[gtk+] Revert "gtkbin: Remove the silliest code on earth"

[Tristan Van Berkom <tvb src gnome org>]

commit b164df74506505ac0f4559744ad9b59b5ea57ebf
Author: Tristan Van Berkom <tristanvb openismus com>
Date:   Sat Apr 20 17:52:16 2013 +0900

    Revert "gtkbin: Remove the silliest code on earth"
    
    This reverts commit f4438a1ffc6aaab92fb6b751cd16e95c2abaa0e3.
    
    The calculation of the delta between parent and child widget
    is required in order to automate height-for-width and width-for-height
    requests for various GtkBin widgets.
    
    GtkButton, GtkCheckButton, GtkRadioButton, etc, all have different
    requests for space around the content which can not be satisfied
    with a simple calculation of GtkContainer border-width.

 gtk/gtkbin.c | 78 ++++++++++++++++++++++++++++++++++++++++++++----------------
 1 file changed, 58 insertions(+), 20 deletions(-)
---
diff --git a/gtk/gtkbin.c b/gtk/gtkbin.c
index b64f541..3764938 100644
--- a/gtk/gtkbin.c
+++ b/gtk/gtkbin.c
@@ -189,6 +189,44 @@ gtk_bin_get_effective_border_width (GtkBin *bin)
   return gtk_container_get_border_width (GTK_CONTAINER (bin));
 }
 
+/* GtkBin widgets define the padding and borders independantly so
+ * we cannot provide a generic get_size() for the same reason
+ * we never implemented size_request() here.
+ *
+ * But for cases where the GtkBin class's padding is constant and
+ * does not vary based on allocation (most cases), we can at least 
+ * deduce a common code path for the get_width_for_height()/get_height_for_width()
+ * cases by using the delta of the base size requsts.
+ */
+static void
+get_child_padding_delta (GtkBin *bin,
+                        gint   *delta_h,
+                        gint   *delta_v)
+{
+  GtkBinPrivate *priv = bin->priv;
+  gint hmin, vmin, hnat, vnat, child_hmin, child_vmin;
+
+  /* we can't use gtk_widget_get_preferred_width() wrapper 
+   * because we want our "original" request, not any external
+   * adjustments from set_size_request() or whatever.  we have
+   * to ask for natural also because NULL isn't allowed for the
+   * direct vfuncs
+   */
+  GTK_WIDGET_GET_CLASS (bin)->get_preferred_width (GTK_WIDGET (bin), &hmin, &hnat);
+  GTK_WIDGET_GET_CLASS (bin)->adjust_size_request (GTK_WIDGET (bin), 
+                                                  GTK_ORIENTATION_HORIZONTAL, &hmin, &hnat);
+
+  GTK_WIDGET_GET_CLASS (bin)->get_preferred_height (GTK_WIDGET (bin), &vmin, &vnat);
+  GTK_WIDGET_GET_CLASS (bin)->adjust_size_request (GTK_WIDGET (bin), 
+                                                  GTK_ORIENTATION_VERTICAL, &vmin, &vnat);
+
+  gtk_widget_get_preferred_width (priv->child, &child_hmin, NULL);
+  gtk_widget_get_preferred_height (priv->child, &child_vmin, NULL);
+
+  *delta_h = hmin - child_hmin;
+  *delta_v = vmin - child_vmin;
+}
+
 static void
 gtk_bin_get_preferred_width (GtkWidget *widget,
                              gint      *minimum_width,
@@ -249,25 +287,25 @@ gtk_bin_get_preferred_width_for_height (GtkWidget *widget,
 {
   GtkBin *bin = GTK_BIN (widget);
   GtkBinPrivate *priv = bin->priv;
-  gint border_width;
+  gint    hdelta, vdelta, child_min, child_nat;
 
   *minimum_width = 0;
   *natural_width = 0;
 
-  border_width = gtk_bin_get_effective_border_width (bin);
-
   if (priv->child && gtk_widget_get_visible (priv->child))
     {
-      gint child_min, child_nat;
-      gtk_widget_get_preferred_width_for_height (priv->child, height - 2 * border_width,
+      get_child_padding_delta (bin, &hdelta, &vdelta);
+
+      gtk_widget_get_preferred_width_for_height (priv->child,
+                                                 height - vdelta,
                                                  &child_min, &child_nat);
 
-      *minimum_width = child_min;
-      *natural_width = child_nat;
+      if (minimum_width)
+       *minimum_width = child_min + hdelta;
+      
+      if (natural_width)
+       *natural_width = child_nat + hdelta;
     }
-
-  *minimum_width += 2 * border_width;
-  *natural_width += 2 * border_width;
 }
 
 static void
@@ -278,25 +316,25 @@ gtk_bin_get_preferred_height_for_width  (GtkWidget *widget,
 {
   GtkBin *bin = GTK_BIN (widget);
   GtkBinPrivate *priv = bin->priv;
-  gint border_width;
+  gint    hdelta, vdelta, child_min, child_nat;
 
   *minimum_height = 0;
   *natural_height = 0;
 
-  border_width = gtk_bin_get_effective_border_width (bin);
-
   if (priv->child && gtk_widget_get_visible (priv->child))
     {
-      gint child_min, child_nat;
-      gtk_widget_get_preferred_height_for_width (priv->child, width - 2 * border_width,
+      get_child_padding_delta (bin, &hdelta, &vdelta);
+
+      gtk_widget_get_preferred_height_for_width (priv->child,
+                                                 width - hdelta,
                                                  &child_min, &child_nat);
 
-      *minimum_height = child_min;
-      *natural_height = child_nat;
+      if (minimum_height)
+       *minimum_height = child_min + vdelta;
+      
+      if (natural_height)
+       *natural_height = child_nat + vdelta;
     }
-
-  *minimum_height += 2 * border_width;
-  *natural_height += 2 * border_width;
 }
 
 static void