build: Simplify and clarify X11/Wayland distinction

* Use XDT_CHECK_OPTIONAL_FEATURE
* Only libxtst remains as a truly optional package, and therefore
  HAVE_LIBXTST as a compiler switch, in addition to ENABLE_X11 and
  ENABLE_WAYLAND.

I didn't want to use xfce4-dev-tools 4.19.0 at first, since it's a dev
version, but it seems ok since it's only a build dependency.

Makefile.am

@@ -4,7 +4,7 @@ NULL =
 
 SUBDIRS =
 
-if HAVE_WAYLAND
+if ENABLE_WAYLAND
 SUBDIRS += protocols
 endif
 

autogen.sh

 #!/bin/sh
 
-(type xdt-autogen) >/dev/null 2>&1 || {
+type xdt-autogen >/dev/null 2>&1 || {
   cat >&2 <<EOF
 autogen.sh: You don't seem to have the Xfce development tools installed on
             your system, which are required to build this software.
-            Please install the xfce4-dev-tools package first, available from
-            your distribution or https://www.xfce.org
+            Please install the xfce4-dev-tools package first, it is available
+            from your distribution or https://www.xfce.org/.
 EOF
   exit 1
 }
 
-XDT_AUTOGEN_REQUIRED_VERSION="4.14.0" \
-exec xdt-autogen $@
+XDT_AUTOGEN_REQUIRED_VERSION="4.19.0" exec xdt-autogen "$@"

clipboard-manager/Makefile.am

@@ -13,14 +13,14 @@ libdaemon_la_SOURCES =							\
 	clipboard-manager.c		clipboard-manager.h		\
 	$(NULL)
 
-if HAVE_LIBX11
+if ENABLE_X11
 libdaemon_la_SOURCES += \
 	clipboard-manager-x11.c \
 	clipboard-manager-x11.h \
 	$(NULL)
 endif
 
-if HAVE_WAYLAND
+if ENABLE_WAYLAND
 libdaemon_la_SOURCES += \
 	clipboard-manager-wayland.c \
 	clipboard-manager-wayland.h \
@@ -36,7 +36,7 @@ libdaemon_la_CFLAGS =							\
 
 libdaemon_la_LIBADD =
 
-if HAVE_WAYLAND
+if ENABLE_WAYLAND
 libdaemon_la_LIBADD += \
 	$(top_builddir)/protocols/libprotocols.la
 endif

clipboard-manager/clipboard-manager.c

@@ -20,11 +20,11 @@
 #include <config.h>
 #endif
 
-#ifdef HAVE_LIBX11
+#ifdef ENABLE_X11
 #include <gdk/gdkx.h>
 #include <clipboard-manager/clipboard-manager-x11.h>
 #endif
-#ifdef HAVE_WAYLAND
+#ifdef ENABLE_WAYLAND
 #include <gdk/gdkwayland.h>
 #include <clipboard-manager/clipboard-manager-wayland.h>
 #endif
@@ -52,11 +52,11 @@ xcp_clipboard_manager_get (void)
   if (manager != NULL)
     return g_object_ref (manager);
 
-#ifdef HAVE_LIBX11
+#ifdef ENABLE_X11
   if (GDK_IS_X11_DISPLAY (gdk_display_get_default ()))
     manager = g_object_new (XCP_TYPE_CLIPBOARD_MANAGER_X11, NULL);
 #endif
-#ifdef HAVE_WAYLAND
+#ifdef ENABLE_WAYLAND
   if (GDK_IS_WAYLAND_DISPLAY (gdk_display_get_default ()))
     manager = g_object_new (XCP_TYPE_CLIPBOARD_MANAGER_WAYLAND, NULL);
 #endif

configure.ac.in

@@ -81,26 +81,34 @@ XDT_CHECK_PACKAGE([LIBXFCE4UTIL], [libxfce4util-1.0], [libxfce4util_min_version]
 XDT_CHECK_PACKAGE([LIBXFCE4PANEL], [libxfce4panel-2.0], [libxfce4panel_min_version])
 XDT_CHECK_PACKAGE([XFCONF], [libxfconf-0], [xfconf_min_version])
 
-dnl X11 support
-XDT_CHECK_OPTIONAL_PACKAGE([LIBX11], [x11], [libx11_min_version], [libx11], [Libx11 support])
-XDT_CHECK_OPTIONAL_PACKAGE([GDKX], [gdk-x11-3.0], [gtk_min_version], [gdk-x11], [GDK X11 support])
-XDT_CHECK_OPTIONAL_PACKAGE([LIBXPROTO], [xproto], [libxproto_min_version], [libxproto], [Libxproto support])
-XDT_CHECK_OPTIONAL_PACKAGE([LIBXTST], [xtst], [libxtst_min_version], [libxtst], [Libxtst support])
-
-dnl Wayland support
-dnl wayland-scanner >= 1.15 is for private-code option to be present
-XDT_CHECK_OPTIONAL_PACKAGE([WAYLAND_SCANNER], [wayland-scanner], [wayland_min_version], [wayland-scanner], [Wayland scanner support])
-XDT_CHECK_OPTIONAL_PACKAGE([WAYLAND_CLIENT], [wayland-client], [wayland_min_version], [wayland-client], [Wayland client support])
-XDT_CHECK_OPTIONAL_PACKAGE([GDKW], [gdk-wayland-3.0], [gtk_min_version], [gdk-wayland], [GDK Wayland support])
-if test x"$WAYLAND_SCANNER_FOUND" = x"yes" && test x"$WAYLAND_CLIENT_FOUND" = x"yes" && test x"$GDKW_FOUND" = x"yes"; then
-  WAYLAND_FOUND="yes"
-  AC_DEFINE([HAVE_WAYLAND], [1], [Wayland support])
+dnl ***********************************
+dnl *** Check for optional packages ***
+dnl ***********************************
+XDT_CHECK_OPTIONAL_FEATURE([X11],
+                           [x11],
+                           [
+                             XDT_FEATURE_DEPENDENCY([LIBX11], [x11], [libx11_min_version])
+                             XDT_FEATURE_DEPENDENCY([GDK_X11], [gdk-x11-3.0], [gtk_min_version])
+                             XDT_FEATURE_DEPENDENCY([LIBXPROTO], [xproto], [libxproto_min_version])
+                           ],
+                           [the X11 windowing system])
+XDT_CHECK_OPTIONAL_FEATURE([WAYLAND],
+                           [wayland],
+                           [
+                             XDT_FEATURE_DEPENDENCY([GDK_WAYLAND], [gdk-wayland-3.0], [gtk_min_version])
+                             XDT_FEATURE_DEPENDENCY([WAYLAND_SCANNER], [wayland-scanner], [wayland_min_version])
+                             XDT_FEATURE_DEPENDENCY([WAYLAND_CLIENT], [wayland-client], [wayland_min_version])
+                           ],
+                           [the Wayland windowing system])
+if test x"$ENABLE_X11" != x"yes" -a x"$ENABLE_WAYLAND" != x"yes"; then
+  AC_MSG_ERROR([Either both X11 and Wayland support was disabled, or required dependencies are missing. One of the two must be enabled.])
 fi
-AM_CONDITIONAL([HAVE_WAYLAND], [test x"$WAYLAND_SCANNER_FOUND" = x"yes" && test x"$WAYLAND_CLIENT_FOUND" = x"yes" && test x"$GDKW_FOUND" = x"yes"])
+if test x"$ENABLE_X11" != x"yes"; then
+  dnl Do not check for optional X11 packages if X11 is disabled
+  enable_libxtst=no
+fi
+XDT_CHECK_OPTIONAL_PACKAGE([LIBXTST], [xtst], [libxtst_min_version], [libxtst], [Libxtst support])
 
-dnl *****************************
-dnl *** Check for libqrencode ***
-dnl *****************************
 XDT_CHECK_OPTIONAL_PACKAGE([QRENCODE], [libqrencode], [libqrencode_min_version], libqrencode, [QR Code support])
 
 dnl ******************************
@@ -141,9 +149,11 @@ dnl ***************************
 echo
 echo "Build Configuration:"
 echo
-echo "    * Debug Support:    $enable_debug"
-echo "    * X11 Support:      ${LIBX11_FOUND:-no}"
-echo "    * Libxtst Support:  ${LIBXTST_FOUND:-no}"
-echo "    * Wayland Support:  ${WAYLAND_FOUND:-no}"
-echo "    * QR Code Support:  ${QRENCODE_FOUND:-no}"
+echo "* Debug Support:      $enable_debug"
+echo "* X11 Support:        ${ENABLE_X11:-no}"
+if test x"$ENABLE_X11" = x"yes"; then
+echo "  * Libxtst Support:  ${LIBXTST_FOUND:-no}"
+fi
+echo "* Wayland Support:    ${ENABLE_WAYLAND:-no}"
+echo "* QR Code Support:    ${QRENCODE_FOUND:-no}"
 echo

panel-plugin/Makefile.am

@@ -12,7 +12,7 @@ AM_CPPFLAGS =								\
 
 bin_PROGRAMS = xfce4-popup-clipman xfce4-clipman-settings xfce4-clipman-history
 
-if HAVE_LIBX11
+if ENABLE_X11
 bin_PROGRAMS += xfce4-clipman
 endif
 
@@ -40,7 +40,6 @@ xfce4_popup_clipman_CFLAGS =                                            \
 	-DGSEAL_ENABLE							\
 	@LIBX11_CFLAGS@							\
 	@LIBXTST_CFLAGS@						\
-	@GDKX_CFLAGS@							\
 	@GTK_CFLAGS@							\
 	@LIBXFCE4UI_CFLAGS@						\
 	$(NULL)
@@ -48,7 +47,6 @@ xfce4_popup_clipman_CFLAGS =                                            \
 xfce4_popup_clipman_LDADD =						\
 	@LIBX11_LIBS@							\
 	@LIBXTST_LIBS@							\
-	@GDKX_LIBS@							\
 	@GTK_LIBS@							\
 	@LIBXFCE4UI_LIBS@						\
 	$(NULL)
@@ -73,7 +71,6 @@ xfce4_clipman_history_CFLAGS =                                            \
 	@LIBX11_CFLAGS@							\
 	@LIBXTST_CFLAGS@						\
 	@GIO_CFLAGS@							\
-	@GDKX_CFLAGS@							\
 	@GTK_CFLAGS@							\
 	@LIBXFCE4UTIL_CFLAGS@					\
 	@LIBXFCE4UI_CFLAGS@						\
@@ -85,7 +82,6 @@ xfce4_clipman_history_LDADD =						\
 	@LIBX11_LIBS@							\
 	@LIBXTST_LIBS@							\
 	@GIO_LIBS@							\
-	@GDKX_LIBS@							\
 	@GTK_LIBS@							\
 	@LIBXFCE4UTIL_LIBS@						\
 	@LIBXFCE4UI_LIBS@						\
@@ -125,7 +121,7 @@ xfce4_clipman_settings_LDADD =						\
 # Status Icon
 #
 
-if HAVE_LIBX11
+if ENABLE_X11
 
 xfce4_clipman_SOURCES =							\
 	main-status-icon.c						\
@@ -143,7 +139,6 @@ xfce4_clipman_CFLAGS =							\
 	@GIO_CFLAGS@							\
 	@LIBX11_CFLAGS@							\
 	@LIBXTST_CFLAGS@						\
-	@GDKX_CFLAGS@							\
 	@GTK_CFLAGS@							\
 	@LIBXFCE4UTIL_CFLAGS@					\
 	@LIBXFCE4UI_CFLAGS@						\
@@ -155,7 +150,6 @@ xfce4_clipman_LDADD =							\
 	@GIO_LIBS@							\
 	@LIBX11_LIBS@							\
 	@LIBXTST_LIBS@							\
-	@GDKX_LIBS@							\
 	@GTK_LIBS@							\
 	@LIBXFCE4UTIL_LIBS@						\
 	@LIBXFCE4UI_LIBS@						\
@@ -187,7 +181,6 @@ libclipman_la_CFLAGS =							\
 	@GIO_CFLAGS@							\
 	@LIBX11_CFLAGS@							\
 	@LIBXTST_CFLAGS@						\
-	@GDKX_CFLAGS@							\
 	@GTK_CFLAGS@							\
 	@LIBXFCE4UTIL_CFLAGS@					\
 	@LIBXFCE4UI_CFLAGS@						\
@@ -209,7 +202,6 @@ libclipman_la_LIBADD =							\
 	@GIO_LIBS@							\
 	@LIBX11_LIBS@							\
 	@LIBXTST_LIBS@							\
-	@GDKX_LIBS@							\
 	@GTK_LIBS@							\
 	@LIBXFCE4UTIL_LIBS@						\
 	@LIBXFCE4UI_LIBS@						\
@@ -238,7 +230,7 @@ plugins_DATA = $(plugins_in_files:.desktop.in=.desktop)
 
 appsdir = $(datadir)/applications
 apps_in_files = xfce4-clipman-settings.desktop.in
-if HAVE_LIBX11
+if ENABLE_X11
 apps_in_files += xfce4-clipman.desktop.in
 endif
 apps_DATA = $(apps_in_files:.desktop.in=.desktop)
@@ -248,7 +240,7 @@ apps_DATA = $(apps_in_files:.desktop.in=.desktop)
 # Autostart File
 #
 
-if HAVE_LIBX11
+if ENABLE_X11
 
 autostartdir = $(sysconfdir)/xdg/autostart
 autostart_in_files = xfce4-clipman-plugin-autostart.desktop.in

panel-plugin/common.h

@@ -26,13 +26,13 @@
 #define __CLIPMAN_COMMON_H__
 
 #include <gdk/gdk.h>
-#ifdef GDK_WINDOWING_X11
+#ifdef ENABLE_X11
 #include <gdk/gdkx.h>
 #define WINDOWING_IS_X11() GDK_IS_X11_DISPLAY (gdk_display_get_default ())
 #else
 #define WINDOWING_IS_X11() FALSE
 #endif
-#ifdef GDK_WINDOWING_WAYLAND
+#ifdef ENABLE_WAYLAND
 #include <gdk/gdkwayland.h>
 #define WINDOWING_IS_WAYLAND() GDK_IS_WAYLAND_DISPLAY (gdk_display_get_default ())
 #else