[gtk+] window: Allow _gtk_window_set_allocation to return a modified allocation

[Matthias Clasen <matthiasc src gnome org>]

commit 55a98da4d44117a34cc733c27120e114f7bd7260
Author: Rob Bradford <rob linux intel com>
Date:   Tue Feb 26 19:33:04 2013 +0000

    window: Allow _gtk_window_set_allocation to return a modified allocation
    
    Update the documentation and users of this function to handle
    the future case that that we have some internal decorations to the window and
    useable allocation is thus smaller.
    
    By having a separate out parameter there is no need to have an in/out function
    and allows for greater robustness.
    
    The current implementation simply returns the allocation provided.

 gtk/gtkapplicationwindow.c |   11 +++++++----
 gtk/gtkwindow.c            |   29 +++++++++++++++++++++--------
 gtk/gtkwindowprivate.h     |    5 +++--
 3 files changed, 31 insertions(+), 14 deletions(-)
---
diff --git a/gtk/gtkapplicationwindow.c b/gtk/gtkapplicationwindow.c
index 271054b..541baf6 100644
--- a/gtk/gtkapplicationwindow.c
+++ b/gtk/gtkapplicationwindow.c
@@ -703,13 +703,17 @@ gtk_application_window_real_size_allocate (GtkWidget     *widget,
 
   if (window->priv->menubar != NULL)
     {
-      GtkAllocation menubar_allocation = *allocation;
+      GtkAllocation menubar_allocation;
+      GtkAllocation child_allocation;
       gint menubar_height;
       GtkWidget *child;
 
-      _gtk_window_set_allocation (GTK_WINDOW (widget), allocation);
+      _gtk_window_set_allocation (GTK_WINDOW (widget), allocation, &child_allocation);
+      menubar_allocation = child_allocation;
 
-      gtk_widget_get_preferred_height_for_width (window->priv->menubar, allocation->width, &menubar_height, 
NULL);
+      gtk_widget_get_preferred_height_for_width (window->priv->menubar,
+                                                 menubar_allocation.width,
+                                                 &menubar_height, NULL);
 
       menubar_allocation.height = menubar_height;
       gtk_widget_size_allocate (window->priv->menubar, &menubar_allocation);
@@ -717,7 +721,6 @@ gtk_application_window_real_size_allocate (GtkWidget     *widget,
       child = gtk_bin_get_child (GTK_BIN (window));
       if (child != NULL && gtk_widget_get_visible (child))
         {
-          GtkAllocation child_allocation = *allocation;
           gint border_width;
 
           border_width = gtk_container_get_border_width (GTK_CONTAINER (window));
diff --git a/gtk/gtkwindow.c b/gtk/gtkwindow.c
index 99bab05..c0dc07e 100644
--- a/gtk/gtkwindow.c
+++ b/gtk/gtkwindow.c
@@ -5504,7 +5504,9 @@ set_grip_position (GtkWindow *window)
 
 /* _gtk_window_set_allocation:
  * @window: a #GtkWindow
- * @allocation: the new allocation
+ * @allocation: the original allocation for the window
+ * @allocation_out: @allocation taking decorations into
+ * consideration
  *
  * This function is like gtk_widget_set_allocation()
  * but does the necessary extra work to update
@@ -5513,13 +5515,22 @@ set_grip_position (GtkWindow *window)
  * Call this instead of gtk_widget_set_allocation()
  * when overriding ::size_allocate in a GtkWindow
  * subclass without chaining up.
+ *
+ * The @allocation parameter will be adjusted to
+ * reflect any internal decorations that the window
+ * may have. That revised allocation will then be
+ * returned in the @allocation_out parameter.
  */
 void
-_gtk_window_set_allocation (GtkWindow     *window,
-                            GtkAllocation *allocation)
+_gtk_window_set_allocation (GtkWindow           *window,
+                            const GtkAllocation *allocation,
+                            GtkAllocation       *allocation_out)
 {
   GtkWidget *widget = (GtkWidget *)window;
 
+  g_assert (allocation != NULL);
+  g_assert (allocation_out != NULL);
+
   gtk_widget_set_allocation (widget, allocation);
 
   if (gtk_widget_get_realized (widget))
@@ -5539,6 +5550,8 @@ _gtk_window_set_allocation (GtkWindow     *window,
           set_grip_position (window);
         }
     }
+
+  *allocation_out = *allocation;
 }
 
 static void
@@ -5550,16 +5563,16 @@ gtk_window_size_allocate (GtkWidget     *widget,
   GtkWidget *child;
   guint border_width;
 
-  _gtk_window_set_allocation (window, allocation);
+  _gtk_window_set_allocation (window, allocation, &child_allocation);
 
   child = gtk_bin_get_child (&(window->bin));
   if (child && gtk_widget_get_visible (child))
     {
       border_width = gtk_container_get_border_width (GTK_CONTAINER (window));
-      child_allocation.x = border_width;
-      child_allocation.y = border_width;
-      child_allocation.width = MAX (1, allocation->width - border_width * 2);
-      child_allocation.height = MAX (1, allocation->height - border_width * 2);
+      child_allocation.x += border_width;
+      child_allocation.y += border_width;
+      child_allocation.width = MAX (1, child_allocation.width - border_width * 2);
+      child_allocation.height = MAX (1, child_allocation.height - border_width * 2);
 
       gtk_widget_size_allocate (child, &child_allocation);
     }
diff --git a/gtk/gtkwindowprivate.h b/gtk/gtkwindowprivate.h
index 22f8d57..8891ca4 100644
--- a/gtk/gtkwindowprivate.h
+++ b/gtk/gtkwindowprivate.h
@@ -66,8 +66,9 @@ void            _gtk_window_get_wmclass            (GtkWindow  *window,
                                                     gchar     **wmclass_name,
                                                     gchar     **wmclass_class);
 
-void            _gtk_window_set_allocation         (GtkWindow     *window,
-                                                    GtkAllocation *allocation);
+void            _gtk_window_set_allocation         (GtkWindow           *window,
+                                                    const GtkAllocation *allocation,
+                                                    GtkAllocation       *allocation_out);
 
 typedef void (*GtkWindowKeysForeachFunc) (GtkWindow      *window,
                                           guint           keyval,