--- a/doodle/dia/tool.d	Sun Aug 08 21:56:54 2010 +0930
+++ b/doodle/dia/tool.d	Sun Aug 08 22:01:54 2010 +0930
@@ -32,17 +32,17 @@
     abstract void stop(IToolStack tool_stack);
     */
 
-    bool handleButtonPress(scope Viewport viewport, in ButtonEvent event) { return false; }
-    bool handleButtonRelease(scope Viewport viewport, in ButtonEvent event) { return false; }
-    bool handleMotion(scope Viewport viewport, in MotionEvent event) { return false; }
-    bool handleScroll(scope Viewport viewport, in ScrollEvent event) { return false; }
+    bool handleButtonPress(scope IViewport viewport, in ButtonEvent event) { return false; }
+    bool handleButtonRelease(scope IViewport viewport, in ButtonEvent event) { return false; }
+    bool handleMotion(scope IViewport viewport, in MotionEvent event) { return false; }
+    bool handleScroll(scope IViewport viewport, in ScrollEvent event) { return false; }
     //bool handleEnter(scope viewport, CrossingEvent event) { return false; }
     //bool handleLeave(scope viewport, CrossingEvent event) { return false; }
     //bool handleFocusIn(scope viewport, FocusEvent event) { return false; }
     //bool handleFocusOut(scope viewport, FocusEvent event) { return false; }
-    bool handleKeyPress(scope Viewport viewport, in KeyEvent event) { return false; }
-    bool handleKeyRelease(scope Viewport viewport, in KeyEvent event) { return false; }
+    bool handleKeyPress(scope IViewport viewport, in KeyEvent event) { return false; }
+    bool handleKeyRelease(scope IViewport viewport, in KeyEvent event) { return false; }
 
-    void draw(in Viewport viewport,
+    void draw(in IViewport viewport,
               in Rectangle pixelDamage, scope Context pixelCr) const { }
 }