build: remove unset X_DISPLAY_MISSING checks

src/lib/Config.h.in

@@ -46,7 +46,4 @@
 /* Define this if the XKB extension is available. */
 #cmakedefine HAVE_XKB_EXTENSION @HAVE_XKB_EXTENSION@
 
-/* Define to 1 if the X Window System is missing or not being used. */
-#cmakedefine X_DISPLAY_MISSING @X_DISPLAY_MISSING@
-
 // clang-format on

src/lib/platform/XWindowsClipboard.h

@@ -14,11 +14,7 @@
 #include <map>
 #include <vector>
 
-#if X_DISPLAY_MISSING
-#error X11 is required to build deskflow
-#else
 #include <X11/Xlib.h>
-#endif
 
 class IXWindowsClipboardConverter;
 

src/lib/platform/XWindowsEventQueueBuffer.h

@@ -12,11 +12,7 @@
 
 #include <vector>
 
-#if X_DISPLAY_MISSING
-#error X11 is required to build deskflow
-#else
 #include <X11/Xlib.h>
-#endif
 
 class IEventQueue;
 

src/lib/platform/XWindowsKeyState.cpp

@@ -20,21 +20,17 @@
 #include "deskflow/ClientArgs.h"
 #include "platform/XWindowsUtil.h"
 
+#include <X11/X.h>
+#include <X11/Xutil.h>
 #include <algorithm>
 #include <cstddef>
 #include <map>
-#if X_DISPLAY_MISSING
-#error X11 is required to build deskflow
-#else
-#include <X11/X.h>
-#include <X11/Xutil.h>
 #define XK_MISCELLANY
 #define XK_XKB_KEYS
 #include <X11/keysymdef.h>
 #if HAVE_XKB_EXTENSION
 #include <X11/XKBlib.h>
 #endif
-#endif
 
 static const size_t ModifiersFromXDefaultSize = 32;
 

src/lib/platform/XWindowsKeyState.h

@@ -12,9 +12,6 @@
 #include <map>
 #include <vector>
 
-#if X_DISPLAY_MISSING
-#error X11 is required to build deskflow
-#else
 #include <X11/Xlib.h>
 #if HAVE_X11_EXTENSIONS_XTEST_H
 #include <X11/extensions/XTest.h>
@@ -24,7 +21,6 @@
 #if HAVE_XKB_EXTENSION
 #include <X11/extensions/XKBstr.h>
 #endif
-#endif
 
 class IEventQueue;
 

src/lib/platform/XWindowsScreen.cpp

@@ -26,14 +26,11 @@
 #include "platform/XWindowsScreenSaver.h"
 #include "platform/XWindowsUtil.h"
 
+#include <X11/X.h>
+#include <X11/Xutil.h>
 #include <algorithm>
 #include <cstdlib>
 #include <cstring>
-#if X_DISPLAY_MISSING
-#error X11 is required to build deskflow
-#else
-#include <X11/X.h>
-#include <X11/Xutil.h>
 #define XK_MISCELLANY
 #define XK_XKB_KEYS
 #include <X11/keysymdef.h>
@@ -64,7 +61,6 @@ extern "C"
 #ifdef HAVE_XI2
 #include <X11/extensions/XInput2.h>
 #endif
-#endif
 
 static int xi_opcode;
 

src/lib/platform/XWindowsScreen.h

@@ -16,11 +16,7 @@
 #include <set>
 #include <vector>
 
-#if X_DISPLAY_MISSING
-#error X11 is required to build deskflow
-#else
 #include <X11/Xlib.h>
-#endif
 
 class XWindowsClipboard;
 class XWindowsKeyState;

src/lib/platform/XWindowsScreenSaver.h

@@ -12,11 +12,7 @@
 
 #include <map>
 
-#if X_DISPLAY_MISSING
-#error X11 is required to build deskflow
-#else
 #include <X11/Xlib.h>
-#endif
 
 class Event;
 class EventQueueTimer;

src/lib/platform/XWindowsUtil.h

@@ -13,11 +13,7 @@
 #include <string>
 #include <vector>
 
-#if X_DISPLAY_MISSING
-#error X11 is required to build deskflow
-#else
 #include <X11/Xlib.h>
-#endif
 
 //! X11 utility functions
 class XWindowsUtil