Remove need for --enable-multitouch

If we spot inputproto 2.1.99.3, we assume we have a capable X server. This
should really be a server version check, but the server version hasn't been
bumped yet.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

configure.ac

@@ -48,16 +48,11 @@ XORG_DEFAULT_OPTIONS
 PKG_CHECK_MODULES(XORG, [xorg-server >= 1.10] xproto inputproto)
 PKG_CHECK_MODULES(UDEV, udev)
 
-# Whether to include support for experimental XI 2.2 multitouch
-AC_ARG_ENABLE(multitouch,
-              AC_HELP_STRING([--enable-multitouch],
-                             [Enable experimental XI 2.2 multitouch support [[default: disabled]]]),
-              [MULTITOUCH=$enableval],
-              [MULTITOUCH=no])
-
-if test "x$MULTITOUCH" = xyes; then
-        AC_DEFINE(MULTITOUCH, 1, [Enable experimental multitouch code])
+PKG_CHECK_MODULES(XI22, [inputproto >= 2.1.99.3],
+                  HAVE_XI22="yes"; AC_DEFINE(MULTITOUCH, 1, [XI2.2 available]),
+                  HAVE_XI22="no")
 
+if test "x$HAVE_XI22" = xyes; then
         # Obtain compiler/linker options for mtdev
         PKG_CHECK_MODULES(MTDEV, mtdev)
 fi

src/evdev.h

@@ -43,6 +43,17 @@
 #include <xf86_OSproc.h>
 #include <xkbstr.h>
 
+/* FIXME: once the server version is bumped, we can remove this with a
+ * proper pkg-config check. Right now we need an inputproto check for
+ * the right protocol, the pkgconfig check for the mtdev pkgconfig, and an
+ * ABI check to undo the first two if the proto was updated but the server
+ * wasn't yet */
+#ifdef MULTITOUCH
+#if GET_ABI_MAJOR(ABI_XINPUT_VERSION) < 16
+#undef MULTITOUCH
+#endif
+#endif
+
 #ifdef MULTITOUCH
 #include <mtdev.h>
 #endif