feature: mark deleted repository and auto remove it after scan default clone dir (#576)

src/ViewModels/Preference.cs

@@ -453,6 +453,13 @@ namespace SourceGit.ViewModels
             Save();
         }
 
+        public void AutoRemoveInvalidNode()
+        {
+            var changed = RemoveInvalidRepositoriesRecursive(RepositoryNodes);
+            if (changed)
+                Save();
+        }
+
         public void Save()
         {
             if (_isLoading)
@@ -567,6 +574,27 @@ namespace SourceGit.ViewModels
             return false;
         }
 
+        private bool RemoveInvalidRepositoriesRecursive(List<RepositoryNode> collection)
+        {
+            bool changed = false;
+            
+            for (int i = collection.Count - 1; i >= 0; i--)
+            {
+                var node = collection[i];
+                if (node.IsInvalid)
+                {
+                    collection.RemoveAt(i);
+                    changed = true;
+                }
+                else if (!node.IsRepository)
+                {
+                    changed |= RemoveInvalidRepositoriesRecursive(node.SubNodes);
+                }
+            }
+
+            return changed;
+        }
+
         private static Preference _instance = null;
         private static bool _isLoading = false;
 

src/ViewModels/RepositoryNode.cs

@@ -1,4 +1,5 @@
 using System.Collections.Generic;
+using System.IO;
 using System.Text.Json.Serialization;
 
 using CommunityToolkit.Mvvm.ComponentModel;
@@ -48,6 +49,12 @@ namespace SourceGit.ViewModels
             set => SetProperty(ref _isVisible, value);
         }
 
+        [JsonIgnore]
+        public bool IsInvalid
+        {
+            get => _isRepository && !Directory.Exists(_id);
+        }
+
         [JsonIgnore]
         public int Depth
         {

src/ViewModels/ScanRepositories.cs

@@ -56,12 +56,9 @@ namespace SourceGit.ViewModels
                             var group = FindOrCreateGroupRecursive(Preference.Instance.RepositoryNodes, relative);
                             Preference.Instance.FindOrAddNodeByRepositoryPath(f, group, false);
                         }
-                        else
-                        {
-                            // Should not happen.
-                        }
                     }
 
+                    Preference.Instance.AutoRemoveInvalidNode();
                     Welcome.Instance.Refresh();
                 });
 

src/Views/Welcome.axaml

@@ -131,10 +131,15 @@
                               IsChecked="{Binding IsExpanded}"
                               IsVisible="{Binding !IsRepository}"/>
 
-                <TextBlock Grid.Column="2" 
+                <StackPanel Grid.Column="2" Orientation="Horizontal">
-                           Classes="primary" 
+                  <TextBlock Classes="primary" VerticalAlignment="Center" Text="{Binding Name}"/>
-                           VerticalAlignment="Center" 
+                  <Path Margin="2,0,0,0"
-                           Text="{Binding Name}"/>
+                        Width="12" Height="12"
+                        Data="{StaticResource Icons.Error}"
+                        Fill="Orange"
+                        IsVisible="{Binding IsInvalid}"/>
+                </StackPanel>
+                
                 <TextBlock Grid.Column="3"
                            Classes="primary"
                            Margin="8,0"