[gtk+] viewport: Rewrite adjustment modification code for sealing

[Benjamin Otte <otte src gnome org>]

commit 2b4bb071a3cc4bb8daa501b15223139e51150e0e
Author: Benjamin Otte <otte redhat com>
Date:   Wed Jan 5 21:53:04 2011 +0100

    viewport: Rewrite adjustment modification code for sealing

 gtk/gtkviewport.c |  115 ++++++++++++++++++++---------------------------------
 1 files changed, 43 insertions(+), 72 deletions(-)
---
diff --git a/gtk/gtkviewport.c b/gtk/gtkviewport.c
index dfa8f15..34c6a3e 100644
--- a/gtk/gtkviewport.c
+++ b/gtk/gtkviewport.c
@@ -341,23 +341,6 @@ viewport_get_view_allocation (GtkViewport   *viewport,
   view_allocation->height = MAX (1, allocation.height - view_allocation->y * 2 - border_width * 2);
 }
 
-static void
-viewport_reclamp_adjustment (GtkAdjustment *adjustment,
-			     gboolean      *value_changed)
-{
-  gdouble value = adjustment->value;
-
-  value = CLAMP (value, 0, adjustment->upper - adjustment->page_size);
-  if (value != adjustment->value)
-    {
-      adjustment->value = value;
-      if (value_changed)
-	*value_changed = TRUE;
-    }
-  else if (value_changed)
-    *value_changed = FALSE;
-}
-
 /**
  * gtk_viewport_get_hadjustment:
  * @viewport: a #GtkViewport.
@@ -409,28 +392,16 @@ gtk_viewport_get_vadjustment (GtkViewport *viewport)
 }
 
 static void
-viewport_set_hadjustment_values (GtkViewport *viewport,
-				 gboolean    *value_changed)
+viewport_set_hadjustment_values (GtkViewport *viewport)
 {
   GtkBin *bin = GTK_BIN (viewport);
   GtkAllocation view_allocation;
   GtkAdjustment *hadjustment = gtk_viewport_get_hadjustment (viewport);
   GtkWidget *child;
-  gdouble old_page_size;
-  gdouble old_upper;
-  gdouble old_value;
+  gdouble upper, value;
   
   viewport_get_view_allocation (viewport, &view_allocation);  
 
-  old_page_size = hadjustment->page_size;
-  old_upper = hadjustment->upper;
-  old_value = hadjustment->value;
-  hadjustment->page_size = view_allocation.width;
-  hadjustment->step_increment = view_allocation.width * 0.1;
-  hadjustment->page_increment = view_allocation.width * 0.9;
-  
-  hadjustment->lower = 0;
-
   child = gtk_bin_get_child (bin);
   if (child && gtk_widget_get_visible (child))
     {
@@ -448,41 +419,43 @@ viewport_set_hadjustment_values (GtkViewport *viewport,
                                                  &natural_width);
 
       if (viewport->priv->hscroll_policy == GTK_SCROLL_MINIMUM)
-	hadjustment->upper = MAX (minimum_width, view_allocation.width);
+	upper = MAX (minimum_width, view_allocation.width);
       else
-	hadjustment->upper = MAX (natural_width, view_allocation.width);
+	upper = MAX (natural_width, view_allocation.width);
     }
   else
-    hadjustment->upper = view_allocation.width;
+    upper = view_allocation.width;
 
-  if (gtk_widget_get_direction (GTK_WIDGET (viewport)) == GTK_TEXT_DIR_RTL) 
+  value = gtk_adjustment_get_value (hadjustment);
+  /* We clamp to the left in RTL mode */
+  if (gtk_widget_get_direction (GTK_WIDGET (viewport)) == GTK_TEXT_DIR_RTL)
     {
-      gdouble dist = old_upper - (old_value + old_page_size);
-      hadjustment->value = hadjustment->upper - dist - hadjustment->page_size;
-      viewport_reclamp_adjustment (hadjustment, value_changed);
-      *value_changed = (old_value != hadjustment->value);
+      gdouble dist = gtk_adjustment_get_upper (hadjustment)
+                     - value
+                     - gtk_adjustment_get_page_size (hadjustment);
+      value = upper - dist - view_allocation.width;
     }
-  else
-    viewport_reclamp_adjustment (hadjustment, value_changed);
+
+  gtk_adjustment_configure (hadjustment,
+                            value,
+                            0,
+                            upper,
+                            view_allocation.width * 0.1,
+                            view_allocation.width * 0.9,
+                            view_allocation.width);
 }
 
 static void
-viewport_set_vadjustment_values (GtkViewport *viewport,
-				 gboolean    *value_changed)
+viewport_set_vadjustment_values (GtkViewport *viewport)
 {
   GtkBin *bin = GTK_BIN (viewport);
   GtkAllocation view_allocation;
   GtkAdjustment *vadjustment = gtk_viewport_get_vadjustment (viewport);
   GtkWidget *child;
+  gdouble upper;
 
   viewport_get_view_allocation (viewport, &view_allocation);  
 
-  vadjustment->page_size = view_allocation.height;
-  vadjustment->step_increment = view_allocation.height * 0.1;
-  vadjustment->page_increment = view_allocation.height * 0.9;
-  
-  vadjustment->lower = 0;
-
   child = gtk_bin_get_child (bin);
   if (child && gtk_widget_get_visible (child))
     {
@@ -500,14 +473,20 @@ viewport_set_vadjustment_values (GtkViewport *viewport,
                                                  &natural_height);
 
       if (viewport->priv->vscroll_policy == GTK_SCROLL_MINIMUM)
-	vadjustment->upper = MAX (minimum_height, view_allocation.height);
+	upper = MAX (minimum_height, view_allocation.height);
       else
-	vadjustment->upper = MAX (natural_height, view_allocation.height);
+	upper = MAX (natural_height, view_allocation.height);
     }
   else
-    vadjustment->upper = view_allocation.height;
-
-  viewport_reclamp_adjustment (vadjustment, value_changed);
+    upper = view_allocation.height;
+
+  gtk_adjustment_configure (vadjustment,
+                            gtk_adjustment_get_value (vadjustment),
+                            0,
+                            upper,
+                            view_allocation.height * 0.1,
+                            view_allocation.height * 0.9,
+                            view_allocation.height);
 }
 
 static void
@@ -516,7 +495,6 @@ viewport_set_adjustment (GtkViewport    *viewport,
 			 GtkAdjustment  *adjustment)
 {
   GtkAdjustment **adjustmentp = ADJUSTMENT_POINTER (viewport, orientation);
-  gboolean value_changed;
 
   if (adjustment && adjustment == *adjustmentp)
     return;
@@ -528,20 +506,15 @@ viewport_set_adjustment (GtkViewport    *viewport,
   g_object_ref_sink (adjustment);
 
   if (orientation == GTK_ORIENTATION_HORIZONTAL)
-    viewport_set_hadjustment_values (viewport, &value_changed);
+    viewport_set_hadjustment_values (viewport);
   else
-    viewport_set_vadjustment_values (viewport, &value_changed);
+    viewport_set_vadjustment_values (viewport);
 
   g_signal_connect (adjustment, "value-changed",
 		    G_CALLBACK (gtk_viewport_adjustment_value_changed),
 		    viewport);
 
-  gtk_adjustment_changed (adjustment);
-  
-  if (value_changed)
-    gtk_adjustment_value_changed (adjustment);
-  else
-    gtk_viewport_adjustment_value_changed (adjustment, viewport);
+  gtk_viewport_adjustment_value_changed (adjustment, viewport);
 }
 
 /**
@@ -847,7 +820,6 @@ gtk_viewport_size_allocate (GtkWidget     *widget,
   GtkViewportPrivate *priv = viewport->priv;
   GtkBin *bin = GTK_BIN (widget);
   guint border_width;
-  gboolean hadjustment_value_changed, vadjustment_value_changed;
   GtkAdjustment *hadjustment = gtk_viewport_get_hadjustment (viewport);
   GtkAdjustment *vadjustment = gtk_viewport_get_vadjustment (viewport);
   GtkAllocation child_allocation;
@@ -867,8 +839,11 @@ gtk_viewport_size_allocate (GtkWidget     *widget,
 
   gtk_widget_set_allocation (widget, allocation);
 
-  viewport_set_hadjustment_values (viewport, &hadjustment_value_changed);
-  viewport_set_vadjustment_values (viewport, &vadjustment_value_changed);
+  g_object_freeze_notify (G_OBJECT (hadjustment));
+  g_object_freeze_notify (G_OBJECT (vadjustment));
+
+  viewport_set_hadjustment_values (viewport);
+  viewport_set_vadjustment_values (viewport);
   
   child_allocation.x = 0;
   child_allocation.y = 0;
@@ -901,12 +876,8 @@ gtk_viewport_size_allocate (GtkWidget     *widget,
   if (child && gtk_widget_get_visible (child))
     gtk_widget_size_allocate (child, &child_allocation);
 
-  gtk_adjustment_changed (hadjustment);
-  gtk_adjustment_changed (vadjustment);
-  if (hadjustment_value_changed)
-    gtk_adjustment_value_changed (hadjustment);
-  if (vadjustment_value_changed)
-    gtk_adjustment_value_changed (vadjustment);
+  g_object_thaw_notify (G_OBJECT (hadjustment));
+  g_object_thaw_notify (G_OBJECT (vadjustment));
 }
 
 static void