Add gdk_screen_set_screen()/_get_screen() which (by evil hacks) work for

Wed Oct  2 17:36:42 2002  Owen Taylor  <otaylor@redhat.com>

        * gdk/gdkevents.[ch] gdk/x11/gdkevents-x11.[ch]: Add
        gdk_screen_set_screen()/_get_screen() which (by evil
        hacks) work for for heap allocated events and
        fall back gracefully for stack allocated events.

3 files changed, 103 insertions, 5 deletions

diff --git a/gdk/gdkevents.c b/gdk/gdkevents.c
index cdc3ae5020..ab93e69361 100644
--- a/gdk/gdkevents.c
+++ b/gdk/gdkevents.c
@@ -256,6 +256,7 @@ gdk_event_put (GdkEvent *event)
 }
 
 static GMemChunk *event_chunk = NULL;
+static GHashTable *event_hash = NULL;
 
 GdkEvent*
 _gdk_event_new (void)
@@ -263,17 +264,30 @@ _gdk_event_new (void)
   GdkEventPrivate *new_event;
   
   if (event_chunk == NULL)
-    event_chunk = g_mem_chunk_new ("events",
-				   sizeof (GdkEventPrivate),
-				   4096,
-				   G_ALLOC_AND_FREE);
+    {
+      event_chunk = g_mem_chunk_new ("events",
+				     sizeof (GdkEventPrivate),
+				     4096,
+				     G_ALLOC_AND_FREE);
+      event_hash = g_hash_table_new (g_direct_hash, NULL);
+    }
   
   new_event = g_chunk_new (GdkEventPrivate, event_chunk);
   new_event->flags = 0;
+  new_event->screen = NULL;
+
+  g_hash_table_insert (event_hash, new_event, GUINT_TO_POINTER (1));
   
   return (GdkEvent*) new_event;
 }
 
+static gboolean
+gdk_event_is_allocated (GdkEvent *event)
+{
+  if (event_hash)
+    return g_hash_table_lookup (event_hash, event) != NULL;
+}
+ 
 /**
  * gdk_event_copy:
  * @event: a #GdkEvent
@@ -399,7 +413,8 @@ gdk_event_free (GdkEvent *event)
     default:
       break;
     }
-  
+
+  g_hash_table_remove (event_chunk, event);
   g_mem_chunk_free (event_chunk, event);
 }
 
@@ -739,6 +754,59 @@ gdk_event_get_axis (GdkEvent   *event,
 }
 
 /**
+ * gdk_event_set_screen:
+ * @event: a #GdkEvent
+ * @screen: a #GdkScreen
+ * 
+ * Sets the screen for @event to @screen. The event must
+ * have been allocated by GTK+, for instance, by
+ * gdk_event_copy().
+ **/
+void
+gdk_event_set_screen (GdkEvent  *event,
+		      GdkScreen *screen)
+{
+  GdkEventPrivate *private;
+  
+  g_return_if_fail (gdk_event_is_allocated (event));
+
+  private = (GdkEventPrivate *)event;
+  
+  private->screen = screen;
+}
+
+/**
+ * gdk_event_get_screen:
+ * @event: a #GdkEvent
+ * 
+ * Returns the screen for the event. The screen is
+ * typically the screen for event->any.window, but
+ * for events such as mouse events, it is the screen
+ * where the the pointer was when the event occurs -
+ * that is, the screen which has the root window 
+ * to which event->motion.x_root and
+ * event->motion.y_root are relative.
+ * 
+ * Return value: the screen for the event
+ **/
+GdkScreen *
+gdk_event_get_screen (GdkEvent *event)
+{
+  if (gdk_event_is_allocated (event))
+    {
+      GdkEventPrivate *private = (GdkEventPrivate *)event;
+
+      if (private->screen)
+	return private->screen;
+    }
+
+  if (event->any.window)
+    return gdk_drawable_get_screen (event->any.window);
+
+  return NULL;
+}
+
+/**
  * gdk_set_show_events:
  * @show_events:  %TRUE to output event debugging information.
  * 
diff --git a/gdk/gdkevents.h b/gdk/gdkevents.h
index dbed63cb4d..d9f26167a0 100644
--- a/gdk/gdkevents.h
+++ b/gdk/gdkevents.h
@@ -470,6 +470,10 @@ void	  gdk_event_handler_set 	(GdkEventFunc    func,
 					 gpointer        data,
 					 GDestroyNotify  notify);
 
+void       gdk_event_set_screen (GdkEvent  *event,
+				 GdkScreen *screen);
+GdkScreen *gdk_event_get_screen (GdkEvent  *event);
+
 void	  gdk_set_show_events		(gboolean	 show_events);
 gboolean  gdk_get_show_events		(void);
 
diff --git a/gdk/x11/gdkevents-x11.c b/gdk/x11/gdkevents-x11.c
index 5706a395d8..69a2ef4e67 100644
--- a/gdk/x11/gdkevents-x11.c
+++ b/gdk/x11/gdkevents-x11.c
@@ -499,6 +499,19 @@ generate_focus_event (GdkWindow *window,
   gdk_event_put (&event);
 }
 
+static void
+set_screen_from_root (GdkDisplay *display,
+		      GdkEvent   *event,
+		      Window      xrootwin)
+{
+  GdkScreen *screen;
+
+  screen = _gdk_x11_display_screen_for_xrootwin (display, xrootwin);
+  g_assert (screen);
+
+  gdk_event_set_screen (event, screen);
+}
+
 static gboolean
 gdk_event_translate (GdkDisplay *display,
 		     GdkEvent   *event,
@@ -817,6 +830,9 @@ gdk_event_translate (GdkDisplay *display,
 	  event->scroll.y_root = (gfloat)xevent->xbutton.y_root;
 	  event->scroll.state = (GdkModifierType) xevent->xbutton.state;
 	  event->scroll.device = display->core_pointer;
+
+	  set_screen_from_root (display, event, xevent->xbutton.root);
+	  
           break;
           
         default:
@@ -832,6 +848,8 @@ gdk_event_translate (GdkDisplay *display,
 	  event->button.button = xevent->xbutton.button;
 	  event->button.device = display->core_pointer;
 	  
+	  set_screen_from_root (display, event, xevent->xbutton.root);
+
 	  _gdk_event_button_generate (display, event);
           break;
 	}
@@ -872,6 +890,8 @@ gdk_event_translate (GdkDisplay *display,
       event->button.state = (GdkModifierType) xevent->xbutton.state;
       event->button.button = xevent->xbutton.button;
       event->button.device = display->core_pointer;
+
+      set_screen_from_root (display, event, xevent->xbutton.root);
       
       break;
       
@@ -902,6 +922,8 @@ gdk_event_translate (GdkDisplay *display,
       event->motion.is_hint = xevent->xmotion.is_hint;
       event->motion.device = display->core_pointer;
       
+      set_screen_from_root (display, event, xevent->xmotion.root);
+      
       break;
       
     case EnterNotify:
@@ -954,6 +976,8 @@ gdk_event_translate (GdkDisplay *display,
       event->crossing.x_root = xevent->xcrossing.x_root;
       event->crossing.y_root = xevent->xcrossing.y_root;
       
+      set_screen_from_root (display, event, xevent->xcrossing.root);
+      
       /* Translate the crossing mode into Gdk terms.
        */
       switch (xevent->xcrossing.mode)
@@ -1041,6 +1065,8 @@ gdk_event_translate (GdkDisplay *display,
       event->crossing.x_root = xevent->xcrossing.x_root;
       event->crossing.y_root = xevent->xcrossing.y_root;
       
+      set_screen_from_root (display, event, xevent->xcrossing.root);
+      
       /* Translate the crossing mode into Gdk terms.
        */
       switch (xevent->xcrossing.mode)