ScrolledWindow: Don’t req size for autohidden bars

POLICY_AUTOMATIC means scrollbars are only shown when needed, i.e. when
the size of the window is not large enough to show the entire child. So
when measuring the preferred size, such scrollbars should be ignored.

But measure() added size for *any* non-overlay scrollbar of the opposite
orientation, e.g. for horizontal size, it added the width of vscrollbar.
So we requested for child + bar, & having enough for child meant that the
policy hid the bar, leaving extra space empty below/right of the child.

Fix this by only adding size for such bars if they use POLICY_ALWAYS.

https://bugzilla.gnome.org/show_bug.cgi?id=778853

diff --git a/gtk/gtkscrolledwindow.c b/gtk/gtkscrolledwindow.c
index 51b90860f0de2de88f59dbbe4d456c05d93ac7e5..b68fd96b2f8994e3e72cce8bedf1dca78394d88f 100644 (file)
--- a/gtk/gtkscrolledwindow.c
+++ b/gtk/gtkscrolledwindow.c
@@ -1880,7 +1880,7 @@ gtk_scrolled_window_measure (GtkCssGadget   *gadget,
       minimum_req.width = MAX (minimum_req.width, hscrollbar_requisition.width + sborder.left + sborder.right);
       natural_req.width = MAX (natural_req.width, hscrollbar_requisition.width + sborder.left + sborder.right);
 
-      if (!priv->use_indicators)
+      if (!priv->use_indicators && priv->hscrollbar_policy == GTK_POLICY_ALWAYS)
        {
          minimum_req.height += scrollbar_spacing + hscrollbar_requisition.height;
          natural_req.height += scrollbar_spacing + hscrollbar_requisition.height;
@@ -1892,7 +1892,7 @@ gtk_scrolled_window_measure (GtkCssGadget   *gadget,
       minimum_req.height = MAX (minimum_req.height, vscrollbar_requisition.height + sborder.top + sborder.bottom);
       natural_req.height = MAX (natural_req.height, vscrollbar_requisition.height + sborder.top + sborder.bottom);
 
-      if (!priv->use_indicators)
+      if (!priv->use_indicators && priv->vscrollbar_policy == GTK_POLICY_ALWAYS)
        {
          minimum_req.width += scrollbar_spacing + vscrollbar_requisition.width;
          natural_req.width += scrollbar_spacing + vscrollbar_requisition.width;