[gtk+/overlay: 31/34] Implement RTL flipping for GtkOverlay

[Matthias Clasen <matthiasc src gnome org>]

commit 8acc61f7b6d5c1cd28b289f773a67feb0fc6f53d
Author: Matthias Clasen <mclasen redhat com>
Date:   Fri Jun 10 20:26:54 2011 -0400

    Implement RTL flipping for GtkOverlay

 gtk/gtkoverlay.c |   33 ++++++++++++++++++++++++++++++---
 1 files changed, 30 insertions(+), 3 deletions(-)
---
diff --git a/gtk/gtkoverlay.c b/gtk/gtkoverlay.c
index 9211332..e7a34ba 100644
--- a/gtk/gtkoverlay.c
+++ b/gtk/gtkoverlay.c
@@ -228,6 +228,21 @@ gtk_overlay_child_allocate (GtkWidget           *child,
   gtk_widget_size_allocate (child, child_allocation);
 }
 
+static GtkAlign
+effective_align (GtkAlign         align,
+                 GtkTextDirection direction)
+{
+  switch (align)
+    {
+    case GTK_ALIGN_START:
+      return direction == GTK_TEXT_DIR_RTL ? GTK_ALIGN_END : GTK_ALIGN_START;
+    case GTK_ALIGN_END:
+      return direction == GTK_TEXT_DIR_RTL ? GTK_ALIGN_START : GTK_ALIGN_END;
+    default:
+      return align;
+    }
+}
+
 static void
 gtk_overlay_size_allocate (GtkWidget     *widget,
                            GtkAllocation *allocation)
@@ -268,6 +283,8 @@ gtk_overlay_size_allocate (GtkWidget     *widget,
     {
       GtkRequisition req;
       GtkAllocation alloc, child_alloc;
+      GtkAlign halign;
+      GtkTextDirection direction;
 
       child = children->data;
 
@@ -277,10 +294,18 @@ gtk_overlay_size_allocate (GtkWidget     *widget,
 
       gtk_widget_get_preferred_size (child->widget, NULL, &req);
 
-      alloc.x = child->x_offset + main_alloc.x;
+      alloc.x = main_alloc.x;
       alloc.width = MIN (main_alloc.width, req.width);
 
-      switch (gtk_widget_get_halign (child->widget))
+      direction = gtk_widget_get_direction (child->widget);
+
+      if (direction == GTK_TEXT_DIR_RTL)
+        alloc.x -= child->x_offset;
+      else
+        alloc.x += child->x_offset;
+
+      halign = gtk_widget_get_halign (child->widget);
+      switch (effective_align (halign, direction))
         {
         case GTK_ALIGN_START:
         case GTK_ALIGN_FILL:
@@ -294,9 +319,11 @@ gtk_overlay_size_allocate (GtkWidget     *widget,
           break;
         }
 
-      alloc.y = child->y_offset + main_alloc.y;
+      alloc.y = main_alloc.y;
       alloc.height = MIN (main_alloc.height, req.height);
 
+      alloc.y += child->y_offset;
+
       switch (gtk_widget_get_valign (child->widget))
         {
         case GTK_ALIGN_START: