centerlayout: Fix measuring in presence of baselines

The measure logic (unlike the allocation logic) was enforcing strict
baseline alignment of child widgets even if no child widget had valign
set to baseline. This was causing GtkCenterLayout to request more size
than it actually needed.

Instead, bring the logic closer to that of GtkBoxLayout by introducing
explicit have_baseline and align_baseline variables. We track and report
baseline if have_baseline gets set, but it only affects our reported
minimum and natural sizes if align_baseline ends up set, which happens
if there's a child widget that has valign set to either one of the two
baseline values, and itself reports a valid baseline.

Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>

diff --git a/gtk/gtkcenterlayout.c b/gtk/gtkcenterlayout.c
index 2660a4d47cc7d16583fba4dbb1bd99de139bbb22..a01522308d7db535fc825debf28ea298fe65c000 100644 (file)
--- a/gtk/gtkcenterlayout.c
+++ b/gtk/gtkcenterlayout.c
@@ -282,6 +282,8 @@ gtk_center_layout_measure_opposite (GtkCenterLayout *self,
   int total_nat, above_nat, below_nat;
   GtkWidget *child[3];
   GtkRequestedSize sizes[3];
+  gboolean have_baseline = FALSE;
+  gboolean align_baseline = FALSE;
   int i;
 
   child[0] = self->start_widget;
@@ -305,27 +307,33 @@ gtk_center_layout_measure_opposite (GtkCenterLayout *self,
                           &child_min, &child_nat,
                           &child_min_baseline, &child_nat_baseline);
 
-      if (child_min_baseline >= 0)
+      total_min = MAX (total_min, child_min);
+      total_nat = MAX (total_nat, child_nat);
+
+      if (orientation == GTK_ORIENTATION_VERTICAL && child_min_baseline >= 0)
         {
+          have_baseline = TRUE;
+          if (gtk_widget_get_valign (child[i]) == GTK_ALIGN_BASELINE_FILL ||
+              gtk_widget_get_valign (child[i]) == GTK_ALIGN_BASELINE_CENTER)
+            align_baseline = TRUE;
+
           below_min = MAX (below_min, child_min - child_min_baseline);
           above_min = MAX (above_min, child_min_baseline);
           below_nat = MAX (below_nat, child_nat - child_nat_baseline);
           above_nat = MAX (above_nat, child_nat_baseline);
         }
-      else
-        {
-          total_min = MAX (total_min, child_min);
-          total_nat = MAX (total_nat, child_nat);
-        }
    }
 
-  if (above_min >= 0)
+  if (have_baseline)
     {
       int min_baseline = -1;
       int nat_baseline = -1;
 
-      total_min = MAX (total_min, above_min + below_min);
-      total_nat = MAX (total_nat, above_nat + below_nat);
+      if (align_baseline)
+        {
+          total_min = MAX (total_min, above_min + below_min);
+          total_nat = MAX (total_nat, above_nat + below_nat);
+        }
 
       switch (self->baseline_pos)
         {