[hyena] massively improve rendering performance

[Gabriel Burt <gburt src gnome org>]

commit f877f08455db188319662e6fd8555345a1e82a57
Author: Aaron Bockover <abockover novell com>
Date:   Thu Jan 21 22:38:12 2010 -0500

    massively improve rendering performance
    
    While I have always oh so carefully computed proper clipping/damage
    rectangles which prevent unnecessary regions of the view being
    repainted on screen, I have never used this data to prevent walking
    the scene unnecessarily.
    
    That is, if we're not going to paint something on screen, don't
    go through the motions to lay it out in memory either.
    
    Face->Palm. Yet another thing that became more obvious and simple
    by moving to this awesome new layout system.
    
    I need to go for a beer run. Also, Sandy is a great listener.

 .../Hyena.Data.Gui/ListView/ListView_Rendering.cs  |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/src/Hyena.Gui/Hyena.Data.Gui/ListView/ListView_Rendering.cs b/src/Hyena.Gui/Hyena.Data.Gui/ListView/ListView_Rendering.cs
index 944e256..9497ef4 100644
--- a/src/Hyena.Gui/Hyena.Data.Gui/ListView/ListView_Rendering.cs
+++ b/src/Hyena.Gui/Hyena.Data.Gui/ListView/ListView_Rendering.cs
@@ -478,6 +478,8 @@ namespace Hyena.Data.Gui
 
                 if (model_row_index < 0 || model_row_index >= Model.Count) {
                     break;
+                } else if (!layout_child.Allocation.IntersectsWith (clip)) {
+                    continue;
                 }
 
                 if (Selection != null && Selection.Contains (model_row_index)) {