  version: '0.4.1',
+  default_options: [
+  ],
+)
+
+xcb_dep = dependency('xcb', version: '>=1.4')
+xcb_util_keysyms_dependencies = [xcb_dep, dependency('xproto', version: '>=7.0.8')]
+
+xcb_proto_version = xcb_dep.get_variable('xcbproto_version')
+assert(xcb_proto_version.version_compare('>=1.6'),
+  'libxcb was compiled against xcb-proto @0@, it needs to be compiled against 1.6 or newer'.format(xcb_proto_version))
+
+xcb_util_keysyms_lib = static_library('xcb-util-keysyms',
+  'keysyms/keysyms.c',
+  dependencies: xcb_util_keysyms_dependencies,
+  pic: true,
+)
+
+xcb_util_keysyms_dep = declare_dependency(
+  link_with: xcb_util_keysyms_lib,
+  dependencies: xcb_util_keysyms_dependencies,
+  include_directories: include_directories('keysyms'),
+)

subprojects/xcb-keysyms.wrap

@@ -0,0 +1,9 @@
+[wrap-file]
+directory = xcb-util-keysyms-0.4.1
+source_url = https://xcb.freedesktop.org/dist/xcb-util-keysyms-0.4.1.tar.xz
+source_filename = xcb-util-keysyms-0.4.1.tar.xz
+source_hash = 7c260a5294412aed429df1da2f8afd3bd07b7cba3fec772fba15a613a6d5c638
+patch_directory = xcb-util-keysyms-0.4.1
+
+[provide]
+xcb-keysyms = xcb_util_keysyms_dep