reset Xorg screensaver on joy events

Use the libXss Xorg screensaver extension library to call
`XResetScreenSaver()` on joystick events to inhibit screen blanking when
for whatever reason the joystick driver or DE (xboxdrv and KDE in this
case) does not do this.
Signed-off-by: Rafael Kitover <rkitover@gmail.com>

src/wx/CMakeLists.txt

@@ -651,6 +651,17 @@ IF( WIN32 )
     ENDIF(ENABLE_DEBUGGER)
 ENDIF( WIN32 )
 
+unset(EXTRA_X11_LIBS)
+if(NOT WIN32 AND NOT APPLE)
+    find_package(X11)
+
+    if(X11_X11_LIB AND X11_Xscreensaver_LIB)
+        include_directories(${X11_INCLUDE_DIR})
+        set(EXTRA_X11_LIBS ${X11_X11_LIB} ${X11_Xscreensaver_LIB})
+        add_definitions(-DHAVE_XSS)
+    endif()
+endif()
+
 link_directories( ${CMAKE_BINARY_DIR} )
 
 SET(VBAM_ICON vbam.icns)
@@ -683,6 +694,7 @@ TARGET_LINK_LIBRARIES (
     ${GTK_LIBRARIES}
     ${OPENAL_LIBRARY}
     ${FAUDIO_LIBS}
+    ${EXTRA_X11_LIBS}
 )
 
 if(ENABLE_FFMPEG)

src/wx/panel.cpp

@@ -1292,6 +1292,14 @@ void GameArea::OnSize(wxSizeEvent& ev)
     ev.Skip(true);
 }
 
+#if defined(__WXGTK__) && defined(HAVE_XSS)
+    #include <X11/Xlib.h>
+    #define Status int
+    #include <X11/extensions/scrnsaver.h>
+    #include <gdk/gdkx.h>
+    #include <gtk/gtk.h>
+#endif
+
 void GameArea::OnSDLJoy(wxSDLJoyEvent& ev)
 {
     int key = ev.GetControlIndex();
@@ -1313,6 +1321,16 @@ void GameArea::OnSDLJoy(wxSDLJoyEvent& ev)
         process_key_press(value & SDL_HAT_LEFT, key, WXJB_HAT_W, joy);
     } else
         process_key_press(ev.GetControlValue() != 0, key, mod, joy);
+
+    // tell Linux to turn off the screensaver/screen-blank if joystick button was pressed
+    // this shouldn't be necessary of course
+#if defined(__WXGTK__) && defined(HAVE_XSS)
+    if (!wxGetApp().UsingWayland()) {
+        Display* display = GDK_WINDOW_XDISPLAY(gtk_widget_get_window(wxGetApp().frame->GetHandle()));
+        XResetScreenSaver(display);
+        XFlush(display);
+    }
+#endif
 }
 
 BEGIN_EVENT_TABLE(GameArea, wxPanel)