#1: Added a message view model for creating the message layer displaying the NVG elements as messages.

Author: gisfromscratch

NVGViewer/NVGViewer/MainWindow.xaml

@@ -17,7 +17,8 @@
                       Grid.Row="0"
                       AllowDrop="True"
 					  LayerLoaded="FocusMapViewLayerLoaded"
-                      Drop="FocusMapViewDropped">
+                      Drop="FocusMapViewDropped"
+                      SpatialReferenceChanged="FocusMapViewSpatialReferenceChanged">
 			<esri:Map>
 				<esri:ArcGISTiledMapServiceLayer ID="Basemap"
 					ServiceUri="http://services.arcgisonline.com/ArcGIS/rest/services/World_Topo_Map/MapServer"/>

NVGViewer/NVGViewer/MainWindow.xaml.cs

@@ -17,6 +17,8 @@
 using Esri.ArcGISRuntime.Controls;
 using MahApps.Metro.Controls;
 using NVGViewer.ViewModel;
+using System;
+using System.ComponentModel;
 using System.Diagnostics;
 using System.Threading.Tasks;
 using System.Windows;
@@ -74,5 +76,13 @@ private void FocusMapViewDropped(object sender, DragEventArgs e)
                 mainViewModel.EndLoadingFiles();
             }, TaskScheduler.FromCurrentSynchronizationContext());
         }
+
+        private void FocusMapViewSpatialReferenceChanged(object sender, EventArgs e)
+        {
+            if (null != FocusMapView.SpatialReference)
+            {
+                // Create the message processor
+            }
+        }
     }
 }

NVGViewer/NVGViewer/NVGViewer.csproj

@@ -84,6 +84,7 @@
     </ApplicationDefinition>
     <Compile Include="Commands\LoadNvgFileCommand.cs" />
     <Compile Include="ViewModel\MainViewModel.cs" />
+    <Compile Include="ViewModel\MessageViewModel.cs" />
     <Compile Include="ViewModel\ViewModelLocator.cs" />
     <Page Include="MainWindow.xaml">
       <Generator>MSBuild:Compile</Generator>

NVGViewer/NVGViewer/ViewModel/MessageViewModel.cs

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2016 Jan Tschada
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+using Esri.ArcGISRuntime.Symbology.Specialized;
+using GalaSoft.MvvmLight;
+using NVG.Data;
+
+namespace NVGViewer.ViewModel
+{
+    /// <summary>
+    /// The view model for the messages.
+    /// </summary>
+    public class MessageViewModel : ViewModelBase
+    {
+        public MessageLayer CreateMessageLayer(NvgElement nvgElement)
+        {
+            // TODO: Create the message layer containing all messages of the NVG element
+            return null;
+        }
+    }
+}