Removing Element.rect.

samples/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.
 
 class PageState {
   final ObservableValue<int> current;
   final ObservableValue<int> target;
   final ObservableValue<int> length;
   PageState() :
     current = new ObservableValue<int>(0),
@@ skipping 98 matching lines @@
     // work reasonably well for both clicking and throwing. So for now, leave
     // the scroller configured the default way.
 
     // TODO(jacobr): use named arguments when available.
     scroller = new Scroller(
         _container,
         false /* verticalScrollEnabled */,
         true /* horizontalScrollEnabled */,
         true /* momementumEnabled */,
         () {
-          final completer = new Completer<Size>();
-          _container.rect.then((ElementRect rect) {
-            // Only view width matters.
-            completer.complete(new Size(_getViewLength(rect), 1));
-          });
-          return completer.future;
+          return new Size(_getViewLength(_container), 1);
         },
         Scroller.FAST_SNAP_DECELERATION_FACTOR);
 
     scroller.onDecelStart.add(_snapToPage);
     scroller.onScrollerDragEnd.add(_snapToPage);
     scroller.onContentMoved.add(_onContentMoved);
     return node;
   }
 
-  int _getViewLength(ElementRect rect) {
-    return _computePageSize(rect) * pages.length.value;
+  int _getViewLength(Element element) {
+    return _computePageSize(element) * pages.length.value;
   }
 
   // TODO(jmesserly): would be better to not have this code in enterDocument.
   // But we need computedStyle to read our CSS properties.
   void enterDocument() {
     contentView.node.computedStyle.then((CSSStyleDeclaration style) {
       _computeColumnGap(style);
 
       // Trigger a fake resize event so we measure our height.
       windowResized();
@@ skipping 32 matching lines @@
     return double.parse(value).round().toInt();
   }
 
   /** 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.
-    node.rect.then((ElementRect rect) {
-      contentView.node.style.height = '${rect.offset.height}px';
+    window.requestLayoutFrame(() {
+      contentView.node.style.height = '${node.offsetHeight}px';
     });
     _updatePageCount(null);
   }
 
   bool _updatePageCount(Callback callback) {
     int pageLength = 1;
-    _container.rect.then((ElementRect rect) {
-      if (rect.scroll.width > rect.offset.width) {
-        pageLength = (rect.scroll.width / _computePageSize(rect))
+    window.requestLayoutFrame(() {
+      if (_container.scrollWidth > _container.offsetWidth) {
+        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.
       if (oldPage == newPage) {
         pages.target.value = 0;
       }
       assert(newPage < pageLength);
       pages.target.value = newPage;
       pages.length.value = pageLength;
       if (callback != null) {
         callback();
       }
     });
   }
 
   void _onContentMoved(Event e) {
-    _container.rect.then((ElementRect rect) {
+    window.requestLayoutFrame(() {
       num current = scroller.contentOffset.x;
-      int pageSize = _computePageSize(rect);
+      int pageSize = _computePageSize(_container);
       pages.current.value = -(current / pageSize).round().toInt();
     });
   }
 
   void _snapToPage(Event e) {
     num current = scroller.contentOffset.x;
     num currentTarget = scroller.currentTarget.x;
-    _container.rect.then((ElementRect rect) {
-      int pageSize = _computePageSize(rect);
+    window.requestLayoutFrame(() {
+      int pageSize = _computePageSize(_container);
       int destination;
       num currentPageNumber = -(current / pageSize).round();
       num pageNumber = -currentTarget / pageSize;
       if (current == currentTarget) {
         // User was just static dragging so round to the nearest page.
         pageNumber = pageNumber.round();
       } else {
         if (currentPageNumber == pageNumber.round() &&
           (pageNumber - currentPageNumber).abs() > MIN_THROW_PAGE_FRACTION &&
-          -current + _viewportSize < _getViewLength(rect) && current < 0) {
+          -current + _viewportSize < _getViewLength(_container) &&
+          current < 0) {
           // The user is trying to throw so we want to round up to the
           // nearest page in the direction they are throwing.
           pageNumber = currentTarget < current
               ? currentPageNumber + 1 : currentPageNumber - 1;
         } else {
           pageNumber = pageNumber.round();
         }
       }
       pageNumber = pageNumber.toInt();
       num translate = -pageNumber * pageSize;
       pages.current.value = pageNumber;
       if (currentTarget != translate) {
         scroller.throwTo(translate, 0);
       } else {
         // Update the target page number when we are done animating.
         pages.target.value = pageNumber;
       }
     });
   }
 
-  int _computePageSize(ElementRect rect) {
+  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 = rect.offset.width;
+    _viewportSize = element.offsetWidth;
 
     // 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() {
-    _container.rect.then((ElementRect rect) {
-      int translate = -pages.target.value * _computePageSize(rect);
+    window.requestLayoutFrame(() {
+      int translate = -pages.target.value * _computePageSize(_container);
       scroller.throwTo(translate, 0);
     });
   }
 }