Add force_xinerama option

Since after the release a lot of downstream users will not be building
from source, it makes a lot more sense to have an option to fall back to
the Xinerama extension for those that are still on systems that do not
support RandR.

README.md

@@ -17,6 +17,7 @@ Dunst is a highly configurable and lightweight notification daemon.
 Dunst has a number of build dependencies that must be present before attempting configuration. The names are different depending on [distribution](https://github.com/dunst-project/dunst/wiki/Dependencies):
 
 - dbus
+- libxinerama
 - libxrandr
 - libxss
 - libxdg-basedir

config.mk

@@ -32,15 +32,7 @@ CFLAGS   += -g --std=gnu99 -pedantic -Wall -Wno-overlength-strings -Os ${STATIC}
 
 pkg_config_packs := dbus-1 x11 xscrnsaver \
                     "glib-2.0 >= 2.36" gio-2.0 \
-                    pangocairo gdk-2.0
-
-ifeq ($(MULTIMON), xrandr)
-pkg_config_packs += xrandr
-CFLAGS += -DXRANDR
-else ifeq ($(MULTIMON), xinerama)
-pkg_config_packs += xinerama
-CFLAGS += -DXINERAMA
-endif
+                    pangocairo gdk-2.0 xrandr xinerama
 
 # check if we need libxdg-basedir
 ifeq (,$(findstring STATIC_CONFIG,$(CFLAGS)))

docs/dunst.pod

@@ -430,6 +430,16 @@ WM_CLASS). There should be no need to modify this setting for regular use.
 Display a notification on startup. This is usually used for debugging and there
 shouldn't be any need to use this option.
 
+=item B<force_xinerama> (values: [true/false], default: false)
+
+Use the Xinerama extension instead of RandR for multi-monitor support. This
+setting is provided for compatibility with older nVidia drivers that do not
+support RandR and using it on systems that support RandR is highly discouraged.
+
+By enabling this setting dunst will not be able to detect when a monitor is
+connected or disconnected which might break follow mode if the screen layout
+changes.
+
 =back
 
 =head2 Shortcut section

dunstrc

@@ -192,6 +192,18 @@
     # automatically after a crash.
     startup_notification = false
 
+    ### Legacy
+
+    # Use the Xinerama extension instead of RandR for multi-monitor support.
+    # This setting is provided for compatibility with older nVidia drivers that
+    # do not support RandR and using it on systems that support RandR is highly
+    # discouraged.
+    #
+    # By enabling this setting dunst will not be able to detect when a monitor
+    # is connected or disconnected which might break follow mode if the screen
+    # layout changes.
+    force_xinerama = false
+
 # Experimental features that may or may not work correctly. Do not expect them
 # to have a consistent behaviour across releases.
 [experimental]

src/settings.c

@@ -103,6 +103,12 @@ void load_settings(char *cmdline_config_path)
                 ""
         );
 
+        settings.force_xinerama = option_get_bool(
+                "global",
+                "force_xinerama", "-force_xinerama", false,
+                "Force the use of the Xinerama extension"
+        );
+
         settings.font = option_get_string(
                 "global",
                 "font", "-font/-fn", font,

src/settings.h

@@ -70,6 +70,7 @@ typedef struct _settings {
         keyboard_shortcut close_all_ks;
         keyboard_shortcut history_ks;
         keyboard_shortcut context_ks;
+        bool force_xinerama;
 } settings_t;
 
 extern settings_t settings;

src/x11/screen.c

@@ -4,12 +4,9 @@
 #include <X11/Xatom.h>
 #include <X11/Xlib.h>
 #include <X11/Xresource.h>
-#ifdef XRANDR
 #include <X11/extensions/randr.h>
 #include <X11/extensions/Xrandr.h>
-#elif XINERAMA
 #include <X11/extensions/Xinerama.h>
-#endif
 #include <assert.h>
 #include <glib.h>
 #include <locale.h>
@@ -26,7 +23,10 @@ int screens_len;
 
 bool dunst_follow_errored = false;
 
-void x_update_screens_fallback();
+void randr_init();
+void randr_update();
+void xinerama_update();
+void screen_update_fallback();
 static void x_follow_setup_error_handler(void);
 static int x_follow_tear_down_error_handler(void);
 static int FollowXErrorHandler(Display *display, XErrorEvent *e);
@@ -59,6 +59,15 @@ static double get_xft_dpi_value()
         return dpi;
 }
 
+void init_screens() {
+        if (!settings.force_xinerama) {
+                randr_init();
+                randr_update();
+        } else {
+                xinerama_update();
+        }
+}
+
 void alloc_screen_ar(int n)
 {
         assert(n > 0);
@@ -71,27 +80,26 @@ void alloc_screen_ar(int n)
         screens_len = n;
 }
 
-#ifdef XRANDR
 int randr_event_base = 0;
 
-void init_screens()
+void randr_init()
 {
         int randr_error_base = 0;
         if (!XRRQueryExtension(xctx.dpy, &randr_event_base, &randr_error_base)) {
-                fprintf(stderr, "Dunst was compiled with RandR but RandR extension is missing.");
-                exit(1);
+                fprintf(stderr, "Could not initialize the RandR extension, falling back to single monitor mode.\n");
+                return;
         }
         XRRSelectInput(xctx.dpy, RootWindow(xctx.dpy, DefaultScreen(xctx.dpy)), RRScreenChangeNotifyMask);
-        x_update_screens();
 }
 
-void x_update_screens()
+void randr_update()
 {
         int n;
         XRRMonitorInfo *m = XRRGetMonitors(xctx.dpy, RootWindow(xctx.dpy, DefaultScreen(xctx.dpy)), true, &n);
 
-        if (n == -1) {
-                x_update_screens_fallback();
+        if (m == NULL || n == -1) {
+                fprintf(stderr, "(RandR) Could not get screen info, falling back to single monitor mode\n");
+                screen_update_fallback();
                 return;
         }
 
@@ -116,23 +124,17 @@ static int autodetect_dpi(screen_info *scr)
 void screen_check_event(XEvent event)
 {
         if (event.type == randr_event_base + RRScreenChangeNotify)
-                x_update_screens();
+                randr_update();
 }
 
-#elif XINERAMA
-
-void init_screens()
-{
-        x_update_screens();
-}
-
-void x_update_screens()
+void xinerama_update()
 {
         int n;
         XineramaScreenInfo *info = XineramaQueryScreens(xctx.dpy, &n);
 
         if (!info) {
-                x_update_screens_fallback();
+                fprintf(stderr, "(Xinerama) Could not get screen info, falling back to single monitor mode\n");
+                screen_update_fallback();
                 return;
         }
 
@@ -147,29 +149,8 @@ void x_update_screens()
         XFree(info);
 }
 
-void screen_check_event(XEvent event) {} //No-op
 
-#define autodetect_dpi(x) 0
-
-#else
-
-void init_screens()
-{
-        x_update_screens_fallback();
-}
-
-void x_update_screens()
-{
-        x_update_screens_fallback();
-}
-
-void screen_check_event(XEvent event) {} //No-op
-
-#define autodetect_dpi(x) 0
-
-#endif
-
-void x_update_screens_fallback()
+void screen_update_fallback()
 {
         alloc_screen_ar(1);
 

src/x11/screen.h

@@ -22,7 +22,6 @@ typedef struct _screen_info {
 } screen_info;
 
 void init_screens();
-void x_update_screens();
 void screen_check_event(XEvent event);
 
 screen_info *get_active_screen();