Rework and consolidate monitor handling in MetaScreen

Consolidate all places that deal with output configuration in
MetaScreen, which gets it either from XRandR or from a dummy static configuration.
We still need to read the Xinerama config, even when running xwayland,
because we need the indices for _NET_WM_FULLSCREEN_MONITORS, but
now we do it only when needed.

https://bugzilla.gnome.org/show_bug.cgi?id=705670

7 files changed, 563 insertions, 252 deletions

diff --git a/src/Makefile.am b/src/Makefile.am
index 5f2b10dd6..2755d15f3 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -110,6 +110,8 @@ libmutter_la_SOURCES =				\
 	core/keybindings.c			\
 	core/keybindings-private.h		\
 	core/main.c				\
+	core/monitor.c				\
+	core/monitor-private.h			\
 	core/mutter-Xatomtype.h			\
 	core/place.c				\
 	core/place.h				\
diff --git a/src/core/monitor-private.h b/src/core/monitor-private.h
new file mode 100644
index 000000000..bc1ee25e1
--- /dev/null
+++ b/src/core/monitor-private.h
@@ -0,0 +1,97 @@
+/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
+
+/**
+ * \file screen-private.h  Handling of monitor configuration
+ *
+ * Managing multiple monitors
+ * This file contains structures and functions that handle
+ * multiple monitors, including reading the current configuration
+ * and available hardware, and applying it.
+ *
+ * This interface is private to mutter, API users should look
+ * at MetaScreen instead.
+ */
+
+/* 
+ * Copyright (C) 2001 Havoc Pennington
+ * Copyright (C) 2003 Rob Adams
+ * Copyright (C) 2004-2006 Elijah Newren
+ * Copyright (C) 2013 Red Hat Inc.
+ * 
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ */
+
+#ifndef META_MONITOR_PRIVATE_H
+#define META_MONITOR_PRIVATE_H
+
+#include "display-private.h"
+#include <meta/screen.h>
+#include "stack-tracker.h"
+#include "ui.h"
+
+#include <cogl/cogl.h>
+
+typedef struct _MetaOutput MetaOutput;
+typedef struct _MetaMonitorInfo MetaMonitorInfo;
+
+struct _MetaOutput
+{
+  MetaMonitorInfo *monitor;
+  char *name;
+  int width_mm;
+  int height_mm;
+  CoglSubpixelOrder subpixel_order;
+};
+
+struct _MetaMonitorInfo
+{
+  int number;
+  int xinerama_index;
+  MetaRectangle rect;
+  gboolean is_primary;
+  gboolean in_fullscreen;
+  float refresh_rate;
+
+  /* The primary or first output for this crtc, 0 if we can't figure out. */
+  glong output_id;
+};
+
+#define META_TYPE_MONITOR_MANAGER            (meta_monitor_manager_get_type ())
+#define META_MONITOR_MANAGER(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), META_TYPE_MONITOR_MANAGER, MetaMonitorManager))
+#define META_MONITOR_MANAGER_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass),  META_TYPE_MONITOR_MANAGER, MetaMonitorManagerClass))
+#define META_IS_MONITOR_MANAGER(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), META_TYPE_MONITOR_MANAGER))
+#define META_IS_MONITOR_MANAGER_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass),  META_TYPE_MONITOR_MANAGER))
+#define META_MONITOR_MANAGER_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj),  META_TYPE_MONITOR_MANAGER, MetaMonitorManagerClass))
+
+typedef struct _MetaMonitorManagerClass    MetaMonitorManagerClass;
+typedef struct _MetaMonitorManager         MetaMonitorManager;
+
+GType meta_monitor_manager_get_type (void);
+
+void                meta_monitor_manager_initialize (Display *display);
+MetaMonitorManager *meta_monitor_manager_get  (void);
+
+MetaMonitorInfo    *meta_monitor_manager_get_monitor_infos (MetaMonitorManager *manager,
+							    int                *n_infos);
+
+MetaOutput         *meta_monitor_manager_get_outputs       (MetaMonitorManager *manager,
+							    int                *n_outputs);
+
+int                 meta_monitor_manager_get_primary_index (MetaMonitorManager *manager);
+
+void                meta_monitor_manager_invalidate        (MetaMonitorManager *manager);
+
+#endif
diff --git a/src/core/monitor.c b/src/core/monitor.c
new file mode 100644
index 000000000..05d4f2b41
--- /dev/null
+++ b/src/core/monitor.c
@@ -0,0 +1,356 @@
+/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
+
+/* 
+ * Copyright (C) 2001, 2002 Havoc Pennington
+ * Copyright (C) 2002, 2003 Red Hat Inc.
+ * Some ICCCM manager selection code derived from fvwm2,
+ * Copyright (C) 2001 Dominik Vogt, Matthias Clasen, and fvwm2 team
+ * Copyright (C) 2003 Rob Adams
+ * Copyright (C) 2004-2006 Elijah Newren
+ * Copyright (C) 2013 Red Hat Inc.
+ * 
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+ * 02111-1307, USA.
+ */
+
+#include "config.h"
+
+#include <clutter/clutter.h>
+
+#ifdef HAVE_RANDR
+#include <X11/extensions/Xrandr.h>
+#endif
+
+#include "monitor-private.h"
+
+struct _MetaMonitorManager
+{
+  GObject parent_instance;
+
+  /* Outputs refers to physical screens,
+     while monitor_infos refer to logical ones (aka CRTC)
+     They can be different if two outputs are
+     in clone mode
+  */
+  MetaOutput *outputs;
+  int primary_monitor_index;
+  int n_outputs;
+
+  MetaMonitorInfo *monitor_infos;
+  int n_monitor_infos;
+
+#ifdef HAVE_RANDR
+  Display *xdisplay;
+#endif
+};
+
+struct _MetaMonitorManagerClass
+{
+  GObjectClass parent_class;
+};
+
+enum {
+  MONITORS_CHANGED,
+  SIGNALS_LAST
+};
+
+static int signals[SIGNALS_LAST];
+
+G_DEFINE_TYPE (MetaMonitorManager, meta_monitor_manager, G_TYPE_OBJECT);
+
+static void
+make_dummy_monitor_config (MetaMonitorManager *manager)
+{
+  manager->monitor_infos = g_new0 (MetaMonitorInfo, 1);
+  manager->n_monitor_infos = 1;
+
+  manager->monitor_infos[0].number = 0;
+  manager->monitor_infos[0].xinerama_index = 0;
+  manager->monitor_infos[0].rect.x = 0;
+  manager->monitor_infos[0].rect.y = 0;
+  if (manager->xdisplay)
+    {
+      Screen *screen = ScreenOfDisplay (manager->xdisplay,
+                                        DefaultScreen (manager->xdisplay));
+
+      manager->monitor_infos[0].rect.width = WidthOfScreen (screen);
+      manager->monitor_infos[0].rect.height = HeightOfScreen (screen);
+    }
+  else
+    {
+      manager->monitor_infos[0].rect.width = 1024;
+      manager->monitor_infos[0].rect.height = 768;
+    }
+  manager->monitor_infos[0].refresh_rate = 60.0f;
+  manager->monitor_infos[0].is_primary = TRUE;
+  manager->monitor_infos[0].in_fullscreen = -1;
+  manager->monitor_infos[0].output_id = 1;
+
+  manager->outputs = g_new0 (MetaOutput, 1);
+  manager->n_outputs = 1;
+
+  manager->outputs[0].monitor = &manager->monitor_infos[0];
+  manager->outputs[0].name = g_strdup ("LVDS");
+  manager->outputs[0].width_mm = 222;
+  manager->outputs[0].height_mm = 125;
+  manager->outputs[0].subpixel_order = COGL_SUBPIXEL_ORDER_UNKNOWN;
+}
+
+#ifdef HAVE_RANDR
+
+/* In the case of multiple outputs of a single crtc (mirroring), we consider one of the
+ * outputs the "main". This is the one we consider "owning" the windows, so if
+ * the mirroring is changed to a dual monitor setup then the windows are moved to the
+ * crtc that now has that main output. If one of the outputs is the primary that is
+ * always the main, otherwise we just use the first.
+ */
+static void
+find_main_output_for_crtc (MetaMonitorManager         *manager,
+                           XRRScreenResources *resources,
+                           XRRCrtcInfo        *crtc,
+                           MetaMonitorInfo    *info,
+                           GArray             *outputs)
+{
+  XRROutputInfo *output;
+  RROutput primary_output;
+  int i;
+
+  primary_output = XRRGetOutputPrimary (manager->xdisplay,
+                                        DefaultRootWindow (manager->xdisplay));
+
+  for (i = 0; i < crtc->noutput; i++)
+    {
+      output = XRRGetOutputInfo (manager->xdisplay, resources, crtc->outputs[i]);
+
+      if (output->connection != RR_Disconnected)
+        {
+          MetaOutput meta_output;
+
+          meta_output.name = g_strdup (output->name);
+          meta_output.width_mm = output->mm_width;
+          meta_output.height_mm = output->mm_height;
+          meta_output.subpixel_order = COGL_SUBPIXEL_ORDER_UNKNOWN;
+
+          g_array_append_val (outputs, meta_output);
+
+          if (crtc->outputs[i] == primary_output)
+            {
+              info->output_id = crtc->outputs[i];
+              info->is_primary = TRUE;
+              manager->primary_monitor_index = info->number;
+            }
+          else if (info->output_id == 0)
+            {
+              info->output_id = crtc->outputs[i];
+            }
+        }
+
+      XRRFreeOutputInfo (output);
+    }
+}
+
+static void
+read_monitor_infos_from_xrandr (MetaMonitorManager *manager)
+{
+    XRRScreenResources *resources;
+    GArray *outputs;
+    int i, j;
+
+    resources = XRRGetScreenResourcesCurrent (manager->xdisplay,
+                                              DefaultRootWindow (manager->xdisplay));
+    if (!resources)
+      return make_dummy_monitor_config (manager);
+
+    outputs = g_array_new (FALSE, TRUE, sizeof (MetaOutput));
+
+    manager->n_outputs = 0;
+    manager->n_monitor_infos = resources->ncrtc;
+
+    manager->monitor_infos = g_new0 (MetaMonitorInfo, manager->n_monitor_infos);
+
+    for (i = 0; i < resources->ncrtc; i++)
+      {
+        XRRCrtcInfo *crtc;
+        MetaMonitorInfo *info;
+
+        crtc = XRRGetCrtcInfo (manager->xdisplay, resources, resources->crtcs[i]);
+
+        info = &manager->monitor_infos[i];
+
+        info->number = i;
+        info->rect.x = crtc->x;
+        info->rect.y = crtc->y;
+        info->rect.width = crtc->width;
+        info->rect.height = crtc->height;
+        info->in_fullscreen = -1;
+
+        for (j = 0; j < resources->nmode; j++)
+          {
+            if (resources->modes[j].id == crtc->mode)
+              info->refresh_rate = (resources->modes[j].dotClock /
+                                    ((float)resources->modes[j].hTotal *
+                                     resources->modes[j].vTotal));
+          }
+
+        find_main_output_for_crtc (manager, resources, crtc, info, outputs);
+
+        XRRFreeCrtcInfo (crtc);
+      }
+
+    manager->n_outputs = outputs->len;
+    manager->outputs = (void*)g_array_free (outputs, FALSE);
+
+    XRRFreeScreenResources (resources);
+}
+
+#endif
+
+/*
+ * meta_has_dummy_output:
+ *
+ * Returns TRUE if the only available monitor is the dummy one
+ * backing the ClutterStage window.
+ */
+static gboolean
+has_dummy_output (void)
+{
+  return FALSE;
+}
+
+static void
+meta_monitor_manager_init (MetaMonitorManager *manager)
+{
+}
+
+static void
+read_current_config (MetaMonitorManager *manager)
+{
+  if (has_dummy_output ())
+    return make_dummy_monitor_config (manager);
+
+#ifdef HAVE_RANDR
+  return read_monitor_infos_from_xrandr (manager);
+#endif
+}
+
+static MetaMonitorManager *
+meta_monitor_manager_new (Display *display)
+{
+  MetaMonitorManager *manager;
+
+  manager = g_object_new (META_TYPE_MONITOR_MANAGER, NULL);
+
+  manager->xdisplay = display;
+
+  read_current_config (manager);
+  return manager;
+}
+
+static void
+free_output_array (MetaOutput *old_outputs,
+                   int         n_old_outputs)
+{
+  int i;
+
+  for (i = 0; i < n_old_outputs; i++)
+    g_free (old_outputs[i].name);
+  g_free (old_outputs);
+}
+
+static void
+meta_monitor_manager_finalize (GObject *object)
+{
+  MetaMonitorManager *manager = META_MONITOR_MANAGER (object);
+
+  free_output_array (manager->outputs, manager->n_outputs);
+  g_free (manager->monitor_infos);
+
+  G_OBJECT_CLASS (meta_monitor_manager_parent_class)->finalize (object);
+}
+
+static void
+meta_monitor_manager_class_init (MetaMonitorManagerClass *klass)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+  object_class->finalize = meta_monitor_manager_finalize;
+
+  signals[MONITORS_CHANGED] =
+    g_signal_new ("monitors-changed",
+		  G_TYPE_FROM_CLASS (object_class),
+		  G_SIGNAL_RUN_LAST,
+		  0,
+                  NULL, NULL, NULL,
+		  G_TYPE_NONE, 0);
+}
+
+static MetaMonitorManager *global_manager;
+
+void
+meta_monitor_manager_initialize (Display *display)
+{
+  global_manager = meta_monitor_manager_new (display);
+}
+
+MetaMonitorManager *
+meta_monitor_manager_get (void)
+{
+  g_assert (global_manager != NULL);
+
+  return global_manager;
+}
+
+MetaMonitorInfo *
+meta_monitor_manager_get_monitor_infos (MetaMonitorManager *manager,
+                                        int                *n_infos)
+{
+  *n_infos = manager->n_monitor_infos;
+  return manager->monitor_infos;
+}
+
+MetaOutput *
+meta_monitor_manager_get_outputs (MetaMonitorManager *manager,
+                                  int                *n_outputs)
+{
+  *n_outputs = manager->n_outputs;
+  return manager->outputs;
+}
+
+int
+meta_monitor_manager_get_primary_index (MetaMonitorManager *manager)
+{
+  return manager->primary_monitor_index;
+}
+
+void
+meta_monitor_manager_invalidate (MetaMonitorManager *manager)
+{
+  MetaOutput *old_outputs;
+  MetaMonitorInfo *old_monitor_infos;
+  int n_old_outputs;
+
+  /* Save the old monitor infos, so they stay valid during the update */
+  old_outputs = manager->outputs;
+  n_old_outputs = manager->n_outputs;
+  old_monitor_infos = manager->monitor_infos;
+
+  read_current_config (manager);
+
+  g_signal_emit (manager, signals[MONITORS_CHANGED], 0);
+
+  g_free (old_monitor_infos);
+  free_output_array (old_outputs, n_old_outputs);
+}
+
diff --git a/src/core/screen-private.h b/src/core/screen-private.h
index 83adb8317..894eda5e4 100644
--- a/src/core/screen-private.h
+++ b/src/core/screen-private.h
@@ -38,17 +38,7 @@
 #include <X11/Xutil.h>
 #include "stack-tracker.h"
 #include "ui.h"
-
-typedef struct _MetaMonitorInfo MetaMonitorInfo;
-
-struct _MetaMonitorInfo
-{
-  int number;
-  MetaRectangle rect;
-  gboolean is_primary;
-  gboolean in_fullscreen;
-  XID output; /* The primary or first output for this crtc, None if no xrandr */
-};
+#include "monitor-private.h"
 
 typedef void (* MetaScreenWindowFunc) (MetaScreen *screen, MetaWindow *window,
                                        gpointer user_data);
@@ -100,10 +90,11 @@ struct _MetaScreen
   Window wm_sn_selection_window;
   Atom wm_sn_atom;
   guint32 wm_sn_timestamp;
-  
+
   MetaMonitorInfo *monitor_infos;
-  int primary_monitor_index;
   int n_monitor_infos;
+  int primary_monitor_index;
+  gboolean has_xinerama_indices;
 
   /* Cache the current monitor */
   int last_monitor_index;
@@ -257,4 +248,9 @@ void     meta_screen_workspace_switched (MetaScreen         *screen,
 
 void meta_screen_set_active_workspace_hint (MetaScreen *screen);
 
+int meta_screen_xinerama_index_to_monitor_index (MetaScreen *screen,
+                                                 int         index);
+int meta_screen_monitor_index_to_xinerama_index (MetaScreen *screen,
+                                                 int         index);
+
 #endif
diff --git a/src/core/screen.c b/src/core/screen.c
index 6db3ea385..cb02f201b 100644
--- a/src/core/screen.c
+++ b/src/core/screen.c
@@ -48,10 +48,6 @@
 
 #include <X11/extensions/Xinerama.h>
 
-#ifdef HAVE_RANDR
-#include <X11/extensions/Xrandr.h>
-#endif
-
 #include <X11/Xatom.h>
 #include <locale.h>
 #include <string.h>
@@ -76,6 +72,9 @@ static void meta_screen_sn_event   (SnMonitorEvent *event,
                                     void           *user_data);
 #endif
 
+static void on_monitors_changed (MetaMonitorManager *manager,
+                                 MetaScreen         *screen);
+
 enum
 {
   PROP_N_WORKSPACES = 1,
@@ -350,250 +349,93 @@ set_wm_icon_size_hint (MetaScreen *screen)
 #undef N_VALS
 }
 
-/* The list of monitors reported by the windowing system might include
- * mirrored monitors with identical bounds. Since mirrored monitors
- * shouldn't be treated as separate monitors for most purposes, we
- * filter them out here. (We ignore the possibility of partially
- * overlapping monitors because they are rare and it's hard to come
- * up with any sensible interpretation.)
- */
 static void
-filter_mirrored_monitors (MetaScreen *screen)
+meta_screen_ensure_xinerama_indices (MetaScreen *screen)
 {
-  int i, j;
+  XineramaScreenInfo *infos;
+  int n_infos, i, j;
 
-  /* Currently always true and simplifies things */
-  g_assert (screen->primary_monitor_index == 0);
+  if (screen->has_xinerama_indices)
+    return;
+
+  screen->has_xinerama_indices = TRUE;
 
-  for (i = 1; i < screen->n_monitor_infos; i++)
+  if (!XineramaIsActive (screen->display->xdisplay))
+    return;
+
+  infos = XineramaQueryScreens (screen->display->xdisplay, &n_infos);
+  if (n_infos <= 0 || infos == NULL)
     {
-      /* In case we've filtered previous monitors */
-      screen->monitor_infos[i].number = i;
+      meta_XFree (infos);
+      return;
+    }
 
-      for (j = 0; j < i; j++)
+  for (i = 0; i < screen->n_monitor_infos; ++i)
+    {
+      for (j = 0; j < n_infos; ++j)
         {
-          if (meta_rectangle_equal (&screen->monitor_infos[i].rect,
-                                    &screen->monitor_infos[j].rect))
-            {
-              memmove (&screen->monitor_infos[i],
-                       &screen->monitor_infos[i + 1],
-                       (screen->n_monitor_infos - i - 1) * sizeof (MetaMonitorInfo));
-              screen->n_monitor_infos--;
-              i--;
-
-              continue;
-            }
+          if (screen->monitor_infos[i].rect.x == infos[j].x_org &&
+	      screen->monitor_infos[i].rect.y == infos[j].y_org &&
+	      screen->monitor_infos[i].rect.width == infos[j].width &&
+	      screen->monitor_infos[i].rect.height == infos[j].height)
+            screen->monitor_infos[i].xinerama_index = j;
         }
     }
+
+  meta_XFree (infos);
 }
 
-#ifdef HAVE_RANDR
-static MetaMonitorInfo *
-find_monitor_with_rect (MetaScreen *screen, int x, int y, int w, int h)
+int
+meta_screen_monitor_index_to_xinerama_index (MetaScreen *screen,
+                                             int         index)
 {
-  MetaMonitorInfo *info;
-  int i;
+  meta_screen_ensure_xinerama_indices (screen);
 
-  for (i = 0; i < screen->n_monitor_infos; i++)
-    {
-      info = &screen->monitor_infos[i];
-      if (x == info->rect.x &&
-          y == info->rect.y &&
-          w == info->rect.width &&
-          h == info->rect.height)
-        return info;
-    }
-  return NULL;
+  return screen->monitor_infos[index].xinerama_index;
 }
 
-/* In the case of multiple outputs of a single crtc (mirroring), we consider one of the
- * outputs the "main". This is the one we consider "owning" the windows, so if
- * the mirroring is changed to a dual monitor setup then the windows are moved to the
- * crtc that now has that main output. If one of the outputs is the primary that is
- * always the main, otherwise we just use the first.
- */
-static XID
-find_main_output_for_crtc (MetaScreen *screen, XRRScreenResources *resources, XRRCrtcInfo *crtc)
+int
+meta_screen_xinerama_index_to_monitor_index (MetaScreen *screen,
+                                             int         index)
 {
-  XRROutputInfo *output;
-  RROutput primary_output;
   int i;
-  XID res;
 
-  primary_output = XRRGetOutputPrimary (screen->display->xdisplay, screen->xroot);
+  meta_screen_ensure_xinerama_indices (screen);
 
-  res = None;
-  for (i = 0; i < crtc->noutput; i++)
-    {
-      output = XRRGetOutputInfo (screen->display->xdisplay, resources, crtc->outputs[i]);
-      if (output->connection != RR_Disconnected &&
-          (res == None || crtc->outputs[i] == primary_output))
-        res = crtc->outputs[i];
-      XRRFreeOutputInfo (output);
-    }
+  for (i = 0; i < screen->n_monitor_infos; i++)
+    if (screen->monitor_infos[i].xinerama_index == index)
+      return i;
 
-  return res;
+  return -1;
 }
 
-#endif
-
 static void
 reload_monitor_infos (MetaScreen *screen)
 {
-  MetaDisplay *display;
-
-  {
-    GList *tmp;
-
-    tmp = screen->workspaces;
-    while (tmp != NULL)
-      {
-        MetaWorkspace *space = tmp->data;
-
-        meta_workspace_invalidate_work_area (space);
-        
-        tmp = tmp->next;
-      }
-  }
-
-  display = screen->display;
-
-  /* Any previous screen->monitor_infos is freed by the caller */
-
-  screen->monitor_infos = NULL;
-  screen->n_monitor_infos = 0;
-  screen->last_monitor_index = 0;
-
-  /* Xinerama doesn't have a concept of primary monitor, however XRandR
-   * does. However, the XRandR xinerama compat code always sorts the
-   * primary output first, so we rely on that here. We could use the
-   * native XRandR calls instead of xinerama, but that would be
-   * slightly problematic for _NET_WM_FULLSCREEN_MONITORS support, as
-   * that is defined in terms of xinerama monitor indexes.
-   * So, since we don't need anything in xrandr except the primary
-   * we can keep using xinerama and use the first monitor as the
-   * primary.
-   */
-  screen->primary_monitor_index = 0;
-
-  screen->display->monitor_cache_invalidated = TRUE;
-
-  if (g_getenv ("MUTTER_DEBUG_XINERAMA"))
-    {
-      meta_topic (META_DEBUG_XINERAMA,
-                  "Pretending a single monitor has two Xinerama screens\n");
-
-      screen->monitor_infos = g_new0 (MetaMonitorInfo, 2);
-      screen->n_monitor_infos = 2;
-
-      screen->monitor_infos[0].number = 0;
-      screen->monitor_infos[0].rect = screen->rect;
-      screen->monitor_infos[0].rect.width = screen->rect.width / 2;
-      screen->monitor_infos[0].in_fullscreen = -1;
-
-      screen->monitor_infos[1].number = 1;
-      screen->monitor_infos[1].rect = screen->rect;
-      screen->monitor_infos[1].rect.x = screen->rect.width / 2;
-      screen->monitor_infos[1].rect.width = screen->rect.width / 2;
-      screen->monitor_infos[0].in_fullscreen = -1;
-    }
+  GList *tmp;
+  MetaMonitorManager *manager;
 
-  if (screen->n_monitor_infos == 0 &&
-      XineramaIsActive (display->xdisplay))
+  tmp = screen->workspaces;
+  while (tmp != NULL)
     {
-      XineramaScreenInfo *infos;
-      int n_infos;
-      int i;
-      
-      n_infos = 0;
-      infos = XineramaQueryScreens (display->xdisplay, &n_infos);
+      MetaWorkspace *space = tmp->data;
 
-      meta_topic (META_DEBUG_XINERAMA,
-                  "Found %d Xinerama screens on display %s\n",
-                  n_infos, display->name);
-
-      if (n_infos > 0)
-        {
-          screen->monitor_infos = g_new0 (MetaMonitorInfo, n_infos);
-          screen->n_monitor_infos = n_infos;
-          
-          i = 0;
-          while (i < n_infos)
-            {
-              screen->monitor_infos[i].number = infos[i].screen_number;
-              screen->monitor_infos[i].rect.x = infos[i].x_org;
-              screen->monitor_infos[i].rect.y = infos[i].y_org;
-              screen->monitor_infos[i].rect.width = infos[i].width;
-              screen->monitor_infos[i].rect.height = infos[i].height;
-              screen->monitor_infos[i].in_fullscreen = -1;
-
-              meta_topic (META_DEBUG_XINERAMA,
-                          "Monitor %d is %d,%d %d x %d\n",
-                          screen->monitor_infos[i].number,
-                          screen->monitor_infos[i].rect.x,
-                          screen->monitor_infos[i].rect.y,
-                          screen->monitor_infos[i].rect.width,
-                          screen->monitor_infos[i].rect.height);
-              
-              ++i;
-            }
-        }
+      meta_workspace_invalidate_work_area (space);
       
-      meta_XFree (infos);
-
-#ifdef HAVE_RANDR
-      {
-        XRRScreenResources *resources;
-
-        resources = XRRGetScreenResourcesCurrent (display->xdisplay, screen->xroot);
-        if (resources)
-          {
-            for (i = 0; i < resources->ncrtc; i++)
-              {
-                XRRCrtcInfo *crtc;
-                MetaMonitorInfo *info;
-
-                crtc = XRRGetCrtcInfo (display->xdisplay, resources, resources->crtcs[i]);
-                info = find_monitor_with_rect (screen, crtc->x, crtc->y, (int)crtc->width, (int)crtc->height);
-                if (info)
-                  info->output = find_main_output_for_crtc (screen, resources, crtc);
-
-                XRRFreeCrtcInfo (crtc);
-              }
-            XRRFreeScreenResources (resources);
-          }
-      }
-#endif
-    }
-  else if (screen->n_monitor_infos > 0)
-    {
-      meta_topic (META_DEBUG_XINERAMA,
-                  "No Xinerama extension or Xinerama inactive on display %s\n",
-                  display->name);
+      tmp = tmp->next;
     }
 
-  /* If no Xinerama, fill in the single screen info so
-   * we can use the field unconditionally
-   */
-  if (screen->n_monitor_infos == 0)
-    {
-      meta_topic (META_DEBUG_XINERAMA,
-                  "No Xinerama screens, using default screen info\n");
-          
-      screen->monitor_infos = g_new0 (MetaMonitorInfo, 1);
-      screen->n_monitor_infos = 1;
-          
-      screen->monitor_infos[0].number = 0;
-      screen->monitor_infos[0].rect = screen->rect;
-      screen->monitor_infos[0].in_fullscreen = -1;
-    }
+  /* Any previous screen->monitor_infos or screen->outputs is freed by the caller */
 
-  filter_mirrored_monitors (screen);
+  screen->last_monitor_index = 0;
+  screen->has_xinerama_indices = FALSE;
+  screen->display->monitor_cache_invalidated = TRUE;
 
-  screen->monitor_infos[screen->primary_monitor_index].is_primary = TRUE;
+  manager = meta_monitor_manager_get ();
 
-  g_assert (screen->n_monitor_infos > 0);
-  g_assert (screen->monitor_infos != NULL);
+  screen->monitor_infos = meta_monitor_manager_get_monitor_infos (manager,
+                                                                  &screen->n_monitor_infos);
+  screen->primary_monitor_index = meta_monitor_manager_get_primary_index (manager);
 }
 
 /* The guard window allows us to leave minimized windows mapped so
@@ -852,11 +694,17 @@ meta_screen_new (MetaDisplay *display,
   screen->compositor_data = NULL;
   screen->guard_window = None;
 
-  screen->monitor_infos = NULL;
-  screen->n_monitor_infos = 0;
-  screen->last_monitor_index = 0;  
-  
-  reload_monitor_infos (screen);
+  {
+    MetaMonitorManager *manager;
+
+    meta_monitor_manager_initialize (screen->display->xdisplay);
+
+    reload_monitor_infos (screen);
+
+    manager = meta_monitor_manager_get ();
+    g_signal_connect (manager, "monitors-changed",
+                      G_CALLBACK (on_monitors_changed), screen);
+  }
   
   meta_screen_set_cursor (screen, META_CURSOR_DEFAULT);
 
@@ -941,7 +789,7 @@ meta_screen_new (MetaDisplay *display,
 
   meta_verbose ("Added screen %d ('%s') root 0x%lx\n",
                 screen->number, screen->screen_name, screen->xroot);
-  
+
   return screen;
 }
 
@@ -3002,14 +2850,17 @@ meta_screen_resize (MetaScreen *screen,
                     int         width,
                     int         height)
 {
-  GSList *windows, *tmp;
-  MetaMonitorInfo *old_monitor_infos;
-
   screen->rect.width = width;
   screen->rect.height = height;
 
-  /* Save the old monitor infos, so they stay valid during the update */
-  old_monitor_infos = screen->monitor_infos;
+  meta_monitor_manager_invalidate (meta_monitor_manager_get ());
+}
+
+static void
+on_monitors_changed (MetaMonitorManager *manager,
+                     MetaScreen         *screen)
+{
+  GSList *tmp, *windows;
 
   reload_monitor_infos (screen);
   set_desktop_geometry_hint (screen);
@@ -3021,8 +2872,8 @@ meta_screen_resize (MetaScreen *screen,
 
       changes.x = 0;
       changes.y = 0;
-      changes.width = width;
-      changes.height = height;
+      changes.width = screen->rect.width;
+      changes.height = screen->rect.height;
 
       XConfigureWindow(screen->display->xdisplay,
                        screen->guard_window,
@@ -3032,7 +2883,8 @@ meta_screen_resize (MetaScreen *screen,
 
   if (screen->display->compositor)
     meta_compositor_sync_screen_size (screen->display->compositor,
-				      screen, width, height);
+				      screen,
+                                      screen->rect.width, screen->rect.height);
 
   /* Queue a resize on all the windows */
   meta_screen_foreach_window (screen, meta_screen_resize_func, 0);
@@ -3048,7 +2900,6 @@ meta_screen_resize (MetaScreen *screen,
         meta_window_update_for_monitors_changed (window);
     }
 
-  g_free (old_monitor_infos);
   g_slist_free (windows);
 
   meta_screen_queue_check_fullscreen (screen);
diff --git a/src/core/window-private.h b/src/core/window-private.h
index 2fb101670..e7255beab 100644
--- a/src/core/window-private.h
+++ b/src/core/window-private.h
@@ -165,7 +165,7 @@ struct _MetaWindow
    * been overridden (via a client message), the window will cover the union of
    * these monitors.  If not, this is the single monitor which the window's
    * origin is on. */
-  long fullscreen_monitors[4];
+  gint fullscreen_monitors[4];
   
   /* Whether we're trying to constrain the window to be fully onscreen */
   guint require_fully_onscreen : 1;
diff --git a/src/core/window.c b/src/core/window.c
index 33723535d..b5a4984bb 100644
--- a/src/core/window.c
+++ b/src/core/window.c
@@ -2108,10 +2108,14 @@ set_net_wm_state (MetaWindow *window)
 
   if (window->fullscreen)
     {
-      data[0] = window->fullscreen_monitors[0];
-      data[1] = window->fullscreen_monitors[1];
-      data[2] = window->fullscreen_monitors[2];
-      data[3] = window->fullscreen_monitors[3];
+      data[0] = meta_screen_monitor_index_to_xinerama_index (window->screen,
+                                                             window->fullscreen_monitors[0]);
+      data[1] = meta_screen_monitor_index_to_xinerama_index (window->screen,
+                                                             window->fullscreen_monitors[1]);
+      data[2] = meta_screen_monitor_index_to_xinerama_index (window->screen,
+                                                             window->fullscreen_monitors[2]);
+      data[3] = meta_screen_monitor_index_to_xinerama_index (window->screen,
+                                                             window->fullscreen_monitors[3]);
 
       meta_verbose ("Setting _NET_WM_FULLSCREEN_MONITORS\n");
       meta_error_trap_push (window->display);
@@ -4785,7 +4789,8 @@ meta_window_update_for_monitors_changed (MetaWindow *window)
     {
       MetaMonitorInfo *info = &window->screen->monitor_infos[i];
 
-      if (info->output == old->output)
+      if (info->output_id != 0 &&
+          info->output_id == old->output_id)
         {
           new = info;
           break;
@@ -7130,10 +7135,14 @@ meta_window_client_message (MetaWindow *window,
       meta_verbose ("_NET_WM_FULLSCREEN_MONITORS request for window '%s'\n",
                     window->desc);
 
-      top = event->xclient.data.l[0];
-      bottom = event->xclient.data.l[1];
-      left = event->xclient.data.l[2];
-      right = event->xclient.data.l[3];
+      top = meta_screen_xinerama_index_to_monitor_index (window->screen,
+                                                         event->xclient.data.l[0]);
+      bottom = meta_screen_xinerama_index_to_monitor_index (window->screen,
+                                                            event->xclient.data.l[1]);
+      left = meta_screen_xinerama_index_to_monitor_index (window->screen,
+                                                          event->xclient.data.l[2]);
+      right = meta_screen_xinerama_index_to_monitor_index (window->screen,
+                                                           event->xclient.data.l[3]);
       /* source_indication = event->xclient.data.l[4]; */
 
       meta_window_update_fullscreen_monitors (window, top, bottom, left, right);