check compositor status

5 files changed, 34 insertions, 30 deletions

diff --git a/src/core/screen-private.h b/src/core/screen-private.h
index 0103c6ad..ee014ff2 100644
--- a/src/core/screen-private.h
+++ b/src/core/screen-private.h
@@ -115,6 +115,7 @@ struct _MetaScreen
 #endif
 
 #ifdef HAVE_COMPOSITE_EXTENSIONS
+  Atom wm_cm_atom;
   Window wm_cm_selection_window;
   guint32 wm_cm_timestamp;
 #endif
diff --git a/src/core/screen.c b/src/core/screen.c
index 6c555126..66461d4a 100644
--- a/src/core/screen.c
+++ b/src/core/screen.c
@@ -485,6 +485,8 @@ meta_screen_new (MetaDisplay *display,
   screen->wm_sn_timestamp = manager_timestamp;
 
 #ifdef HAVE_COMPOSITE_EXTENSIONS
+  g_snprintf (buf, sizeof(buf), "_NET_WM_CM_S%d", screen->number);
+  screen->wm_cm_atom = XInternAtom (screen->display->xdisplay, buf, FALSE);
   screen->wm_cm_selection_window = meta_create_offscreen_window (xdisplay,
                                                                  xroot,
                                                                  NoEventMask);
@@ -1508,7 +1510,7 @@ meta_screen_tile_preview_update_timeout (gpointer data)
       MetaRectangle tile_rect;
 
       meta_window_get_current_tile_area (window, &tile_rect);
-      meta_tile_preview_show (screen->tile_preview, &tile_rect);
+      meta_tile_preview_show (screen->tile_preview, &tile_rect, screen);
     }
   else
     meta_tile_preview_hide (screen->tile_preview);
@@ -2894,28 +2896,25 @@ meta_screen_set_compositor_data (MetaScreen *screen,
 void
 meta_screen_set_cm_selection (MetaScreen *screen)
 {
-  char selection[32];
-  Atom a;
-
   screen->wm_cm_timestamp = meta_display_get_current_time_roundtrip (
                                                                screen->display);
 
-  g_snprintf (selection, sizeof(selection), "_NET_WM_CM_S%d", screen->number);
-  meta_verbose ("Setting selection: %s\n", selection);
-  a = XInternAtom (screen->display->xdisplay, selection, FALSE);
-  XSetSelectionOwner (screen->display->xdisplay, a,
+  meta_verbose ("Setting selection for screen: %d\n", screen->number);
+  XSetSelectionOwner (screen->display->xdisplay, screen->wm_cm_atom,
                       screen->wm_cm_selection_window, screen->wm_cm_timestamp);
 }
 
 void
 meta_screen_unset_cm_selection (MetaScreen *screen)
 {
-  char selection[32];
-  Atom a;
-
-  g_snprintf (selection, sizeof(selection), "_NET_WM_CM_S%d", screen->number);
-  a = XInternAtom (screen->display->xdisplay, selection, FALSE);
-  XSetSelectionOwner (screen->display->xdisplay, a,
+  XSetSelectionOwner (screen->display->xdisplay, screen->wm_cm_atom,
                       None, screen->wm_cm_timestamp);
 }
+
+gboolean
+meta_screen_is_cm_selected (MetaScreen *screen)
+{
+  Window owner = XGetSelectionOwner (screen->display->xdisplay, screen->wm_cm_atom);
+  return owner != None;
+}
 #endif /* HAVE_COMPOSITE_EXTENSIONS */
diff --git a/src/include/screen.h b/src/include/screen.h
index 759c1fd2..34f4d008 100644
--- a/src/include/screen.h
+++ b/src/include/screen.h
@@ -43,6 +43,7 @@ MetaScreen *meta_screen_for_x_screen (Screen *xscreen);
 #ifdef HAVE_COMPOSITE_EXTENSIONS
 void meta_screen_set_cm_selection (MetaScreen *screen);
 void meta_screen_unset_cm_selection (MetaScreen *screen);
+gboolean meta_screen_is_cm_selected (MetaScreen *screen);
 #endif
 
 #endif
diff --git a/src/include/tile-preview.h b/src/include/tile-preview.h
index 88af4f49..70ceec9e 100644
--- a/src/include/tile-preview.h
+++ b/src/include/tile-preview.h
@@ -24,13 +24,15 @@
 #define META_TILE_PREVIEW_H
 
 #include "boxes.h"
+#include "types.h"
 
 typedef struct _MetaTilePreview MetaTilePreview;
 
 MetaTilePreview   *meta_tile_preview_new    (int                screen_number);
 void               meta_tile_preview_free   (MetaTilePreview   *preview);
 void               meta_tile_preview_show   (MetaTilePreview   *preview,
-                                             MetaRectangle     *rect);
+                                             MetaRectangle     *rect,
+                                             MetaScreen        *screen);
 void               meta_tile_preview_hide   (MetaTilePreview   *preview);
 
 #endif /* META_TILE_PREVIEW_H */
diff --git a/src/ui/tile-preview.c b/src/ui/tile-preview.c
index 75eba055..ee58600d 100644
--- a/src/ui/tile-preview.c
+++ b/src/ui/tile-preview.c
@@ -28,6 +28,8 @@
 
 #include "tile-preview.h"
 #include "core.h"
+#include "types.h"
+#include "core/screen-private.h"
 
 #define OUTLINE_WIDTH 5  /* frame width in non-composite case */
 
@@ -206,23 +208,14 @@ meta_tile_preview_new (int      screen_number)
   preview->tile_rect.width = preview->tile_rect.height = 0;
 
 #if GTK_CHECK_VERSION (3, 0, 0)
-  preview->has_alpha = gdk_screen_is_composited (screen) && (gdk_screen_get_rgba_visual (screen) != NULL);
+  gtk_widget_set_visual (preview->preview_window,
+                         gdk_screen_get_rgba_visual (screen));
 #else
-  preview->has_alpha = rgba_colormap && gdk_screen_is_composited (screen);
+  gtk_widget_set_colormap (preview->preview_window, rgba_colormap);
 #endif
 
-  if (preview->has_alpha)
-    {
-#if GTK_CHECK_VERSION (3, 0, 0)
-      gtk_widget_set_visual (preview->preview_window,
-                             gdk_screen_get_rgba_visual (screen));
-#else
-      gtk_widget_set_colormap (preview->preview_window, rgba_colormap);
-#endif
-
-      g_signal_connect (preview->preview_window, "style-set",
-                        G_CALLBACK (on_preview_window_style_set), preview);
-    }
+  g_signal_connect (preview->preview_window, "style-set",
+                    G_CALLBACK (on_preview_window_style_set), preview);
 
   gtk_widget_realize (preview->preview_window);
 #if !GTK_CHECK_VERSION (3, 0, 0)
@@ -258,7 +251,8 @@ meta_tile_preview_free (MetaTilePreview *preview)
 
 void
 meta_tile_preview_show (MetaTilePreview *preview,
-                        MetaRectangle   *tile_rect)
+                        MetaRectangle   *tile_rect,
+                        MetaScreen      *screen)
 {
   GdkWindow *window;
   GdkRectangle old_rect;
@@ -291,6 +285,11 @@ meta_tile_preview_show (MetaTilePreview *preview,
   gdk_window_move_resize (window,
                           preview->tile_rect.x, preview->tile_rect.y,
                           preview->tile_rect.width, preview->tile_rect.height);
+#if HAVE_COMPOSITE_EXTENSIONS
+  preview->has_alpha = meta_screen_is_cm_selected (screen);
+#else
+  preview->has_alpha = FALSE;
+#endif
 
   if (!preview->has_alpha)
     {
@@ -337,6 +336,8 @@ meta_tile_preview_show (MetaTilePreview *preview,
       gdk_window_shape_combine_region (window, outer_region, 0, 0);
       gdk_region_destroy (outer_region);
 #endif
+    } else {
+      gdk_window_shape_combine_region (window, NULL, 0, 0);
     }
 }