Reimplemented Regex Description as TreeView

Author: Vogel612

RetailCoder.VBE/UI/RegexAssistant/RegexAssistant.xaml

@@ -8,6 +8,9 @@
              d:DesignHeight="300" Width="555"
              d:DataContext="{d:DesignInstance {x:Type assistant:RegexAssistantViewModel}, IsDesignTimeCreatable=False}">
     <UserControl.Resources>
+        <HierarchicalDataTemplate
+            x:Key="RecursiveData" DataType="TreeViewItem" ItemsSource="{Binding Items}">
+        </HierarchicalDataTemplate>
     </UserControl.Resources>
     <Grid>
         <ScrollViewer>
@@ -42,15 +45,11 @@
                                   Margin="15,5,5,5" IsChecked="{Binding IgnoreCaseFlag}"/>
                     </StackPanel>
                     <Label Content="{Resx ResxName=Rubberduck.UI.RubberduckUI, Key=RegexAssistant_DescriptionResultsLabel}"
-                   FontWeight="SemiBold" />
-
-                    <!--<RichTextBox x:Name="Results" HorizontalAlignment="Left" 
-                                 MinHeight="165" VerticalAlignment="Top" MinWidth="250"
-                                 Margin="15,5,5,5">
-                    </RichTextBox>-->
-                    <TextBlock MinHeight="165" VerticalAlignment="Top" MinWidth="250" TextWrapping="WrapWithOverflow"
-                                 Margin="15,5,5,5" Text="{Binding DescriptionResults, Mode=OneWay}"/>
-
+                        FontWeight="SemiBold" />
+                    
+                    <TreeView x:Name="treeView" ItemTemplate="{StaticResource RecursiveData}" 
+                              Height="145" VerticalAlignment="Stretch" Margin="15,10,10,10" HorizontalContentAlignment="Stretch"
+                              ItemsSource="{Binding ResultItems}"  />
                 </StackPanel>
             </Grid>
         </ScrollViewer>

RetailCoder.VBE/UI/RegexAssistant/RegexAssistantViewModel.cs

@@ -1,4 +1,8 @@
 using Rubberduck.RegexAssistant;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+using System.Windows.Controls;
 
 namespace Rubberduck.UI.RegexAssistant
 {
@@ -51,15 +55,38 @@ public string Pattern
         private bool _ignoreCaseFlag;
         private string _pattern;
 
+        private List<TreeViewItem> _resultItems;
+        public List<TreeViewItem> ResultItems
+        {
+            get
+            {
+                return _resultItems;
+            }
+            set
+            {
+                _resultItems = value;
+                OnPropertyChanged();
+            }
+        }
+
         private void RecalculateDescription()
         {
             if (_pattern.Equals(string.Empty))
             {
                 _description = "No Pattern given";
+                var results = new List<TreeViewItem>();
+                var rootTreeItem = new TreeViewItem();
+                rootTreeItem.Header = _description;
+                results.Add(rootTreeItem);
+                ResultItems = results;
                 return;
             }
-            _description = new Pattern(_pattern, _ignoreCaseFlag, _ignoreCaseFlag).Description;
-            base.OnPropertyChanged("DescriptionResults");
+            var pattern = new Pattern(_pattern, _ignoreCaseFlag, _ignoreCaseFlag);
+            //_description = pattern.Description;
+            var resultItems = new List<TreeViewItem>();
+            resultItems.Add(AsTreeViewItem((dynamic)pattern.RootExpression));
+            ResultItems = resultItems;
+            //base.OnPropertyChanged("DescriptionResults");
         }
 
         public string DescriptionResults
@@ -69,5 +96,53 @@ public string DescriptionResults
                 return _description;
             }
         }
+
+        private static TreeViewItem AsTreeViewItem(IRegularExpression expression)
+        {
+            var t = expression.GetType();
+
+            var result = new TreeViewItem();
+            result.Header = "Some unknown IRegularExpression subtype was in the view";
+            foreach (var subtree in expression.Subexpressions.Select(exp => AsTreeViewItem((dynamic)exp)))
+            {
+                result.Items.Add(subtree);
+            }
+            return result;
+        }
+
+        private static TreeViewItem AsTreeViewItem(ConcatenatedExpression expression)
+        {
+            var result = new TreeViewItem();
+            result.Header = expression.Description;
+            foreach (var subtree in expression.Subexpressions.Select(exp => AsTreeViewItem((dynamic)exp)))
+            {
+                result.Items.Add(subtree);
+            }
+            return result;
+        }
+
+        private static TreeViewItem AsTreeViewItem(AlternativesExpression expression)
+        {
+            var result = new TreeViewItem();
+            result.Header = expression.Description;
+            foreach (var subtree in expression.Subexpressions.Select(exp => AsTreeViewItem((dynamic)exp)))
+            {
+                result.Items.Add(subtree);
+            }
+            return result;
+        }
+
+        private static TreeViewItem AsTreeViewItem(SingleAtomExpression expression)
+        {
+            var result = new TreeViewItem();
+            result.Header = expression.Description;
+            // no other Atom has Subexpressions we care about
+            if (expression.Atom.GetType() == typeof(Group))
+            {
+                result.Items.Add(AsTreeViewItem((dynamic)((expression.Atom) as Group).Subexpression));
+            }
+            
+            return result;
+        }
     }
 }