Updated charted DEP to 0.4.X

packages/charted/lib/charts/src/chart_state_impl.dart

 //
 // Copyright 2014 Google Inc. All rights reserved.
 //
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file or at
 // https://developers.google.com/open-source/licenses/bsd
 //
 
 part of charted.charts;
 
 ///
 /// Model that maintains state of each visualization item. Each entry in the
 /// legend is considered one visualization item.
 /// - In [CartesianArea] it is always a column.
 /// - In [LayoutArea] renders choose either columns or rows.
 ///
 class DefaultChartStateImpl extends ChangeNotifier implements ChartState {
   final bool isMultiSelect;
   final bool isMultiHighlight;
   final bool isSelectOrHighlight;
   final bool supportColumnSelection;
   final bool supportColumnPreview;
   final bool supportValueHighlight;
   final bool supportValueHover;
 
   LinkedHashSet<int> hidden = new LinkedHashSet<int>();
 
   LinkedHashSet<int> selection = new LinkedHashSet<int>();
-  LinkedHashSet<Pair<int, int>> highlights =
-      new LinkedHashSet<Pair<int, int>>();
+  LinkedHashSet<Pair<int, int>> highlights = new LinkedHashSet<Pair<int, int>>();
 
   Pair<int, int> _hovered;
   int _preview;
 
   DefaultChartStateImpl(
       {this.supportColumnSelection: true,
       this.supportColumnPreview: true,
       this.supportValueHighlight: true,
       this.supportValueHover: true,
       this.isMultiSelect: false,
       this.isMultiHighlight: false,
       this.isSelectOrHighlight: true});
 
   set hovered(Pair<int, int> value) {
     if (!this.supportValueHover) return null;
     if (value != _hovered) {
       _hovered = value;
       notifyChange(new ChartHoverChangeRecord(_hovered));
     }
-    return value;
   }
 
   Pair<int, int> get hovered => _hovered;
 
   set preview(int value) {
     if (!this.supportColumnPreview) return null;
     if (value != _preview) {
       _preview = value;
       notifyChange(new ChartPreviewChangeRecord(_preview));
     }
-    return value;
   }
 
   int get preview => _preview;
 
   bool unhide(int id) {
     if (hidden.contains(id)) {
       hidden.remove(id);
       notifyChange(new ChartVisibilityChangeRecord(unhide: id));
     }
     return true;
@@ skipping 36 matching lines @@
 
   bool highlight(int column, int row) {
     if (!this.supportValueHighlight) return false;
     if (!isHighlighted(column, row)) {
       if (!isMultiHighlight) {
         highlights.clear();
       }
       if (isSelectOrHighlight) {
         selection.clear();
       }
-      var item = new Pair(column, row);
+      var item = new Pair<int, int>(column, row);
       highlights.add(item);
       notifyChange(new ChartHighlightChangeRecord(add: item));
     }
     return true;
   }
 
   bool unhighlight(int column, int row) {
     if (isHighlighted(column, row)) {
-      var item = new Pair(column, row);
+      var item = new Pair<int, int>(column, row);
       highlights.remove(item);
       notifyChange(new ChartHighlightChangeRecord(remove: item));
     }
     return false;
   }
 
   bool isHighlighted(int column, int row) =>
       highlights.any((x) => x.first == column && x.last == row);
 }