[clutter] box-layout: Fix allocation brain farts

[Emmanuele Bassi <ebassi src gnome org>]

commit f854619bc976775af7c2a7ab7d52cec7cc0c490c
Author: Emmanuele Bassi <ebassi linux intel com>
Date:   Tue Feb 14 15:39:15 2012 +0000

    box-layout: Fix allocation brain farts
    
    The allocation code for BoxLayout contains a sequence of brain farts
    that make it barely working since the synchronization of the layout
    algorithm to the one in GtkBox.
    
    The origin of the layout is inverted, and it doesn't take into
    consideration a modified allocation origin (for actors the provide
    padding or margin).
    
    The pack-start property is broken, and it only works because we walk the
    children list backwards; this horribly breaks when a child changes
    visibility. Plus, we count invisible children, which leads to
    allocations getting insane origins (either close to -MAX_FLOAT or
    MAX_FLOAT).
    
    Finally, the allocation is applied twice even for non-animated cases.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=669291

 clutter/clutter-box-layout.c |   67 ++++++++++++++++++++++++-----------------
 1 files changed, 39 insertions(+), 28 deletions(-)
---
diff --git a/clutter/clutter-box-layout.c b/clutter/clutter-box-layout.c
index f8c11cc..4d18585 100644
--- a/clutter/clutter-box-layout.c
+++ b/clutter/clutter-box-layout.c
@@ -474,9 +474,9 @@ clutter_box_layout_set_container (ClutterLayoutManager *layout,
       /* we need to change the :request-mode of the container
        * to match the orientation
        */
-      request_mode = (priv->is_vertical
-                      ? CLUTTER_REQUEST_HEIGHT_FOR_WIDTH
-                      : CLUTTER_REQUEST_WIDTH_FOR_HEIGHT);
+      request_mode = priv->is_vertical
+                   ? CLUTTER_REQUEST_HEIGHT_FOR_WIDTH
+                   : CLUTTER_REQUEST_WIDTH_FOR_HEIGHT;
       clutter_actor_set_request_mode (CLUTTER_ACTOR (priv->container),
                                       request_mode);
     }
@@ -655,6 +655,12 @@ allocate_box_child (ClutterBoxLayout       *self,
                                                 child);
   box_child = CLUTTER_BOX_CHILD (meta);
 
+  CLUTTER_NOTE (LAYOUT, "Allocation for %s { %.2f, %.2f, %.2f, %.2f }",
+                _clutter_actor_get_debug_name (child),
+                child_box->x1, child_box->y1,
+                child_box->x2 - child_box->x1,
+                child_box->y2 - child_box->y1);
+
   clutter_actor_allocate_align_fill (child, child_box,
                                      get_box_alignment_factor (box_child->x_align),
                                      get_box_alignment_factor (box_child->y_align),
@@ -684,7 +690,7 @@ allocate_box_child (ClutterBoxLayout       *self,
           box_child->last_allocation = final_child_box;
           box_child->has_last_allocation = TRUE;
 
-          goto do_allocate;
+          return;
         }
 
       start = &box_child->last_allocation;
@@ -704,16 +710,17 @@ allocate_box_child (ClutterBoxLayout       *self,
                     final_child_box.x2, final_child_box.y2,
                     end.x1, end.y1,
                     end.x2, end.y2);
+
+      clutter_actor_allocate (child, &final_child_box, flags);
     }
   else
     {
       /* store the allocation for later animations */
       box_child->last_allocation = final_child_box;
       box_child->has_last_allocation = TRUE;
-    }
 
-do_allocate:
-  clutter_actor_allocate (child, &final_child_box, flags);
+      return;
+    }
 }
 
 static void
@@ -915,6 +922,11 @@ clutter_box_layout_allocate (ClutterLayoutManager   *layout,
 
   count_expand_children (layout, container, &nvis_children, &nexpand_children);
 
+  CLUTTER_NOTE (LAYOUT, "BoxLayout for %s: visible=%d, expand=%d",
+                _clutter_actor_get_debug_name (CLUTTER_ACTOR (container)),
+                nvis_children,
+                nexpand_children);
+
   /* If there is no visible child, simply return. */
   if (nvis_children <= 0)
     return;
@@ -1016,33 +1028,30 @@ clutter_box_layout_allocate (ClutterLayoutManager   *layout,
   /* Allocate child positions. */
   if (priv->is_vertical)
     {
-      child_allocation.x1 = 0.0;
+      child_allocation.x1 = box->x1;
       child_allocation.x2 = MAX (1.0, box->x2 - box->x1);
       if (priv->is_pack_start)
-        y = 0.0;
-      else
         y = box->y2 - box->y1;
+      else
+        y = box->y1;
     }
   else
     {
-      child_allocation.y1 = 0.0;
+      child_allocation.y1 = box->y1;
       child_allocation.y2 = MAX (1.0, box->y2 - box->y1);
       if (priv->is_pack_start)
-        x = 0.0;
+        x = box->x2 - box->x1;
       else
-        x = 0.0 + box->x2 - box->x1;
+        x = box->x1;
     }
 
-  i = clutter_actor_get_n_children (actor);
-  for (child = clutter_actor_get_last_child (actor);
-       child != NULL;
-       child = clutter_actor_get_previous_sibling (child))
+  i = 0;
+  clutter_actor_iter_init (&iter, actor);
+  while (clutter_actor_iter_next (&iter, &child))
     {
       ClutterLayoutMeta *meta;
       ClutterBoxChild *box_child;
 
-      i -= 1;
-
       /* If widget is not visible, skip it. */
       if (!CLUTTER_ACTOR_IS_VISIBLE (child))
         continue;
@@ -1095,22 +1104,22 @@ clutter_box_layout_allocate (ClutterLayoutManager   *layout,
 
           if (priv->is_pack_start)
             {
-              y += child_size + priv->spacing;
-            }
-          else
-            {
               y -= child_size + priv->spacing;
 
               child_allocation.y1 -= child_size;
               child_allocation.y2 -= child_size;
             }
+          else
+            {
+              y += child_size + priv->spacing;
+            }
         }
       else /* !priv->is_vertical */
         {
           if (box_child->x_fill)
             {
               child_allocation.x1 = x;
-              child_allocation.x2 = child_allocation.x1 + MAX (1, child_size);
+              child_allocation.x2 = child_allocation.x1 + MAX (1.0, child_size);
             }
           else
             {
@@ -1120,15 +1129,15 @@ clutter_box_layout_allocate (ClutterLayoutManager   *layout,
 
           if (priv->is_pack_start)
             {
-              x += child_size + priv->spacing;
-            }
-          else
-            {
               x -= child_size + priv->spacing;
 
               child_allocation.x1 -= child_size;
               child_allocation.x2 -= child_size;
             }
+          else
+            {
+              x += child_size + priv->spacing;
+            }
 
           if (is_rtl)
             {
@@ -1147,6 +1156,8 @@ clutter_box_layout_allocate (ClutterLayoutManager   *layout,
                             child,
                             &child_allocation,
                             flags);
+
+        i += 1;
     }
 }