[gtk] box: Use widget child list when computing size request

[Timm Bäder <baedert src gnome org>]

commit 3a4c6c18b30fadb0ffb24564b99cb9b88146a900
Author: Timm Bäder <mail baedert org>
Date:   Tue Feb 6 22:19:30 2018 +0100

    box: Use widget child list when computing size request
    
    Contrary to what the comments in this function might suggest, it does
    not actually do anything about child positions, child child sizes. So,
    packing doesn't matter and we don't need to iterate over all child
    widgets twice.

 gtk/gtkbox.c | 119 +++++++++++++++++++++++++----------------------------------
 1 file changed, 50 insertions(+), 69 deletions(-)
---
diff --git a/gtk/gtkbox.c b/gtk/gtkbox.c
index fac5464e53..927093e458 100644
--- a/gtk/gtkbox.c
+++ b/gtk/gtkbox.c
@@ -1041,8 +1041,8 @@ gtk_box_compute_size_for_opposing_orientation (GtkBox *box,
                                               gint   *natural_baseline)
 {
   GtkBoxPrivate    *private = gtk_box_get_instance_private (box);
-  GtkBoxChild      *child;
-  GList            *children;
+  GtkWidget        *widget = GTK_WIDGET (box);
+  GtkWidget        *child;
   gint              nvis_children;
   gint              nexpand_children;
   gint              computed_minimum = 0, computed_natural = 0;
@@ -1050,7 +1050,6 @@ gtk_box_compute_size_for_opposing_orientation (GtkBox *box,
   gint              computed_minimum_below = 0, computed_natural_below = 0;
   gint              computed_minimum_baseline = -1, computed_natural_baseline = -1;
   GtkRequestedSize *sizes;
-  GtkPackType       packing;
   gint              extra_space, size_given_to_child, i;
   gint              children_minimum_size = 0;
   gint              child_size, child_minimum, child_natural;
@@ -1069,22 +1068,19 @@ gtk_box_compute_size_for_opposing_orientation (GtkBox *box,
   extra_space = avail_size - (nvis_children - 1) * spacing;
 
   /* Retrieve desired size for visible children */
-  for (i = 0, children = private->children; children; children = children->next)
+  for (i = 0, child = _gtk_widget_get_first_child (widget);
+       child != NULL;
+       child = _gtk_widget_get_next_sibling (child))
     {
-      child = children->data;
-
-      if (_gtk_widget_get_visible (child->widget))
+      if (_gtk_widget_get_visible (child))
        {
-          gtk_widget_measure (child->widget,
+          gtk_widget_measure (child,
                               private->orientation,
                               -1,
                               &sizes[i].minimum_size, &sizes[i].natural_size,
                               NULL, NULL);
 
           children_minimum_size += sizes[i].minimum_size;
-
-         sizes[i].data = child;
-
          i += 1;
        }
     }
@@ -1120,32 +1116,32 @@ gtk_box_compute_size_for_opposing_orientation (GtkBox *box,
     }
 
   have_baseline = FALSE;
-  /* Allocate child positions. */
-  for (packing = GTK_PACK_START; packing <= GTK_PACK_END; ++packing)
+  for (i = 0, child = _gtk_widget_get_first_child (widget);
+       child != NULL;
+       child = _gtk_widget_get_next_sibling (child))
     {
-      for (i = 0, children = private->children;
-          children;
-          children = children->next)
-       {
-         child = children->data;
+      /* If widget is not visible, skip it. */
+      if (!_gtk_widget_get_visible (child))
+        continue;
 
-         /* If widget is not visible, skip it. */
-         if (!_gtk_widget_get_visible (child->widget))
-           continue;
+      /* Assign the child's size. */
+      if (private->homogeneous)
+        {
+          child_size = size_given_to_child;
 
-         /* If widget is packed differently skip it, but still increment i,
-          * since widget is visible and will be handled in next loop iteration.
-          */
-         if (child->pack != packing)
-           {
-             i++;
-             continue;
-           }
+          if (n_extra_widgets > 0)
+            {
+              child_size++;
+              n_extra_widgets--;
+            }
+        }
+      else
+        {
+          child_size = sizes[i].minimum_size;
 
-          /* Assign the child's size. */
-          if (private->homogeneous)
+          if (gtk_widget_compute_expand (child, private->orientation))
             {
-              child_size = size_given_to_child;
+              child_size += size_given_to_child;
 
               if (n_extra_widgets > 0)
                 {
@@ -1153,45 +1149,30 @@ gtk_box_compute_size_for_opposing_orientation (GtkBox *box,
                   n_extra_widgets--;
                 }
             }
-          else
-            {
-              child_size = sizes[i].minimum_size;
-
-              if (gtk_widget_compute_expand (child->widget, private->orientation))
-                {
-                  child_size += size_given_to_child;
-
-                  if (n_extra_widgets > 0)
-                    {
-                      child_size++;
-                      n_extra_widgets--;
-                    }
-                }
-            }
+        }
 
-          child_minimum_baseline = child_natural_baseline = -1;
-          /* Assign the child's position. */
-          gtk_widget_measure (child->widget,
-                              OPPOSITE_ORIENTATION (private->orientation),
-                              child_size,
-                              &child_minimum, &child_natural,
-                              &child_minimum_baseline, &child_natural_baseline);
+      child_minimum_baseline = child_natural_baseline = -1;
+      /* Assign the child's position. */
+      gtk_widget_measure (child,
+                          OPPOSITE_ORIENTATION (private->orientation),
+                          child_size,
+                          &child_minimum, &child_natural,
+                          &child_minimum_baseline, &child_natural_baseline);
 
-          if (child_minimum_baseline >= 0)
-            {
-              have_baseline = TRUE;
-              computed_minimum_below = MAX (computed_minimum_below, child_minimum - child_minimum_baseline);
-              computed_natural_below = MAX (computed_natural_below, child_natural - child_natural_baseline);
-              computed_minimum_above = MAX (computed_minimum_above, child_minimum_baseline);
-              computed_natural_above = MAX (computed_natural_above, child_natural_baseline);
-            }
-          else
-            {
-              computed_minimum = MAX (computed_minimum, child_minimum);
-              computed_natural = MAX (computed_natural, child_natural);
-            }
-         i += 1;
-       }
+      if (child_minimum_baseline >= 0)
+        {
+          have_baseline = TRUE;
+          computed_minimum_below = MAX (computed_minimum_below, child_minimum - child_minimum_baseline);
+          computed_natural_below = MAX (computed_natural_below, child_natural - child_natural_baseline);
+          computed_minimum_above = MAX (computed_minimum_above, child_minimum_baseline);
+          computed_natural_above = MAX (computed_natural_above, child_natural_baseline);
+        }
+      else
+        {
+          computed_minimum = MAX (computed_minimum, child_minimum);
+          computed_natural = MAX (computed_natural, child_natural);
+        }
+      i += 1;
     }
 
   if (have_baseline)