Made minor changes in behavior

ViewModels/ViewModelBase.cs

@@ -1,4 +1,5 @@
 using System.Collections.ObjectModel;
+using System.ComponentModel.DataAnnotations;
 using Avalonia.Input;
 using Avalonia.Media;
 using CommunityToolkit.Mvvm.ComponentModel;
@@ -9,6 +10,9 @@ namespace SimpleDraw.ViewModels;
 
 public class ViewModelBase : ObservableObject
 {
+    public int WindowWidth { get; set; } = 1200;
+    public int WindowHeight { get; set; } = 800;
+    
     public ObservableCollection<ColorPickerButton>? ColorPalette { get; set; } 
     public IRelayCommand<PointerPressedEventArgs>? CanvasPointerPressedCommand { get; set; }
     public IRelayCommand<PointerEventArgs>? CanvasPointerMovedCommand { get; set; }
@@ -26,7 +30,7 @@ public class ViewModelBase : ObservableObject
         get => _brush;
         set => SetProperty(ref _brush, value);
     }
-
+    
     public double BrushThickness
     {
         get => _brushThickness;

Views/MainWindow.axaml

@@ -9,23 +9,36 @@
         xmlns:i="using:Avalonia.Xaml.Interactivity"
         xmlns:behaviors="using:Avalonia.Xaml.Interactions.Core"
         xmlns:componentModel="clr-namespace:CommunityToolkit.Mvvm.ComponentModel;assembly=CommunityToolkit.Mvvm"
+        xmlns:system="clr-namespace:System;assembly=System.Runtime"
         x:DataType="vm:MainWindowViewModel"
         Icon="/Assets/avalonia-logo.ico"
-        Title="SimpleDraw">
-
+        Title="SimpleDraw"
+        Width="{Binding WindowWidth}"
+        Height="{Binding WindowHeight}"
+        MinWidth="400"
+        MinHeight="300"
+        WindowStartupLocation="CenterScreen"
+        >
+    <Window.Resources>
+        <system:String x:Key="BrushSizeFormat">{0:0.#####}</system:String>
+    </Window.Resources>
+    
     <Design.DataContext>
         <!-- This only sets the DataContext for the previewer in an IDE,
              to set the actual DataContext for runtime, set the DataContext property in code (look at App.axaml.cs) -->
         <vm:MainWindowViewModel/>
     </Design.DataContext>
     
-    <Panel>
-        <Menu>
-            <MenuItem>
-                File
+    <DockPanel>
+        <Menu DockPanel.Dock="Top">
+            <MenuItem Header="_File">
+                <MenuItem Header="_Open..."/>
+                <Separator/>
+                <MenuItem Header="_Exit"/>
             </MenuItem>
-            <MenuItem>
-                Edit
+            <MenuItem Header="_Edit">
+                <MenuItem Header="Copy"/>
+                <MenuItem Header="Paste"/>
             </MenuItem>
         </Menu>
         <Grid Background="Gray">
@@ -33,11 +46,7 @@
                 <ColumnDefinition Width="105"></ColumnDefinition>
                 <ColumnDefinition Width="1*" MinWidth="300"></ColumnDefinition>
             </Grid.ColumnDefinitions>
-            <Grid.RowDefinitions>
-                <RowDefinition Height="25"></RowDefinition>
-                <RowDefinition Height="1*" MinHeight="300"></RowDefinition>
-            </Grid.RowDefinitions>
-            <Grid Grid.Row="1" Grid.Column="0" Background="LightGray">
+            <Grid Grid.Column="0" Background="LightGray">
                 <Grid.RowDefinitions>
                     <RowDefinition Height="50*"></RowDefinition>
                     <RowDefinition Height="50*"></RowDefinition>
@@ -66,10 +75,14 @@
                             </DataTemplate>
                         </ItemsControl.ItemTemplate>
                     </ItemsControl>
-                    <Slider Margin="5" Value="{Binding BrushThickness}" Maximum="50" Minimum="0.5"></Slider>
+                    <TextBox HorizontalAlignment="Left" TextAlignment="Left" Margin="5,5,5,0" IsHitTestVisible="False" IsReadOnly="True" BorderThickness="0" Background="Transparent">
+                        Brush Size:
+                    </TextBox>
+                    <TextBox Text="{Binding BrushThickness, Mode=TwoWay}" Margin="5,0" HorizontalAlignment="Stretch" TextAlignment="Left" BorderThickness="2" Background="Transparent"></TextBox>
+                    <Slider Margin="5, 0" Value="{Binding BrushThickness}" Maximum="50" Minimum="0.5"></Slider>
                 </StackPanel>
             </Grid>
-            <Canvas Grid.Row="1" Grid.Column="1" Background="White">
+            <Canvas Grid.Column="1" Background="White" HorizontalAlignment="Stretch" VerticalAlignment="Stretch">
                 <i:Interaction.Behaviors>
                     <behaviors:EventTriggerBehavior EventName="PointerPressed">
                         <behaviors:InvokeCommandAction 
@@ -91,7 +104,7 @@
                 <ItemsControl ItemsSource="{Binding DrawingPoints}">
                     <ItemsControl.ItemsPanel>
                         <ItemsPanelTemplate>
-                            <Panel/>
+                            <Panel HorizontalAlignment="Stretch" VerticalAlignment="Stretch" MinWidth="{Binding WindowWidth}" MinHeight="{Binding WindowHeight}"/>
                         </ItemsPanelTemplate>
                     </ItemsControl.ItemsPanel>
                     <ItemsControl.ItemTemplate>
@@ -106,6 +119,5 @@
                 </ItemsControl>
             </Canvas>
         </Grid>
-    </Panel>
-
+    </DockPanel>
 </Window>

Views/MainWindow.axaml.cs

@@ -1,4 +1,5 @@
 using Avalonia.Controls;
+using Avalonia.Input;
 using SimpleDraw.ViewModels;
 
 namespace SimpleDraw.Views;
@@ -9,5 +10,7 @@ public partial class MainWindow : Window
     {
         InitializeComponent();
         DataContext = new MainWindowViewModel();
+        Topmost = true;
+        Topmost = false;
     }
 }