From 7c118a43c658cd1c487e00d56eab66a8888855b4 Mon Sep 17 00:00:00 2001
From: MountainFlash <gurjar.minshu@gmail.com>
Date: Wed, 6 Oct 2021 21:24:43 +0530
Subject: [PATCH] go to last cursor location

---
 FModel/Framework/NavigationList.cs            | 34 ++++++++++++++
 FModel/ViewModels/CUE4ParseViewModel.cs       |  1 +
 .../Resources/Controls/AvalonEditor.xaml      |  6 +--
 .../Resources/Controls/AvalonEditor.xaml.cs   | 47 +++++++++++++++++--
 4 files changed, 81 insertions(+), 7 deletions(-)
 create mode 100644 FModel/Framework/NavigationList.cs

diff --git a/FModel/Framework/NavigationList.cs b/FModel/Framework/NavigationList.cs
new file mode 100644
index 00000000..7e32beea
--- /dev/null
+++ b/FModel/Framework/NavigationList.cs
@@ -0,0 +1,34 @@
+using System.Collections.Generic;
+
+namespace FModel.Framework
+{
+    public class NavigationList<T> : List<T>
+    {
+        private int _currentIndex = 0;
+        public int CurrentIndex
+        {
+            get
+            {
+                if (_currentIndex > Count - 1) { _currentIndex = Count - 1; }
+                if (_currentIndex < 0) { _currentIndex = 0; }
+                return _currentIndex;
+            }
+            set { _currentIndex = value; }
+        }
+
+        public T MoveNext
+        {
+            get { _currentIndex++; return this[CurrentIndex]; }
+        }
+
+        public T MovePrevious
+        {
+            get { _currentIndex--; return this[CurrentIndex]; }
+        }
+
+        public T Current
+        {
+            get { return this[CurrentIndex]; }
+        }
+    }
+}
diff --git a/FModel/ViewModels/CUE4ParseViewModel.cs b/FModel/ViewModels/CUE4ParseViewModel.cs
index 877cabcc..3c95a135 100644
--- a/FModel/ViewModels/CUE4ParseViewModel.cs
+++ b/FModel/ViewModels/CUE4ParseViewModel.cs
@@ -357,6 +357,7 @@ namespace FModel.ViewModels
             await _threadWorkerView.Begin(cancellationToken =>
             {
                 var hotfixes = ApplicationService.ApiEndpointView.BenbotApi.GetHotfixes(cancellationToken, Provider.GetLanguageCode(UserSettings.Default.AssetLanguage));
+                if (hotfixes == null) return;
 
                 foreach (var entries in hotfixes)
                 {
diff --git a/FModel/Views/Resources/Controls/AvalonEditor.xaml b/FModel/Views/Resources/Controls/AvalonEditor.xaml
index f45de016..e1b45d20 100644
--- a/FModel/Views/Resources/Controls/AvalonEditor.xaml
+++ b/FModel/Views/Resources/Controls/AvalonEditor.xaml
@@ -17,7 +17,7 @@
             <RowDefinition Height="Auto" />
             <RowDefinition Height="*" />
         </Grid.RowDefinitions>
-        
+
         <Grid Grid.Row="0" Margin="3 0" HorizontalAlignment="Right" Width="500">
             <Grid.Style>
                 <Style TargetType="{x:Type Grid}">
@@ -34,7 +34,7 @@
                 <ColumnDefinition Width="Auto" />
                 <ColumnDefinition Width="Auto" />
             </Grid.ColumnDefinitions>
-            
+
             <Grid Grid.Column="0" ZIndex="1" HorizontalAlignment="Left" Margin="5 2 0 0">
                 <Viewbox Width="16" Height="16">
                     <Canvas Width="24" Height="24">
@@ -113,6 +113,6 @@
         <avalonEdit:TextEditor x:Name="MyAvalonEditor" Grid.Row="0" Grid.RowSpan="2" SyntaxHighlighting="{Binding Highlighter}" Document="{Binding Document}"
                                FontFamily="Consolas" FontSize="{Binding FontSize}" IsReadOnly="True" ShowLineNumbers="True" Foreground="#DAE5F2"
                                Background="{DynamicResource {x:Static adonisUi:Brushes.Layer3BackgroundBrush}}" PreviewMouseWheel="OnPreviewMouseWheel"
-                               TextChanged="OnTextChanged" MouseHover="OnMouseHover" MouseHoverStopped="OnMouseHoverStopped" />
+                               TextChanged="OnTextChanged" MouseHover="OnMouseHover" MouseHoverStopped="OnMouseHoverStopped" PreviewMouseUp="OnMouseRelease" />
     </Grid>
 </UserControl>
diff --git a/FModel/Views/Resources/Controls/AvalonEditor.xaml.cs b/FModel/Views/Resources/Controls/AvalonEditor.xaml.cs
index e90ffc22..385b697c 100644
--- a/FModel/Views/Resources/Controls/AvalonEditor.xaml.cs
+++ b/FModel/Views/Resources/Controls/AvalonEditor.xaml.cs
@@ -1,9 +1,11 @@
-using System;
+using System;
+using System.Collections.Generic;
 using System.Text.RegularExpressions;
 using System.Windows;
 using System.Windows.Input;
 using System.Windows.Media;
 using FModel.Extensions;
+using FModel.Framework;
 using FModel.ViewModels;
 using ICSharpCode.AvalonEdit;
 using SkiaSharp;
@@ -20,12 +22,14 @@ namespace FModel.Views.Resources.Controls
         private readonly Regex _hexColorRegex = new("\"Hex\": \"(?'target'[0-9A-Fa-f]{3,8})\"$",
             RegexOptions.Compiled | RegexOptions.Singleline | RegexOptions.IgnoreCase | RegexOptions.CultureInvariant);
         private readonly System.Windows.Controls.ToolTip _toolTip = new();
+        private readonly NavigationList<int> _caretList = new();
+        private bool _ignoreCaret = true;
 
         public AvalonEditor()
         {
             CommandBindings.Add(new CommandBinding(NavigationCommands.Search, (_, e) => FindNext(e.Parameter != null)));
             InitializeComponent();
-            
+
             YesWeEditor = MyAvalonEditor;
             YesWeSearch = WpfSuckMyDick;
             MyAvalonEditor.TextArea.TextView.ElementGenerators.Add(new GamePathElementGenerator());
@@ -49,6 +53,23 @@ namespace FModel.Views.Resources.Controls
                     FindNext();
                     dc.SearchUp = old;
                     break;
+                case Key.System: // Alt
+                    if (Keyboard.IsKeyDown(Key.Left))
+                    {
+                        if (_caretList.Count == 0)
+                            return;
+                        var movep = _caretList.MovePrevious;
+                        MyAvalonEditor.CaretOffset = movep;
+                        MyAvalonEditor.TextArea.Caret.BringCaretToView();
+                    } else if ((Keyboard.IsKeyDown(Key.Right)))
+                    {
+                        if (_caretList.Count == 0)
+                            return;
+                        var move = _caretList.MoveNext;
+                        MyAvalonEditor.CaretOffset = move;
+                        MyAvalonEditor.TextArea.Caret.BringCaretToView();
+                    }
+                    break;
             }
         }
 
@@ -88,7 +109,8 @@ namespace FModel.Views.Resources.Controls
             if (sender is not TextEditor avalonEditor || DataContext is not TabItem tabItem ||
                 avalonEditor.Document == null || string.IsNullOrEmpty(avalonEditor.Document.Text))
                 return;
-            
+            _caretList.Clear();
+            _ignoreCaret = true;
             avalonEditor.Document.FileName = tabItem.Directory + '/' + tabItem.Header.SubstringBeforeLast('.');
             if (!tabItem.ShouldScroll) return;
 
@@ -102,7 +124,7 @@ namespace FModel.Views.Resources.Controls
         {
             if (DataContext is not TabItem tabItem || Keyboard.Modifiers != ModifierKeys.Control)
                 return;
-            
+
             var fontSize = tabItem.FontSize + e.Delta / 50.0;
             tabItem.FontSize = fontSize switch
             {
@@ -186,5 +208,22 @@ namespace FModel.Views.Resources.Controls
         {
             ((TabItem) DataContext).HasSearchOpen = false;
         }
+
+        private void SaveCaretLoc(int offset)
+        {
+            if (_ignoreCaret) { _ignoreCaret = false; return;} // first always point to the end of the file for some reason
+            if (_caretList.Count >= 10)
+                _caretList.RemoveAt(0);
+            if (!_caretList.Contains(offset))
+            {
+                _caretList.Add(offset);
+                _caretList.CurrentIndex = _caretList.Count-1;
+            }
+        }
+
+        private void OnMouseRelease(object sender, MouseButtonEventArgs e)
+        {
+            SaveCaretLoc(MyAvalonEditor.CaretOffset);
+        }
     }
 }
\ No newline at end of file