Some minor bug fixes and improvements (#74)

* Fixing bug when casting from IMutableBidirectionalGraph<TVertex, TEdge> to TGraph.

* Enabling FitButton in ZoomControl's ViewFinder.

Author: edgardozoppi

GraphX.Controls/Themes/Generic.xaml

@@ -313,7 +313,7 @@
                                             Orientation="Horizontal"
                                             IsEnabled="True"
                                             />
-                                    <Button IsEnabled="False" x:Name="FitButton" Command="graphx:ZoomControl.ResetZoom" ToolTip="Fit Content within Bounds" Width="20px" Height="20px" Margin="2,0"  Style="{StaticResource TransparentButton}">
+                                    <Button x:Name="FitButton" Command="graphx:ZoomControl.ResetZoom" ToolTip="Fit Content within Bounds" Width="20px" Height="20px" Margin="2,0"  Style="{StaticResource TransparentButton}">
                                         <Image Source="{StaticResource FitContentGlyph}" Margin="2"/>
                                     </Button>
                                     <Button x:Name="FillButton" Command="graphx:ZoomControl.Fill" ToolTip="Fill Bounds with Content" Width="20px" Height="20px" Margin="2,0"  Style="{StaticResource TransparentButton}">

GraphX.PCL.Logic/Models/AlgorithmFactory.cs

@@ -31,12 +31,8 @@ public ILayoutAlgorithm<TVertex, TEdge, TGraph> CreateLayoutAlgorithm(LayoutAlgo
             if (parameters == null) parameters = CreateLayoutParameters(newAlgorithmType);
             var graph = iGraph.CopyToGraph<TGraph, TVertex, TEdge>();
 
-            var tGraph = (IMutableBidirectionalGraph<TVertex, TEdge>) graph;
-            if (tGraph != null)
-            {
-                tGraph.RemoveEdgeIf(a => a.SkipProcessing == ProcessingOptionEnum.Exclude);
-                tGraph.RemoveVertexIf(a => a.SkipProcessing == ProcessingOptionEnum.Exclude);                
-            }
+            graph.RemoveEdgeIf(a => a.SkipProcessing == ProcessingOptionEnum.Exclude);
+            graph.RemoveVertexIf(a => a.SkipProcessing == ProcessingOptionEnum.Exclude);
 
             switch (newAlgorithmType)
             {
@@ -230,18 +226,18 @@ public IExternalEdgeRouting<TVertex, TEdge> CreateEdgeRoutingAlgorithm(EdgeRouti
         {
             //if (Rectangles == null) return null;
             if (parameters == null) parameters = CreateEdgeRoutingParameters(newAlgorithmType);
-            IMutableBidirectionalGraph<TVertex, TEdge> graph = iGraph.CopyToBidirectionalGraph();
+			var graph = iGraph.CopyToGraph<TGraph, TVertex, TEdge>();
             graph.RemoveEdgeIf(a => a.SkipProcessing == ProcessingOptionEnum.Exclude);
             graph.RemoveVertexIf(a => a.SkipProcessing == ProcessingOptionEnum.Exclude);
 
             switch (newAlgorithmType)
             {
                 case EdgeRoutingAlgorithmTypeEnum.SimpleER:
-                    return new SimpleEdgeRouting<TVertex, TEdge,  TGraph>((TGraph)graph, positions, rectangles, parameters);
+                    return new SimpleEdgeRouting<TVertex, TEdge,  TGraph>(graph, positions, rectangles, parameters);
                 case EdgeRoutingAlgorithmTypeEnum.Bundling:
-                    return new BundleEdgeRouting<TVertex, TEdge, TGraph>(graphArea, (TGraph)graph, positions, rectangles, parameters);
+                    return new BundleEdgeRouting<TVertex, TEdge, TGraph>(graphArea, graph, positions, rectangles, parameters);
                 case EdgeRoutingAlgorithmTypeEnum.PathFinder:
-                    return new PathFinderEdgeRouting<TVertex, TEdge, TGraph>((TGraph)graph, positions, rectangles, parameters);
+                    return new PathFinderEdgeRouting<TVertex, TEdge, TGraph>(graph, positions, rectangles, parameters);
                 default:
                     return null;
             }