--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/MetroWpf/MetroWpf.Xaml/Transitions/Transition.cs	Tue Mar 20 20:18:35 2012 +0000
@@ -0,0 +1,65 @@
+using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Media;
+
+namespace MetroWpf.Xaml.Transitions
+{
+    // Base class for all transitions.
+    public class Transition : DependencyObject
+    {
+        public bool ClipToBounds
+        {
+            get { return (bool)GetValue(ClipToBoundsProperty); }
+            set { SetValue(ClipToBoundsProperty, value); }
+        }
+
+        public static readonly DependencyProperty ClipToBoundsProperty =
+            DependencyProperty.Register("ClipToBounds",
+                typeof(bool),
+                typeof(Transition),
+                new UIPropertyMetadata(false));
+
+        public bool IsNewContentTopmost
+        {
+            get { return (bool)GetValue(IsNewContentTopmostProperty); }
+            set { SetValue(IsNewContentTopmostProperty, value); }
+        }
+
+        public static readonly DependencyProperty IsNewContentTopmostProperty =
+            DependencyProperty.Register("IsNewContentTopmost",
+                typeof(bool),
+                typeof(Transition),
+                new UIPropertyMetadata(true));
+
+        // Called when an element is Removed from the TransitionPresenter's visual tree
+        protected internal virtual void BeginTransition(TransitionPresenter transitionElement, ContentPresenter oldContent, ContentPresenter newContent)
+        {
+            EndTransition(transitionElement, oldContent, newContent);
+        }
+
+        //Transitions should call this method when they are done
+        protected void EndTransition(TransitionPresenter transitionElement, ContentPresenter oldContent, ContentPresenter newContent)
+        {
+            OnTransitionEnded(transitionElement, oldContent, newContent);
+
+            transitionElement.OnTransitionCompleted();
+        }
+
+        //Transitions can override this to perform cleanup at the end of the transition
+        protected virtual void OnTransitionEnded(TransitionPresenter transitionElement, ContentPresenter oldContent, ContentPresenter newContent)
+        {
+        }
+
+        // Returns a clone of the element and hides it in the main tree
+        protected static Brush CreateBrush(ContentPresenter content)
+        {
+            ((Decorator)content.Parent).Visibility = Visibility.Hidden;
+
+            VisualBrush brush = new VisualBrush(content);
+            brush.ViewportUnits = BrushMappingMode.Absolute;
+            RenderOptions.SetCachingHint(brush, CachingHint.Cache);
+            RenderOptions.SetCacheInvalidationThresholdMinimum(brush, 40);
+            return brush;
+        }
+    }
+}