Converting Element.client*, offset* and Screen.avail* over to Rects

samples/swarm/swarm_ui_lib/touch/Scroller.dart

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of touch;
 
 /**
  * Implementation of a custom scrolling behavior.
  * This behavior overrides native scrolling for an area. This area can be a
  * single defined part of a page, the entire page, or several different parts
@@ skipping 542 matching lines @@
    * and maxPoint allowed for scrolling.
    */
   void _resize(Callback callback) {
     window.setImmediate(() {
       if (_lookupContentSizeDelegate != null) {
         _contentSize = _lookupContentSizeDelegate();
       } else {
         _contentSize = new Size(_element.scrollWidth, _element.scrollHeight);
       }
 
-      _scrollSize = new Size(_frame.offsetWidth,
-                             _frame.offsetHeight);
+      _scrollSize = new Size(_frame.offset.width,
+                             _frame.offset.height);
       Size adjusted = _getAdjustedContentSize();
       _maxPoint = new Coordinate(-_maxOffset.x, -_maxOffset.y);
       _minPoint = new Coordinate(
           Math.min(
               _scrollSize.width - adjusted.width + _minOffset.x, _maxPoint.x),
           Math.min(
               _scrollSize.height - adjusted.height + _minOffset.y, _maxPoint.y));
       callback();
     });
   }
@@ skipping 109 matching lines @@
   static const SCROLLER_END = "scroller:scroll_end";
   static const DRAG_END = "scroller:drag_end";
   static const CONTENT_MOVED = "scroller:content_moved";
   static const DECEL_START = "scroller:decel_start";
 }
 
 class ScrollerScrollTechnique {
   static const TRANSFORM_3D = 1;
   static const RELATIVE_POSITIONING = 2;
 }