Added Undo List to hold freshly undid drawn Lines

SimpleDraw.csproj

@@ -13,13 +13,13 @@
     </ItemGroup>
 
     <ItemGroup>
-        <PackageReference Include="Avalonia" Version="11.2.4" />
-        <PackageReference Include="Avalonia.Desktop" Version="11.2.4" />
-        <PackageReference Include="Avalonia.Themes.Fluent" Version="11.2.4" />
-        <PackageReference Include="Avalonia.Fonts.Inter" Version="11.2.4" />
+        <PackageReference Include="Avalonia" Version="11.2.5" />
+        <PackageReference Include="Avalonia.Desktop" Version="11.2.5" />
+        <PackageReference Include="Avalonia.Themes.Fluent" Version="11.2.5" />
+        <PackageReference Include="Avalonia.Fonts.Inter" Version="11.2.5" />
         <!--Condition below is needed to remove Avalonia.Diagnostics package from build output in Release configuration.-->
-        <PackageReference Condition="'$(Configuration)' == 'Debug'" Include="Avalonia.Diagnostics" Version="11.2.4" />
-        <PackageReference Include="Avalonia.Xaml.Interactions" Version="11.2.0.9" />
+        <PackageReference Condition="'$(Configuration)' == 'Debug'" Include="Avalonia.Diagnostics" Version="11.2.5" />
+        <PackageReference Include="Avalonia.Xaml.Interactions" Version="11.2.0.14" />
         <PackageReference Include="CommunityToolkit.Mvvm" Version="8.4.0" />
     </ItemGroup>
 </Project>

ViewModels/MainWindowViewModel.cs

@@ -84,7 +84,8 @@ public class MainWindowViewModel : ViewModelBase
     private void OnCanvasPointerPressed(PointerPressedEventArgs? e)
     {
         if (e == null) return;
-        
+        if(UndoDrawingPoints.Count > 0) UndoDrawingPoints.Clear();
+
         IsDrawing = true;
         DrawingPoints.Add(new DrawingPoints(Brush, BrushThickness));
         DrawingPoint = DrawingPoints[^1];
@@ -111,4 +112,26 @@ public class MainWindowViewModel : ViewModelBase
     {
         IsDrawing = false;
     }
+
+    public void GlobalKeyUpHandler(KeyEventArgs e)
+    {
+        if (e.KeyModifiers != KeyModifiers.Control) return;
+        switch (e.Key)
+        {
+            case Key.Z:
+                if (DrawingPoints.Count > 0)
+                {
+                    UndoDrawingPoints.Add(DrawingPoints[^1]);
+                    DrawingPoints.Remove(DrawingPoints[^1]);
+                }
+                break;
+            case Key.Y:
+                if (UndoDrawingPoints.Count > 0)
+                {
+                    DrawingPoints.Add(UndoDrawingPoints[^1]);
+                    UndoDrawingPoints.Remove(UndoDrawingPoints[^1]);
+                }
+                break;
+        }
+    }
 }

ViewModels/ViewModelBase.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using System.ComponentModel.DataAnnotations;
 using System.IO;
@@ -27,7 +28,8 @@ public class ViewModelBase : ObservableObject
     public IRelayCommand<PointerReleasedEventArgs>? CanvasPointerReleasedCommand { get; set; }
     public ObservableCollection<DrawingPoints> DrawingPoints { get; set; } = new();
     public DrawingPoints? DrawingPoint { get; set; }
-    
+    protected List<DrawingPoints> UndoDrawingPoints = new();
+
     protected bool IsDrawing { get; set; }
 
     private string _selectedColor = "Black";

Views/MainWindow.axaml

@@ -36,10 +36,10 @@
     </Design.DataContext>
 
     <Panel Background="Transparent">
-        <SplitView Background="Transparent" IsPaneOpen="{Binding IsSplitOpen, Mode=TwoWay}" DisplayMode="Overlay" OpenPaneLength="250" ClipToBounds="False">
+        <SplitView Background="Transparent" IsPaneOpen="{Binding IsSplitOpen, Mode=TwoWay}" DisplayMode="Overlay" OpenPaneLength="250" ClipToBounds="False" PaneBackground="Transparent">
             <SplitView.Pane>
-                <Border Background="Transparent" BorderBrush="Gray" BorderThickness="0" CornerRadius="0, 12.5,12.5,0" >
-                    <Grid Background="#66ffffff">
+                <Border Background="#d4d4fc" BorderBrush="Gray" BorderThickness="1" CornerRadius="0, 12.5,12.5,0">
+                    <Grid Background="#d4d4fc" Margin="5"> <!-- Background of left panel opened -->
                         <Grid Background="Transparent">
                             <Grid.RowDefinitions>
                                 <RowDefinition Height="50*"></RowDefinition>
@@ -133,6 +133,7 @@
             </Grid>
         </SplitView>
         <!-- left Info bar -->
+
         <StackPanel Width="30" HorizontalAlignment="Left" IsVisible="{Binding !IsSplitOpen}" Background="#d4d4fc">
             <!-- Menu-Opener -->
             <Button Content="≡"

Views/MainWindow.axaml.cs

@@ -19,6 +19,16 @@ public partial class MainWindow : Window
         DataContext = new MainWindowViewModel();
         Topmost = true;
         Topmost = false;
+
+        this.KeyUp += OnKeyUp;
+    }
+
+    private void OnKeyUp(object? sender, KeyEventArgs e)
+    {
+        if (DataContext is MainWindowViewModel vm)
+        {
+            vm.GlobalKeyUpHandler(e);
+        }
     }
 
     // MVVM like implementations burst the bounds -> implemented the old school way