gdm r6123 - in trunk: . gui/simple-greeter

[halfline svn gnome org]

Author: halfline
Date: Mon Apr  7 19:14:13 2008
New Revision: 6123
URL: http://svn.gnome.org/viewvc/gdm?rev=6123&view=rev

Log:
2008-04-07 Ray Strode <rstrode redhat com>

	* gui/simple-greeter/gdm-scrollable-widget.c
	(struct GdmScrollableWidgetPrivate),
	(gdm_scrollable_widget_needs_scrollbar),
	(gdm_scrollable_widget_size_request),
	(gdm_scrollable_widget_size_allocate):
	Track whether or not child allocations are out
	of date when determining whether to show scrollbar.
	If they're stale we presume a scrollbar isn't needed.


Modified:
   trunk/ChangeLog
   trunk/gui/simple-greeter/gdm-scrollable-widget.c

Modified: trunk/gui/simple-greeter/gdm-scrollable-widget.c
==============================================================================
--- trunk/gui/simple-greeter/gdm-scrollable-widget.c	(original)
+++ trunk/gui/simple-greeter/gdm-scrollable-widget.c	Mon Apr  7 19:14:13 2008
@@ -54,7 +54,9 @@
         GtkWidget *scrollbar;
 
         GdmScrollableWidgetAnimation *animation;
-        GtkWidget                    *invisible_event_sink;
+        GtkWidget *invisible_event_sink;
+
+        guint      child_adjustments_stale : 1;
 };
 
 struct GdmScrollableWidgetAnimation
@@ -213,6 +215,10 @@
                 return FALSE;
         }
 
+        if (widget->priv->child_adjustments_stale) {
+                return FALSE;
+        }
+
         adjustment = gtk_range_get_adjustment (GTK_RANGE (widget->priv->scrollbar));
 
         return adjustment->upper - adjustment->lower > adjustment->page_size;
@@ -224,6 +230,7 @@
 {
         GdmScrollableWidget *scrollable_widget;
         GtkRequisition       child_requisition;
+        gboolean             child_adjustments_stale;
 
         scrollable_widget = GDM_SCROLLABLE_WIDGET (widget);
 
@@ -233,11 +240,21 @@
         requisition->width += 2 * widget->style->xthickness;
         requisition->height += 2 * widget->style->ythickness;
 
+        child_adjustments_stale = FALSE;
         if (GTK_BIN (widget)->child && GTK_WIDGET_VISIBLE (GTK_BIN (widget)->child)) {
+
+                int old_child_height;
+                gtk_widget_get_child_requisition (GTK_BIN (widget)->child,
+                                                  &child_requisition);
+                old_child_height = child_requisition.height;
+
                 gtk_widget_size_request (GTK_BIN (widget)->child,
                                          &child_requisition);
+
                 requisition->width += child_requisition.width;
                 requisition->height += child_requisition.height;
+
+                child_adjustments_stale = old_child_height != child_requisition.height;
         }
 
         if (gdm_scrollable_widget_needs_scrollbar (scrollable_widget)) {
@@ -254,6 +271,8 @@
         } else {
                 gtk_widget_hide (scrollable_widget->priv->scrollbar);
         }
+
+        scrollable_widget->priv->child_adjustments_stale = child_adjustments_stale;
 }
 
 static void
@@ -303,11 +322,6 @@
         }
 
         if (has_child) {
-                GtkRequisition child_requisition;
-
-                gtk_widget_get_child_requisition (GTK_BIN (widget)->child,
-                                                  &child_requisition);
-
                 child_allocation.width = allocation->width;
                 child_allocation.width -= 2 * GTK_CONTAINER (widget)->border_width;
                 child_allocation.width -= 2 * widget->style->xthickness;
@@ -337,6 +351,7 @@
 
                 gtk_widget_size_allocate (GTK_BIN (widget)->child,
                                           &child_allocation);
+                scrollable_widget->priv->child_adjustments_stale = FALSE;
         }
 }