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

samples/swarm/swarm_ui_lib/view/PagedViews.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 view;
 
 class PageState {
   final ObservableValue<int> current;
   final ObservableValue<int> target;
   final ObservableValue<int> length;
@@ skipping 166 matching lines @@
   }
 
   /** Watch for resize and update page count. */
   void windowResized() {
     // TODO(jmesserly): verify we aren't triggering unnecessary layouts.
 
     // The content needs to have its height explicitly set, or columns don't
     // flow to the right correctly. So we copy our own height and set the height
     // of the content.
     window.setImmediate(() {
-      contentView.node.style.height = '${node.offsetHeight}px';
+      contentView.node.style.height = '${node.offset.height}px';
     });
     _updatePageCount(null);
   }
 
   bool _updatePageCount(Callback callback) {
     int pageLength = 1;
     window.setImmediate(() {
-      if (_container.scrollWidth > _container.offsetWidth) {
+      if (_container.scrollWidth > _container.offset.width) {
         pageLength = (_container.scrollWidth / _computePageSize(_container))
             .ceil().toInt();
       }
       pageLength = Math.max(pageLength, 1);
 
       int oldPage = pages.target.value;
       int newPage = Math.min(oldPage, pageLength - 1);
 
       // Hacky: make sure a change event always fires.
       // This is so we adjust the 3d transform after resize.
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         // Update the target page number when we are done animating.
         pages.target.value = pageNumber;
       }
     });
   }
 
   int _computePageSize(Element element) {
     // Hacky: we need to duplicate the way the columns are being computed,
     // including rounding, to figure out how far to translate the div.
     // See http://www.w3.org/TR/css3-multicol/#column-width
-    _viewportSize = element.offsetWidth;
+    _viewportSize = element.offset.width;
 
     // Figure out how many columns we're rendering.
     // The algorithm ensures we're bigger than the specified min size.
     int perPage = Math.max(1,
         (_viewportSize + _columnGap) ~/ (_columnWidth + _columnGap));
 
     // Divide up the viewport between the columns.
     int columnSize = (_viewportSize - (perPage - 1) * _columnGap) ~/ perPage;
 
     // Finally, compute how big each page is, and how far to translate.
     return perPage * (columnSize + _columnGap);
   }
 
   void _onPageSelected() {
     window.setImmediate(() {
       int translate = -pages.target.value * _computePageSize(_container);
       scroller.throwTo(translate, 0);
     });
   }
 }