Initial better gui implemented.

UX and information still missing alot

XSDVisualiser.Desktop/Converters/CardinalityToLabelConverter.cs

@@ -0,0 +1,24 @@
+using System;
+using System.Globalization;
+using Avalonia.Data.Converters;
+using XSDVisualiser.Models;
+
+namespace XSDVisualiser.Desktop.Converters
+{
+    public class CardinalityToLabelConverter : IValueConverter
+    {
+        public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
+        {
+            if (value is Occurs occ)
+            {
+                var min = occ.Min;
+                var max = occ.MaxIsUnbounded ? "*" : occ.Max.ToString(culture);
+                return $"[{min}..{max}]";
+            }
+            return null;
+        }
+
+        public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
+            => throw new NotSupportedException();
+    }
+}

XSDVisualiser.Desktop/Converters/OptionalToBorderBrushConverter.cs

@@ -0,0 +1,27 @@
+using System;
+using System.Globalization;
+using Avalonia.Data.Converters;
+using Avalonia.Media;
+using XSDVisualiser.Models;
+
+namespace XSDVisualiser.Desktop.Converters
+{
+    public class OptionalToBorderBrushConverter : IValueConverter
+    {
+        private static readonly IBrush RequiredBrush = new SolidColorBrush(Color.FromRgb(0x33, 0x99, 0x33));
+        private static readonly IBrush OptionalBrush = new SolidColorBrush(Color.FromRgb(0xCC, 0x66, 0x33));
+
+        public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
+        {
+            if (value is Occurs occ)
+            {
+                // Optional if minOccurs == 0
+                return occ.Min == 0 ? OptionalBrush : RequiredBrush;
+            }
+            return RequiredBrush;
+        }
+
+        public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
+            => throw new NotSupportedException();
+    }
+}

XSDVisualiser.Desktop/Converters/OptionalToThicknessConverter.cs

@@ -0,0 +1,27 @@
+using System;
+using System.Globalization;
+using Avalonia;
+using Avalonia.Data.Converters;
+using XSDVisualiser.Models;
+
+namespace XSDVisualiser.Desktop.Converters
+{
+    public class OptionalToThicknessConverter : IValueConverter
+    {
+        private static readonly Thickness Required = new Thickness(2);
+        private static readonly Thickness Optional = new Thickness(2);
+
+        public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
+        {
+            if (value is Occurs occ)
+            {
+                // We could vary thickness; for now same thickness regardless, reserved for future styling.
+                return occ.Min == 0 ? Optional : Required;
+            }
+            return Required;
+        }
+
+        public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
+            => throw new NotSupportedException();
+    }
+}

XSDVisualiser.Desktop/MainWindow.axaml

@@ -1,10 +1,59 @@
 <Window xmlns="https://github.com/avaloniaui"
         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+        xmlns:m="clr-namespace:XSDVisualiser.Models;assembly=XSDVisualiser.Core"
+        xmlns:conv="clr-namespace:XSDVisualiser.Desktop.Converters"
         x:Class="XSDVisualiser.Desktop.MainWindow"
-        Title="XSD Visualiser" Width="1000" Height="700">
+        x:DataType="m:SchemaModel"
-    <StackPanel Margin="12" Spacing="8">
+        Title="XSD Visualiser" Width="1100" Height="800">
+    <Window.Resources>
+        <conv:CardinalityToLabelConverter x:Key="CardinalityToLabel"/>
+        <conv:OptionalToBorderBrushConverter x:Key="OptionalToBrush"/>
+        <conv:OptionalToThicknessConverter x:Key="OptionalToThickness"/>
+    </Window.Resources>
+
+    <Grid RowDefinitions="Auto,*" Margin="12">
+        <StackPanel Orientation="Horizontal" Spacing="8">
             <TextBlock Text="XSD Visualiser (Avalonia)" FontSize="18"/>
-        <Button Content="Open XSD and parse" x:Name="OpenBtn" Width="200"/>
+            <Button Content="Open XSD and parse" x:Name="OpenBtn" Width="200" Margin="12,0,0,0"/>
-        <TextBox x:Name="Output" AcceptsReturn="True" Height="600" TextWrapping="Wrap" FontFamily="Consolas"/>
         </StackPanel>
+
+        <ScrollViewer Grid.Row="1">
+            <TreeView x:Name="SchemaTree" ItemsSource="{Binding RootElements}">
+                <TreeView.DataTemplates>
+                    <TreeDataTemplate DataType="{x:Type m:SchemaNode}" ItemsSource="{Binding Children}">
+                        <StackPanel>
+                            <!-- Connector line from parent to this node (hidden for roots where ContentModel is null) -->
+                            <Grid Margin="0,6,0,2" IsVisible="{Binding ContentModel, Converter={x:Static ObjectConverters.IsNotNull}}">
+                                <Grid.ColumnDefinitions>
+                                    <ColumnDefinition Width="16"/>
+                                    <ColumnDefinition Width="*"/>
+                                </Grid.ColumnDefinitions>
+                                <!-- leading small elbow -->
+                                <Rectangle Grid.Column="0" Width="16" Height="2" Fill="#888" VerticalAlignment="Center"/>
+                                <Grid Grid.Column="1">
+                                    <Rectangle Height="2" Fill="#888" VerticalAlignment="Center"/>
+                                    <TextBlock Text="{Binding Cardinality, Converter={StaticResource CardinalityToLabel}}"
+                                               Background="#F0F0F0" Padding="4,0"
+                                               HorizontalAlignment="Center"/>
+                                </Grid>
+                            </Grid>
+
+                            <!-- Node content -->
+                            <Border CornerRadius="4"
+                                    BorderBrush="{Binding Cardinality, Converter={StaticResource OptionalToBrush}}"
+                                    BorderThickness="{Binding Cardinality, Converter={StaticResource OptionalToThickness}}"
+                                    Padding="8" Margin="0,0,0,4">
+                                <StackPanel Orientation="Horizontal" Spacing="6">
+                                    <TextBlock Text="{Binding Name}" FontWeight="Bold"/>
+                                    <TextBlock Text="{Binding TypeName}" Foreground="#555"/>
+                                    <TextBlock Text="{Binding BuiltInType}" Foreground="#777"/>
+                                    <TextBlock Text="{Binding ContentModel}" Foreground="#999"/>
+                                </StackPanel>
+                            </Border>
+                        </StackPanel>
+                    </TreeDataTemplate>
+                </TreeView.DataTemplates>
+            </TreeView>
+        </ScrollViewer>
+    </Grid>
 </Window>

XSDVisualiser.Desktop/MainWindow.axaml.cs

@@ -1,24 +1,21 @@
 using System;
-using System.Linq;
 using System.Threading.Tasks;
 using Avalonia.Controls;
 using Avalonia.Interactivity;
 using Avalonia.Threading;
+using XSDVisualiser.Models;
 using XSDVisualiser.Parsing;
-using XSDVisualiser.Utils;
 
 namespace XSDVisualiser.Desktop
 {
     public partial class MainWindow : Window
     {
         private Button _openBtn = null!;
-        private TextBox _output = null!;
 
         public MainWindow()
         {
             InitializeComponent();
             _openBtn = this.FindControl<Button>("OpenBtn");
-            _output = this.FindControl<TextBox>("Output");
             _openBtn.Click += OpenBtn_Click;
         }
 
@@ -45,12 +42,11 @@ namespace XSDVisualiser.Desktop
                 {
                     var parser = new XsdSchemaParser();
                     var model = parser.Parse(path);
-                    var text = Serialization.ToJson(model);
+                    Dispatcher.UIThread.Post(() => DataContext = model);
-                    Dispatcher.UIThread.Post(() => _output.Text = text);
                 }
                 catch (Exception ex)
                 {
-                    Dispatcher.UIThread.Post(() => _output.Text = ex.ToString());
+                    Dispatcher.UIThread.Post(() => DataContext = new SchemaModel { TargetNamespace = ex.Message });
                 }
             });
         }