Implemented JSON syntax checking

Implemented (re)storing of main window position

PettingZoo.Core/Settings/IUISettingsRepository.cs

@@ -0,0 +1,30 @@
+using System.Threading.Tasks;
+
+namespace PettingZoo.Core.Settings
+{
+    public interface IUISettingsRepository
+    {
+        Task<MainWindowPositionSettings?> GetMainWindowPosition();
+        Task StoreMainWindowPosition(MainWindowPositionSettings settings);
+    }
+
+
+    public class MainWindowPositionSettings
+    {
+        public int Top { get; }
+        public int Left { get; }
+        public int Width { get; }
+        public int Height { get; }
+        public bool Maximized { get; }
+
+
+        public MainWindowPositionSettings(int top, int left, int width, int height, bool maximized)
+        {
+            Top = top;
+            Left = left;
+            Width = width;
+            Height = height;
+            Maximized = maximized;
+        }
+    }
+}

PettingZoo.Settings.LiteDB/BaseLiteDBRepository.cs

@@ -7,6 +7,11 @@ namespace PettingZoo.Settings.LiteDB
     {
         private readonly string databaseFilename;
 
+        protected static readonly BsonMapper Mapper = new()
+        {
+            EmptyStringToNull = false
+        };
+
 
         public BaseLiteDBRepository(string databaseName)
         {
@@ -24,10 +29,7 @@ namespace PettingZoo.Settings.LiteDB
 
         protected ILiteDatabaseAsync GetDatabase()
         {
-            return new LiteDatabaseAsync(databaseFilename, new BsonMapper
+            return new LiteDatabaseAsync(databaseFilename, Mapper);
-            {
-                EmptyStringToNull = false
-            });
         }
     }
 }

PettingZoo.Settings.LiteDB/LiteDBUISettingsRepository.cs

@@ -0,0 +1,84 @@
+using PettingZoo.Core.Settings;
+
+namespace PettingZoo.Settings.LiteDB
+{
+    public class LiteDBUISettingsRepository : BaseLiteDBRepository, IUISettingsRepository
+    {
+        private const string CollectionSettings = "settings";
+
+        
+        public LiteDBUISettingsRepository() : base(@"uiSettings")
+        {
+        }
+
+
+        public async Task<MainWindowPositionSettings?> GetMainWindowPosition()
+        {
+            using var database = GetDatabase();
+            var collection = database.GetCollection(CollectionSettings);
+
+            var settings = await collection.FindByIdAsync(MainWindowPositionSettingsRecord.SettingsKey);
+            if (settings == null)
+                return null;
+
+            var position = Mapper.ToObject<MainWindowPositionSettingsRecord>(settings);
+            return new MainWindowPositionSettings(
+                position.Top,
+                position.Left,
+                position.Width,
+                position.Height,
+                position.Maximized);
+        }
+
+
+        public async Task StoreMainWindowPosition(MainWindowPositionSettings settings)
+        {
+            using var database = GetDatabase();
+            var collection = database.GetCollection(CollectionSettings);
+
+            await collection.UpsertAsync(
+                Mapper.ToDocument(new MainWindowPositionSettingsRecord
+                {
+                    Top = settings.Top,
+                    Left = settings.Left,
+                    Width = settings.Width,
+                    Height = settings.Height,
+                    Maximized = settings.Maximized
+                }));
+        }
+
+
+
+        // ReSharper disable MemberCanBePrivate.Local - for LiteDB
+        // ReSharper disable PropertyCanBeMadeInitOnly.Local
+        private class BaseSettingsRecord
+        {
+            // ReSharper disable once UnusedAutoPropertyAccessor.Local
+            public Guid Id { get; }
+
+            protected BaseSettingsRecord(Guid id)
+            {
+                Id = id;
+            }
+        }
+
+
+        private class MainWindowPositionSettingsRecord : BaseSettingsRecord
+        {
+            public static readonly Guid SettingsKey = new("fc71cf99-0744-4f5d-ada8-6a78d1df7b62");
+
+
+            public int Top { get; set; }
+            public int Left { get; set; }
+            public int Width { get; set; }
+            public int Height { get; set; }
+            public bool Maximized { get; set; }
+
+            public MainWindowPositionSettingsRecord() : base(SettingsKey)
+            {
+            }
+        }
+        // ReSharper restore PropertyCanBeMadeInitOnly.Local
+        // ReSharper restore MemberCanBePrivate.Local
+    }
+}

PettingZoo.sln.DotSettings

@@ -1,5 +1,7 @@
 <wpf:ResourceDictionary xml:space="preserve" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:s="clr-namespace:System;assembly=mscorlib" xmlns:ss="urn:shemas-jetbrains-com:settings-storage-xaml" xmlns:wpf="http://schemas.microsoft.com/winfx/2006/xaml/presentation">
 	<s:Boolean x:Key="/Default/CodeInspection/CodeAnnotations/NamespacesWithAnnotations/=PettingZoo_002EAnnotations/@EntryIndexedValue">True</s:Boolean>
 	<s:String x:Key="/Default/CodeStyle/Naming/CSharpNaming/Abbreviations/=DB/@EntryIndexedValue">DB</s:String>
+	<s:String x:Key="/Default/CodeStyle/Naming/CSharpNaming/Abbreviations/=DBUI/@EntryIndexedValue">DBUI</s:String>
+	<s:String x:Key="/Default/CodeStyle/Naming/CSharpNaming/Abbreviations/=UI/@EntryIndexedValue">UI</s:String>
 	<s:String x:Key="/Default/CodeStyle/Naming/CSharpNaming/Abbreviations/=MQ/@EntryIndexedValue">MQ</s:String>
 	<s:String x:Key="/Default/CodeStyle/Naming/CSharpNaming/Abbreviations/=WPF/@EntryIndexedValue">WPF</s:String></wpf:ResourceDictionary>

PettingZoo/App.xaml.cs

@@ -1,10 +1,83 @@
-using System.Windows;
+using System;
+using System.Drawing;
+using System.Linq;
+using System.Threading.Tasks;
+using System.Windows;
 using System.Windows.Threading;
+using PettingZoo.Core.Settings;
+using PettingZoo.UI.Main;
+using SimpleInjector;
+using Point = System.Windows.Point;
 
 namespace PettingZoo
 {
     public partial class App
     {
+        private readonly Container container;
+
+
+        public App()
+        {
+            throw new InvalidOperationException("Default main should not be used");
+        }
+
+
+        public App(Container container)
+        {
+            this.container = container;
+        }
+
+
+        protected override async void OnStartup(StartupEventArgs e)
+        {
+            var uitSettingsRepository = container.GetInstance<IUISettingsRepository>();
+            var position = await uitSettingsRepository.GetMainWindowPosition();
+
+            var mainWindow = container.GetInstance<MainWindow>();
+
+            if (position != null)
+            {
+                var positionBounds = new Rect(
+                    new Point(position.Left, position.Top), 
+                    new Point(position.Left + position.Width, position.Top + position.Height));
+
+                if (InScreenBounds(positionBounds))
+                {
+                    mainWindow.WindowStartupLocation = WindowStartupLocation.Manual;
+                    mainWindow.Top = positionBounds.Top;
+                    mainWindow.Left = positionBounds.Left;
+                    mainWindow.Width = positionBounds.Width;
+                    mainWindow.Height = positionBounds.Height;
+                }
+
+                mainWindow.WindowState = position.Maximized ? WindowState.Maximized : WindowState.Normal;
+            }
+
+            mainWindow.Closing += (_, _) =>
+            {
+                var newPosition = new MainWindowPositionSettings(
+                    (int)mainWindow.RestoreBounds.Top,
+                    (int)mainWindow.RestoreBounds.Left,
+                    (int)mainWindow.RestoreBounds.Width,
+                    (int)mainWindow.RestoreBounds.Height,
+                    mainWindow.WasMaximized);
+
+                Task.Run(() => uitSettingsRepository.StoreMainWindowPosition(newPosition));
+            };
+
+            mainWindow.Show();
+        }
+
+
+        private static bool InScreenBounds(Rect bounds)
+        {
+            var boundsRectangle = new Rectangle((int)bounds.Left, (int)bounds.Top, (int)bounds.Width, (int)bounds.Height);
+
+            // There doesn't appear to be any way to get this information other than from System.Windows.From/PInvoke at the time of writing
+            return System.Windows.Forms.Screen.AllScreens.Any(screen => screen.Bounds.IntersectsWith(boundsRectangle));
+        }
+
+
         private void App_OnDispatcherUnhandledException(object sender, DispatcherUnhandledExceptionEventArgs e)
         {
             _ = MessageBox.Show($"Unhandled exception: {e.Exception.Message}", "Petting Zoo - Exception", MessageBoxButton.OK, MessageBoxImage.Error);

PettingZoo/Images/Error.svg

@@ -0,0 +1,69 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<!-- Generator: Adobe Illustrator 18.0.0, SVG Export Plug-In . SVG Version: 6.00 Build 0)  -->
+
+<svg
+   version="1.1"
+   id="Capa_1"
+   x="0px"
+   y="0px"
+   viewBox="0 0 24 24"
+   xml:space="preserve"
+   sodipodi:docname="Error.svg"
+   width="24"
+   height="24"
+   inkscape:version="1.1.1 (3bf5ae0d25, 2021-09-20)"
+   xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
+   xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
+   xmlns="http://www.w3.org/2000/svg"
+   xmlns:svg="http://www.w3.org/2000/svg"><defs
+   id="defs130">
+		
+		
+	</defs><sodipodi:namedview
+   id="namedview128"
+   pagecolor="#ffffff"
+   bordercolor="#666666"
+   borderopacity="1.0"
+   inkscape:pageshadow="2"
+   inkscape:pageopacity="0.0"
+   inkscape:pagecheckerboard="0"
+   showgrid="false"
+   inkscape:zoom="14.344828"
+   inkscape:cx="-14.395433"
+   inkscape:cy="-2.9627404"
+   inkscape:window-width="1920"
+   inkscape:window-height="1017"
+   inkscape:window-x="1912"
+   inkscape:window-y="-8"
+   inkscape:window-maximized="1"
+   inkscape:current-layer="Capa_1" />
+<g
+   id="g95"
+   transform="translate(-34,-32)">
+	
+	<circle
+   style="fill:#ed7161"
+   cx="46"
+   cy="44"
+   r="12"
+   id="circle89" /><path
+   style="fill:#ffffff"
+   d="m 47.414,44 3.536,-3.536 c 0.391,-0.391 0.391,-1.023 0,-1.414 -0.391,-0.391 -1.023,-0.391 -1.414,0 l -3.536,3.536 -3.536,-3.536 c -0.391,-0.391 -1.023,-0.391 -1.414,0 -0.391,0.391 -0.391,1.023 0,1.414 l 3.536,3.536 -3.536,3.536 c -0.391,0.391 -0.391,1.023 0,1.414 0.195,0.195 0.451,0.293 0.707,0.293 0.256,0 0.512,-0.098 0.707,-0.293 l 3.536,-3.536 3.536,3.536 c 0.195,0.195 0.451,0.293 0.707,0.293 0.256,0 0.512,-0.098 0.707,-0.293 0.391,-0.391 0.391,-1.023 0,-1.414 z"
+   id="path91" />
+</g>
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+</svg>

PettingZoo/Images/Ok.svg

@@ -0,0 +1,54 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<!-- Generator: Adobe Illustrator 18.0.0, SVG Export Plug-In . SVG Version: 6.00 Build 0)  -->
+
+<svg
+   version="1.1"
+   id="Capa_1"
+   x="0px"
+   y="0px"
+   viewBox="0 0 24 24"
+   xml:space="preserve"
+   sodipodi:docname="Ok.svg"
+   width="24"
+   height="24"
+   inkscape:version="1.1.1 (3bf5ae0d25, 2021-09-20)"
+   xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
+   xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
+   xmlns="http://www.w3.org/2000/svg"
+   xmlns:svg="http://www.w3.org/2000/svg"><defs
+   id="defs13" /><sodipodi:namedview
+   id="namedview11"
+   pagecolor="#ffffff"
+   bordercolor="#666666"
+   borderopacity="1.0"
+   inkscape:pageshadow="2"
+   inkscape:pageopacity="0.0"
+   inkscape:pagecheckerboard="0"
+   showgrid="false"
+   inkscape:zoom="7.1724138"
+   inkscape:cx="-11.362981"
+   inkscape:cy="7.1802885"
+   inkscape:window-width="1920"
+   inkscape:window-height="1017"
+   inkscape:window-x="1912"
+   inkscape:window-y="-8"
+   inkscape:window-maximized="1"
+   inkscape:current-layer="Capa_1" />
+<g
+   id="g8"
+   transform="translate(-34,-32)">
+	<g
+   id="g6">
+		<circle
+   style="fill:#26b999"
+   cx="46"
+   cy="44"
+   r="12"
+   id="circle2" />
+		<path
+   style="fill:#ffffff"
+   d="m 52.571,38.179 c -0.455,-0.316 -1.077,-0.204 -1.392,0.25 l -5.596,8.04 -3.949,-3.242 c -0.426,-0.351 -1.057,-0.288 -1.407,0.139 -0.351,0.427 -0.289,1.057 0.139,1.407 l 4.786,3.929 c 0.18,0.147 0.404,0.227 0.634,0.227 0.045,0 0.091,-0.003 0.137,-0.009 0.276,-0.039 0.524,-0.19 0.684,-0.419 l 6.214,-8.929 c 0.315,-0.454 0.203,-1.077 -0.25,-1.393 z"
+   id="path4" />
+	</g>
+</g>
+</svg>

PettingZoo/PettingZoo.csproj

@@ -5,6 +5,7 @@
     <TargetFramework>net6.0-windows</TargetFramework>
     <Version>0.1</Version>
     <UseWPF>true</UseWPF>
+	<UseWindowsForms>true</UseWindowsForms>
     <Authors>Mark van Renswoude</Authors>
     <Product>Petting Zoo</Product>
     <Description>Petting Zoo - a live RabbitMQ message viewer</Description>
@@ -19,6 +20,8 @@
 
   <ItemGroup>
     <None Remove="Images\Dock.svg" />
+    <None Remove="Images\Error.svg" />
+    <None Remove="Images\Ok.svg" />
     <None Remove="Images\PublishSend.svg" />
     <None Remove="Images\Undock.svg" />
   </ItemGroup>
@@ -28,6 +31,8 @@
     <Resource Include="Images\Connect.svg" />
     <Resource Include="Images\Disconnect.svg" />
     <Resource Include="Images\Dock.svg" />
+    <Resource Include="Images\Error.svg" />
+    <Resource Include="Images\Ok.svg" />
     <Resource Include="Images\Publish.svg" />
     <Resource Include="Images\PublishSend.svg" />
     <Resource Include="Images\Subscribe.svg" />
@@ -35,8 +40,9 @@
 
   <ItemGroup>
     <PackageReference Include="Newtonsoft.Json" Version="13.0.1" />
-    <PackageReference Include="SharpVectors" Version="1.7.6" />
+    <PackageReference Include="SharpVectors" Version="1.7.7" />
     <PackageReference Include="SimpleInjector" Version="5.3.2" />
+    <PackageReference Include="System.Reactive" Version="5.0.0" />
   </ItemGroup>
 
   <ItemGroup>
@@ -75,6 +81,11 @@
       <DesignTime>True</DesignTime>
       <AutoGen>True</AutoGen>
     </Compile>
+    <Compile Update="UI\Tab\Publisher\PayloadEditorStrings.Designer.cs">
+      <DesignTime>True</DesignTime>
+      <AutoGen>True</AutoGen>
+      <DependentUpon>PayloadEditorStrings.resx</DependentUpon>
+    </Compile>
     <Compile Update="UI\Tab\Publisher\TapetiPublisherViewStrings.Designer.cs">
       <DependentUpon>TapetiPublisherViewStrings.resx</DependentUpon>
       <DesignTime>True</DesignTime>
@@ -126,6 +137,10 @@
       <LastGenOutput>SubscribeWindowStrings.Designer.cs</LastGenOutput>
       <Generator>PublicResXFileCodeGenerator</Generator>
     </EmbeddedResource>
+    <EmbeddedResource Update="UI\Tab\Publisher\PayloadEditorStrings.resx">
+      <Generator>ResXFileCodeGenerator</Generator>
+      <LastGenOutput>PayloadEditorStrings.Designer.cs</LastGenOutput>
+    </EmbeddedResource>
     <EmbeddedResource Update="UI\Tab\Publisher\TapetiPublisherViewStrings.resx">
       <LastGenOutput>TapetiPublisherViewStrings.Designer.cs</LastGenOutput>
       <Generator>PublicResXFileCodeGenerator</Generator>

PettingZoo/Program.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Globalization;
+using System.Threading.Tasks;
 using System.Windows;
 using System.Windows.Markup;
 using PettingZoo.Core.Connection;
@@ -38,6 +39,7 @@ namespace PettingZoo
             container.Register<IConnectionDialog, WindowConnectionDialog>();
             container.Register<ISubscribeDialog, WindowSubscribeDialog>();
             container.Register<IConnectionSettingsRepository, LiteDBConnectionSettingsRepository>();
+            container.Register<IUISettingsRepository, LiteDBUISettingsRepository>();
 
             container.Register<MainWindow>();
             
@@ -49,7 +51,7 @@ namespace PettingZoo
         {
             try
             {
-                var app = new App();
+                var app = new App(container);
                 app.InitializeComponent();
 
                 #if DEBUG
@@ -65,8 +67,7 @@ namespace PettingZoo
                 // All this is the reason we only perform verification in debug builds
                 #endif
                 
-                var mainWindow = container.GetInstance<MainWindow>();
+                app.Run();
-                _ = app.Run(mainWindow);
             }
             catch (Exception e)
             {

PettingZoo/TODO.md

@@ -1,6 +1,5 @@
 Must-have
 ---------
-- Option to not save password in profiles
 
 
 Should-have
@@ -11,5 +10,4 @@ Should-have
 
 Nice-to-have
 ------------
-- JSON validation
 - JSON syntax highlighting

PettingZoo/UI/DependencyObjectExtensions.cs

@@ -0,0 +1,29 @@
+using System;
+using System.ComponentModel;
+using System.Reactive.Disposables;
+using System.Reactive.Linq;
+using System.Windows;
+
+namespace PettingZoo.UI
+{
+    public static class DependencyObjectExtensions
+    {
+        public static IObservable<T> OnPropertyChanges<T>(this DependencyObject source, DependencyProperty property)
+        {
+            return Observable.Create<T>(o => 
+            {
+                var dpd = DependencyPropertyDescriptor.FromProperty(property, property.OwnerType);
+                if (dpd == null)
+                    o.OnError(new InvalidOperationException("Can not register change handler for this dependency property."));
+
+                void Handler(object? sender, EventArgs e)
+                {
+                    o.OnNext((T)source.GetValue(property));
+                }
+
+                dpd?.AddValueChanged(source, Handler);
+                return Disposable.Create(() => dpd?.RemoveValueChanged(source, Handler));
+            });
+        }
+    }
+}

PettingZoo/UI/EnumBooleanConverter.cs

@@ -0,0 +1,19 @@
+using System;
+using System.Globalization;
+using System.Windows.Data;
+
+namespace PettingZoo.UI
+{
+    public class EnumBooleanConverter : IValueConverter
+    {
+        public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
+        {
+            return value.Equals(parameter);
+        }
+
+        public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
+        {
+            return ((bool)value) ? parameter : Binding.DoNothing;
+        }
+    }
+}

PettingZoo/UI/Main/MainWindow.xaml.cs

@@ -18,6 +18,8 @@ namespace PettingZoo.UI.Main
     {
         private readonly MainWindowViewModel viewModel;
 
+        public bool WasMaximized;
+        
 
         public MainWindow(IConnectionFactory connectionFactory, IConnectionDialog connectionDialog, ISubscribeDialog subscribeDialog)
         {
@@ -28,6 +30,20 @@ namespace PettingZoo.UI.Main
             InitializeComponent();
 
             Dispatcher.ShutdownStarted += OnDispatcherShutDownStarted;
+
+
+            // If the WindowState is Minimized, we can't tell if it was maximized before. To properly store
+            // the last window position, keep track of it.
+            this.OnPropertyChanges<WindowState>(WindowStateProperty)
+                .Subscribe(newState =>
+                {
+                    WasMaximized = newState switch
+                    {
+                        WindowState.Maximized => true,
+                        WindowState.Normal => false,
+                        _ => WasMaximized
+                    };
+                });
         }
 
 

PettingZoo/UI/Tab/Publisher/PayloadEditorControl.xaml

@@ -0,0 +1,31 @@
+<UserControl x:Class="PettingZoo.UI.Tab.Publisher.PayloadEditorControl"
+             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
+             xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+             xmlns:publisher="clr-namespace:PettingZoo.UI.Tab.Publisher"
+             xmlns:ui="clr-namespace:PettingZoo.UI"
+             xmlns:svgc="http://sharpvectors.codeplex.com/svgc/"
+             mc:Ignorable="d" 
+             d:DesignHeight="450" d:DesignWidth="800"
+             Background="White">
+    <UserControl.Resources>
+        <ui:EnumBooleanConverter x:Key="EnumBooleanConverter" />
+    </UserControl.Resources>
+    <DockPanel x:Name="DataContextContainer" d:DataContext="{d:DesignInstance publisher:DesignTimePayloadEditorViewModel, IsDesignTimeCreatable=True}">
+        <StackPanel Orientation="Horizontal" DockPanel.Dock="Top" Visibility="{Binding ContentTypeVisibility}" Margin="0,0,0,8">
+            <RadioButton Content="JSON" Style="{StaticResource TypeSelection}" IsChecked="{Binding ContentTypeSelection, Converter={StaticResource EnumBooleanConverter}, ConverterParameter={x:Static publisher:PayloadEditorContentType.Json}}" />
+            <RadioButton Content="Plain text" Style="{StaticResource TypeSelection}"  IsChecked="{Binding ContentTypeSelection, Converter={StaticResource EnumBooleanConverter}, ConverterParameter={x:Static publisher:PayloadEditorContentType.Plain}}" />
+            <RadioButton Content="Other" Style="{StaticResource TypeSelection}"  IsChecked="{Binding ContentTypeSelection, Converter={StaticResource EnumBooleanConverter}, ConverterParameter={x:Static publisher:PayloadEditorContentType.Other}}" />
+            <TextBox Width="200" Text="{Binding ContentType, UpdateSourceTrigger=PropertyChanged}" />
+        </StackPanel>
+
+        <StackPanel Orientation="Horizontal" DockPanel.Dock="Bottom" Visibility="{Binding JsonValidationVisibility}" Margin="0,8,0,0">
+            <Image Source="{svgc:SvgImage Source=/Images/Ok.svg, AppName=PettingZoo}" Width="16" Height="16" Margin="4" Visibility="{Binding JsonValidationOk}" />
+            <Image Source="{svgc:SvgImage Source=/Images/Error.svg, AppName=PettingZoo}" Width="16" Height="16" Margin="4" Visibility="{Binding JsonValidationError}" />
+            <TextBlock Text="{Binding JsonValidationMessage}" Margin="4" />
+        </StackPanel>
+
+        <TextBox Text="{Binding Payload, UpdateSourceTrigger=PropertyChanged}" Style="{StaticResource Payload}" />
+    </DockPanel>
+</UserControl>

PettingZoo/UI/Tab/Publisher/PayloadEditorControl.xaml.cs

@@ -0,0 +1,141 @@
+using System;
+using System.Reactive.Linq;
+using System.Threading;
+using System.Windows;
+using System.Windows.Data;
+
+namespace PettingZoo.UI.Tab.Publisher
+{
+    /// <summary>
+    /// Interaction logic for PayloadEditorControl.xaml
+    /// </summary>
+    public partial class PayloadEditorControl
+    {
+        private readonly PayloadEditorViewModel viewModel = new();
+
+
+        public static readonly DependencyProperty ContentTypeProperty
+            = DependencyProperty.Register(
+                "ContentType",
+                typeof(string),
+                typeof(PayloadEditorControl),
+                new FrameworkPropertyMetadata("")
+                {
+                    BindsTwoWayByDefault = true,
+                    DefaultUpdateSourceTrigger = UpdateSourceTrigger.PropertyChanged
+                }
+            );
+
+        public string ContentType
+        {
+            get => viewModel.ContentType;
+            set
+            {
+                if (value == viewModel.ContentType)
+                    return;
+
+                SetValue(ContentTypeProperty, value);
+                viewModel.ContentType = value;
+            }
+        }
+
+
+        public static readonly DependencyProperty FixedJsonProperty
+            = DependencyProperty.Register(
+                "FixedJson",
+                typeof(bool),
+                typeof(PayloadEditorControl),
+                new PropertyMetadata(false)
+            );
+
+        public bool FixedJson
+        {
+            get => viewModel.FixedJson;
+            set
+            {
+                if (value == viewModel.FixedJson)
+                    return;
+
+                SetValue(FixedJsonProperty, value);
+                viewModel.FixedJson = value;
+            }
+        }
+
+        public static readonly DependencyProperty PayloadProperty
+            = DependencyProperty.Register(
+                "Payload",
+                typeof(string),
+                typeof(PayloadEditorControl),
+                new FrameworkPropertyMetadata("")
+                {
+                    BindsTwoWayByDefault = true,
+                    DefaultUpdateSourceTrigger = UpdateSourceTrigger.PropertyChanged
+                }
+            );
+
+        public string Payload
+        {
+            get => viewModel.Payload;
+            set
+            {
+                if (value == viewModel.Payload)
+                    return;
+
+                SetValue(PayloadProperty, value);
+                viewModel.Payload = value;
+            }
+        }
+
+        public PayloadEditorControl()
+        {
+            // Keep the exposed properties in sync with the ViewModel
+            this.OnPropertyChanges<string>(ContentTypeProperty)
+                .ObserveOn(SynchronizationContext.Current!)
+                .Subscribe(value =>
+                {
+                    viewModel.ContentType = value;
+                });
+
+
+            this.OnPropertyChanges<bool>(FixedJsonProperty)
+                .ObserveOn(SynchronizationContext.Current!)
+                .Subscribe(value =>
+                {
+                    viewModel.FixedJson = value;
+                });
+
+
+            this.OnPropertyChanges<string>(PayloadProperty)
+                .ObserveOn(SynchronizationContext.Current!)
+                .Subscribe(value =>
+                {
+                    viewModel.Payload = value;
+                });
+
+
+            viewModel.PropertyChanged += (_, args) =>
+            {
+                switch (args.PropertyName)
+                {
+                    case nameof(viewModel.ContentType):
+                        SetValue(ContentTypeProperty, viewModel.ContentType);
+                        break;
+
+                    case nameof(viewModel.FixedJson):
+                        SetValue(FixedJsonProperty, viewModel.FixedJson);
+                        break;
+
+                    case nameof(viewModel.Payload):
+                        SetValue(PayloadProperty, viewModel.Payload);
+                        break;
+                }
+            };
+
+            InitializeComponent();
+
+            // Setting the DataContext for the UserControl is a major PITA when binding the control's properties,
+            // so I've moved the ViewModel one level down to get the best of both worlds...
+            DataContextContainer.DataContext = viewModel;
+        }
+    }
+}

PettingZoo/UI/Tab/Publisher/PayloadEditorStrings.Designer.cs

@@ -0,0 +1,108 @@
+//------------------------------------------------------------------------------
+// <auto-generated>
+//     This code was generated by a tool.
+//     Runtime Version:4.0.30319.42000
+//
+//     Changes to this file may cause incorrect behavior and will be lost if
+//     the code is regenerated.
+// </auto-generated>
+//------------------------------------------------------------------------------
+
+namespace PettingZoo.UI.Tab.Publisher {
+    using System;
+    
+    
+    /// <summary>
+    ///   A strongly-typed resource class, for looking up localized strings, etc.
+    /// </summary>
+    // This class was auto-generated by the StronglyTypedResourceBuilder
+    // class via a tool like ResGen or Visual Studio.
+    // To add or remove a member, edit your .ResX file then rerun ResGen
+    // with the /str option, or rebuild your VS project.
+    [global::System.CodeDom.Compiler.GeneratedCodeAttribute("System.Resources.Tools.StronglyTypedResourceBuilder", "17.0.0.0")]
+    [global::System.Diagnostics.DebuggerNonUserCodeAttribute()]
+    [global::System.Runtime.CompilerServices.CompilerGeneratedAttribute()]
+    internal class PayloadEditorStrings {
+        
+        private static global::System.Resources.ResourceManager resourceMan;
+        
+        private static global::System.Globalization.CultureInfo resourceCulture;
+        
+        [global::System.Diagnostics.CodeAnalysis.SuppressMessageAttribute("Microsoft.Performance", "CA1811:AvoidUncalledPrivateCode")]
+        internal PayloadEditorStrings() {
+        }
+        
+        /// <summary>
+        ///   Returns the cached ResourceManager instance used by this class.
+        /// </summary>
+        [global::System.ComponentModel.EditorBrowsableAttribute(global::System.ComponentModel.EditorBrowsableState.Advanced)]
+        internal static global::System.Resources.ResourceManager ResourceManager {
+            get {
+                if (object.ReferenceEquals(resourceMan, null)) {
+                    global::System.Resources.ResourceManager temp = new global::System.Resources.ResourceManager("PettingZoo.UI.Tab.Publisher.PayloadEditorStrings", typeof(PayloadEditorStrings).Assembly);
+                    resourceMan = temp;
+                }
+                return resourceMan;
+            }
+        }
+        
+        /// <summary>
+        ///   Overrides the current thread's CurrentUICulture property for all
+        ///   resource lookups using this strongly typed resource class.
+        /// </summary>
+        [global::System.ComponentModel.EditorBrowsableAttribute(global::System.ComponentModel.EditorBrowsableState.Advanced)]
+        internal static global::System.Globalization.CultureInfo Culture {
+            get {
+                return resourceCulture;
+            }
+            set {
+                resourceCulture = value;
+            }
+        }
+        
+        /// <summary>
+        ///   Looks up a localized string similar to JSON.
+        /// </summary>
+        internal static string ContentTypeJson {
+            get {
+                return ResourceManager.GetString("ContentTypeJson", resourceCulture);
+            }
+        }
+        
+        /// <summary>
+        ///   Looks up a localized string similar to Other.
+        /// </summary>
+        internal static string ContentTypeOther {
+            get {
+                return ResourceManager.GetString("ContentTypeOther", resourceCulture);
+            }
+        }
+        
+        /// <summary>
+        ///   Looks up a localized string similar to Plain text.
+        /// </summary>
+        internal static string ContentTypePlain {
+            get {
+                return ResourceManager.GetString("ContentTypePlain", resourceCulture);
+            }
+        }
+        
+        /// <summary>
+        ///   Looks up a localized string similar to Invalid JSON: {0}.
+        /// </summary>
+        internal static string JsonValidationError {
+            get {
+                return ResourceManager.GetString("JsonValidationError", resourceCulture);
+            }
+        }
+        
+        /// <summary>
+        ///   Looks up a localized string similar to Valid JSON.
+        /// </summary>
+        internal static string JsonValidationOk {
+            get {
+                return ResourceManager.GetString("JsonValidationOk", resourceCulture);
+            }
+        }
+    }
+}

PettingZoo/UI/Tab/Publisher/PayloadEditorStrings.resx

@@ -0,0 +1,135 @@
+<?xml version="1.0" encoding="utf-8"?>
+<root>
+  <!-- 
+    Microsoft ResX Schema 
+    
+    Version 2.0
+    
+    The primary goals of this format is to allow a simple XML format 
+    that is mostly human readable. The generation and parsing of the 
+    various data types are done through the TypeConverter classes 
+    associated with the data types.
+    
+    Example:
+    
+    ... ado.net/XML headers & schema ...
+    <resheader name="resmimetype">text/microsoft-resx</resheader>
+    <resheader name="version">2.0</resheader>
+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>
+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>
+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>
+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>
+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">
+        <value>[base64 mime encoded serialized .NET Framework object]</value>
+    </data>
+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">
+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>
+        <comment>This is a comment</comment>
+    </data>
+                
+    There are any number of "resheader" rows that contain simple 
+    name/value pairs.
+    
+    Each data row contains a name, and value. The row also contains a 
+    type or mimetype. Type corresponds to a .NET class that support 
+    text/value conversion through the TypeConverter architecture. 
+    Classes that don't support this are serialized and stored with the 
+    mimetype set.
+    
+    The mimetype is used for serialized objects, and tells the 
+    ResXResourceReader how to depersist the object. This is currently not 
+    extensible. For a given mimetype the value must be set accordingly:
+    
+    Note - application/x-microsoft.net.object.binary.base64 is the format 
+    that the ResXResourceWriter will generate, however the reader can 
+    read any of the formats listed below.
+    
+    mimetype: application/x-microsoft.net.object.binary.base64
+    value   : The object must be serialized with 
+            : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter
+            : and then encoded with base64 encoding.
+    
+    mimetype: application/x-microsoft.net.object.soap.base64
+    value   : The object must be serialized with 
+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter
+            : and then encoded with base64 encoding.
+
+    mimetype: application/x-microsoft.net.object.bytearray.base64
+    value   : The object must be serialized into a byte array 
+            : using a System.ComponentModel.TypeConverter
+            : and then encoded with base64 encoding.
+    -->
+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />
+    <xsd:element name="root" msdata:IsDataSet="true">
+      <xsd:complexType>
+        <xsd:choice maxOccurs="unbounded">
+          <xsd:element name="metadata">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" />
+              </xsd:sequence>
+              <xsd:attribute name="name" use="required" type="xsd:string" />
+              <xsd:attribute name="type" type="xsd:string" />
+              <xsd:attribute name="mimetype" type="xsd:string" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="assembly">
+            <xsd:complexType>
+              <xsd:attribute name="alias" type="xsd:string" />
+              <xsd:attribute name="name" type="xsd:string" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="data">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />
+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />
+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="resheader">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" />
+            </xsd:complexType>
+          </xsd:element>
+        </xsd:choice>
+      </xsd:complexType>
+    </xsd:element>
+  </xsd:schema>
+  <resheader name="resmimetype">
+    <value>text/microsoft-resx</value>
+  </resheader>
+  <resheader name="version">
+    <value>2.0</value>
+  </resheader>
+  <resheader name="reader">
+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <resheader name="writer">
+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <data name="ContentTypeJson" xml:space="preserve">
+    <value>JSON</value>
+  </data>
+  <data name="ContentTypeOther" xml:space="preserve">
+    <value>Other</value>
+  </data>
+  <data name="ContentTypePlain" xml:space="preserve">
+    <value>Plain text</value>
+  </data>
+  <data name="JsonValidationError" xml:space="preserve">
+    <value>Invalid JSON: {0}</value>
+  </data>
+  <data name="JsonValidationOk" xml:space="preserve">
+    <value>Valid JSON</value>
+  </data>
+</root>

PettingZoo/UI/Tab/Publisher/PayloadEditorViewModel.cs

@@ -0,0 +1,154 @@
+using System;
+using System.ComponentModel;
+using System.Reactive.Linq;
+using System.Reactive.Subjects;
+using System.Windows;
+using Newtonsoft.Json.Linq;
+
+namespace PettingZoo.UI.Tab.Publisher
+{
+    public enum PayloadEditorContentType
+    {
+        Json,
+        Plain,
+        Other
+    };
+
+
+    public class PayloadEditorViewModel : BaseViewModel
+    {
+        private const string ContentTypeJson = "application/json";
+        private const string ContentTypePlain = "text/plain";
+
+        private string contentType = ContentTypeJson;
+        private PayloadEditorContentType contentTypeSelection = PayloadEditorContentType.Json;
+        private bool fixedJson;
+
+        private bool jsonValid = true;
+        private string jsonValidationMessage;
+
+        private string payload = "";
+
+
+        public string ContentType
+        {
+            get => ContentTypeSelection switch
+            {
+                PayloadEditorContentType.Json => ContentTypeJson,
+                PayloadEditorContentType.Plain => ContentTypePlain,
+                _ => contentType
+            };
+
+            set
+            {
+                if (!SetField(ref contentType, value))
+                    return;
+
+                ContentTypeSelection = value switch
+                {
+                    ContentTypeJson => PayloadEditorContentType.Json,
+                    ContentTypePlain => PayloadEditorContentType.Plain,
+                    _ => PayloadEditorContentType.Other
+                };
+            }
+        }
+
+
+        public PayloadEditorContentType ContentTypeSelection
+        {
+            get => contentTypeSelection;
+            set
+            {
+                if (!SetField(ref contentTypeSelection, value, otherPropertiesChanged: new [] { nameof(JsonValidationVisibility) }))
+                    return;
+
+                ContentType = ContentTypeSelection switch
+                {
+                    PayloadEditorContentType.Json => ContentTypeJson,
+                    PayloadEditorContentType.Plain => ContentTypePlain,
+                    _ => ContentType
+                };
+
+                ValidatePayload();
+            }
+        }
+
+
+        public bool FixedJson
+        {
+            get => fixedJson;
+            set => SetField(ref fixedJson, value);
+        }
+
+        public Visibility JsonValidationVisibility => ContentTypeSelection == PayloadEditorContentType.Json ? Visibility.Visible : Visibility.Collapsed;
+        public Visibility JsonValidationOk => JsonValid ? Visibility.Visible : Visibility.Collapsed;
+        public Visibility JsonValidationError => !JsonValid ? Visibility.Visible : Visibility.Collapsed;
+
+
+        public string JsonValidationMessage
+        {
+            get => jsonValidationMessage;
+            private set => SetField(ref jsonValidationMessage, value);
+        }
+
+
+        public bool JsonValid
+        {
+            get => jsonValid;
+            private set => SetField(ref jsonValid, value, otherPropertiesChanged: new[] { nameof(JsonValidationOk), nameof(JsonValidationError) });
+        }
+
+        public Visibility ContentTypeVisibility => FixedJson ? Visibility.Collapsed : Visibility.Visible;
+
+
+        public string Payload
+        {
+            get => payload;
+            set => SetField(ref payload, value);
+        }
+
+
+
+        public PayloadEditorViewModel()
+        {
+            jsonValidationMessage = PayloadEditorStrings.JsonValidationOk;
+
+            Observable.FromEventPattern<PropertyChangedEventHandler, PropertyChangedEventArgs>(
+                h => PropertyChanged += h,
+                h => PropertyChanged -= h)
+                .Where(e => e.EventArgs.PropertyName == nameof(Payload))
+                .Throttle(TimeSpan.FromMilliseconds(500))
+                .Subscribe(_ => ValidatePayload());
+        }
+
+
+        private void ValidatePayload()
+        {
+            if (ContentTypeSelection != PayloadEditorContentType.Json)
+            {
+                JsonValid = true;
+                JsonValidationMessage = PayloadEditorStrings.JsonValidationOk;
+                return;
+            }
+
+            try
+            {
+                if (!string.IsNullOrEmpty(Payload))
+                    JToken.Parse(Payload);
+
+                JsonValid = true;
+                JsonValidationMessage = PayloadEditorStrings.JsonValidationOk;
+            }
+            catch (Exception e)
+            {
+                JsonValid = false;
+                JsonValidationMessage = string.Format(PayloadEditorStrings.JsonValidationError, e.Message);
+            }
+        }
+    }
+
+
+    public class DesignTimePayloadEditorViewModel : PayloadEditorViewModel
+    {
+    }
+}

PettingZoo/UI/Tab/Publisher/RawPublisherView.xaml

@@ -29,7 +29,6 @@
             <RowDefinition Height="Auto" />
             <RowDefinition Height="Auto" />
             <RowDefinition Height="Auto" />
-            <RowDefinition Height="Auto" />
             <RowDefinition Height="16"/>
             <RowDefinition Height="Auto" />
             <RowDefinition Height="Auto" />
@@ -95,38 +94,35 @@
 
         <Label Grid.Row="2" Grid.Column="0" Content="{x:Static publisher:RawPublisherViewStrings.LabelProperties}" Style="{StaticResource SectionLabel}"/>
 
-        <Label Grid.Row="3" Grid.Column="0" Content="{x:Static publisher:RawPublisherViewStrings.LabelContentType}" />
+        <Label Grid.Row="3" Grid.Column="0" Content="{x:Static publisher:RawPublisherViewStrings.LabelCorrelationId}" />
-        <TextBox Grid.Row="3" Grid.Column="1" Text="{Binding ContentType, UpdateSourceTrigger=PropertyChanged}" />
+        <TextBox Grid.Row="3" Grid.Column="1" Text="{Binding CorrelationId, UpdateSourceTrigger=PropertyChanged}" />
 
-        <Label Grid.Row="4" Grid.Column="0" Content="{x:Static publisher:RawPublisherViewStrings.LabelCorrelationId}" />
+        <Label Grid.Row="4" Grid.Column="0" Content="{x:Static publisher:RawPublisherViewStrings.LabelAppId}" Visibility="{Binding PropertiesExpandedVisibility}" />
-        <TextBox Grid.Row="4" Grid.Column="1" Text="{Binding CorrelationId, UpdateSourceTrigger=PropertyChanged}" />
+        <TextBox Grid.Row="4" Grid.Column="1" Text="{Binding AppId, UpdateSourceTrigger=PropertyChanged}" Visibility="{Binding PropertiesExpandedVisibility}" />
 
-        <Label Grid.Row="5" Grid.Column="0" Content="{x:Static publisher:RawPublisherViewStrings.LabelAppId}" Visibility="{Binding PropertiesExpandedVisibility}" />
+        <Label Grid.Row="5" Grid.Column="0" Content="{x:Static publisher:RawPublisherViewStrings.LabelContentEncoding}" Visibility="{Binding PropertiesExpandedVisibility}" />
-        <TextBox Grid.Row="5" Grid.Column="1" Text="{Binding AppId, UpdateSourceTrigger=PropertyChanged}" Visibility="{Binding PropertiesExpandedVisibility}" />
+        <TextBox Grid.Row="5" Grid.Column="1" Text="{Binding ContentEncoding, UpdateSourceTrigger=PropertyChanged}" Visibility="{Binding PropertiesExpandedVisibility}" />
 
-        <Label Grid.Row="6" Grid.Column="0" Content="{x:Static publisher:RawPublisherViewStrings.LabelContentEncoding}" Visibility="{Binding PropertiesExpandedVisibility}" />
+        <Label Grid.Row="6" Grid.Column="0" Content="{x:Static publisher:RawPublisherViewStrings.LabelExpiration}" Visibility="{Binding PropertiesExpandedVisibility}" />
-        <TextBox Grid.Row="6" Grid.Column="1" Text="{Binding ContentEncoding, UpdateSourceTrigger=PropertyChanged}" Visibility="{Binding PropertiesExpandedVisibility}" />
+        <TextBox Grid.Row="6" Grid.Column="1" Text="{Binding Expiration, UpdateSourceTrigger=PropertyChanged}" Visibility="{Binding PropertiesExpandedVisibility}" />
 
-        <Label Grid.Row="7" Grid.Column="0" Content="{x:Static publisher:RawPublisherViewStrings.LabelExpiration}" Visibility="{Binding PropertiesExpandedVisibility}" />
+        <Label Grid.Row="7" Grid.Column="0" Content="{x:Static publisher:RawPublisherViewStrings.LabelMessageId}" Visibility="{Binding PropertiesExpandedVisibility}" />
-        <TextBox Grid.Row="7" Grid.Column="1" Text="{Binding Expiration, UpdateSourceTrigger=PropertyChanged}" Visibility="{Binding PropertiesExpandedVisibility}" />
+        <TextBox Grid.Row="7" Grid.Column="1" Text="{Binding MessageId, UpdateSourceTrigger=PropertyChanged}" Visibility="{Binding PropertiesExpandedVisibility}" />
 
-        <Label Grid.Row="8" Grid.Column="0" Content="{x:Static publisher:RawPublisherViewStrings.LabelMessageId}" Visibility="{Binding PropertiesExpandedVisibility}" />
+        <Label Grid.Row="8" Grid.Column="0" Content="{x:Static publisher:RawPublisherViewStrings.LabelPriority}" Visibility="{Binding PropertiesExpandedVisibility}" />
-        <TextBox Grid.Row="8" Grid.Column="1" Text="{Binding MessageId, UpdateSourceTrigger=PropertyChanged}" Visibility="{Binding PropertiesExpandedVisibility}" />
+        <TextBox Grid.Row="8" Grid.Column="1" Text="{Binding Priority, UpdateSourceTrigger=PropertyChanged}" Visibility="{Binding PropertiesExpandedVisibility}" />
 
-        <Label Grid.Row="9" Grid.Column="0" Content="{x:Static publisher:RawPublisherViewStrings.LabelPriority}" Visibility="{Binding PropertiesExpandedVisibility}" />
+        <Label Grid.Row="9" Grid.Column="0" Content="{x:Static publisher:RawPublisherViewStrings.LabelTimestamp}" Visibility="{Binding PropertiesExpandedVisibility}" />
-        <TextBox Grid.Row="9" Grid.Column="1" Text="{Binding Priority, UpdateSourceTrigger=PropertyChanged}" Visibility="{Binding PropertiesExpandedVisibility}" />
+        <TextBox Grid.Row="9" Grid.Column="1" Text="{Binding Timestamp, UpdateSourceTrigger=PropertyChanged}" Visibility="{Binding PropertiesExpandedVisibility}" />
 
-        <Label Grid.Row="10" Grid.Column="0" Content="{x:Static publisher:RawPublisherViewStrings.LabelTimestamp}" Visibility="{Binding PropertiesExpandedVisibility}" />
+        <Label Grid.Row="10" Grid.Column="0" Content="{x:Static publisher:RawPublisherViewStrings.LabelType}" Visibility="{Binding PropertiesExpandedVisibility}" />
-        <TextBox Grid.Row="10" Grid.Column="1" Text="{Binding Timestamp, UpdateSourceTrigger=PropertyChanged}" Visibility="{Binding PropertiesExpandedVisibility}" />
+        <TextBox Grid.Row="10" Grid.Column="1" Text="{Binding TypeProperty, UpdateSourceTrigger=PropertyChanged}" Visibility="{Binding PropertiesExpandedVisibility}" />
 
-        <Label Grid.Row="11" Grid.Column="0" Content="{x:Static publisher:RawPublisherViewStrings.LabelType}" Visibility="{Binding PropertiesExpandedVisibility}" />
+        <Label Grid.Row="11" Grid.Column="0" Content="{x:Static publisher:RawPublisherViewStrings.LabelUserId}" Visibility="{Binding PropertiesExpandedVisibility}" />
-        <TextBox Grid.Row="11" Grid.Column="1" Text="{Binding TypeProperty, UpdateSourceTrigger=PropertyChanged}" Visibility="{Binding PropertiesExpandedVisibility}" />
+        <TextBox Grid.Row="11" Grid.Column="1" Text="{Binding UserId, UpdateSourceTrigger=PropertyChanged}" Visibility="{Binding PropertiesExpandedVisibility}" />
-
-        <Label Grid.Row="12" Grid.Column="0" Content="{x:Static publisher:RawPublisherViewStrings.LabelUserId}" Visibility="{Binding PropertiesExpandedVisibility}" />
-        <TextBox Grid.Row="12" Grid.Column="1" Text="{Binding UserId, UpdateSourceTrigger=PropertyChanged}" Visibility="{Binding PropertiesExpandedVisibility}" />
 
 
-        <Button Grid.Row="13" Grid.Column="1" Content="{Binding PropertiesExpandedCollapsedText}" Command="{Binding PropertiesExpandCollapseCommand}" Cursor="Hand">
+        <Button Grid.Row="12" Grid.Column="1" Content="{Binding PropertiesExpandedCollapsedText}" Command="{Binding PropertiesExpandCollapseCommand}" Cursor="Hand">
             <Button.Template>
                 <ControlTemplate TargetType="{x:Type Button}">
                     <ContentPresenter />
@@ -134,7 +130,7 @@
             </Button.Template>
         </Button>
 
-        <Label Grid.Row="15" Grid.Column="0" Content="{x:Static publisher:RawPublisherViewStrings.LabelPayload}" />
+        <Label Grid.Row="14" Grid.Column="0" Content="{x:Static publisher:RawPublisherViewStrings.LabelPayload}" />
-        <TextBox Grid.Row="15" Grid.Column="1" Text="{Binding Payload, UpdateSourceTrigger=PropertyChanged}" Style="{StaticResource Payload}" Height="150" />
+        <publisher:PayloadEditorControl Grid.Row="14" Grid.Column="1" Payload="{Binding Payload}" ContentType="{Binding ContentType}" Height="350"/>
     </ui:GridLayout>
 </UserControl>

PettingZoo/UI/Tab/Publisher/TapetiPublisherView.xaml

@@ -48,6 +48,6 @@
         </Grid>
 
         <Label Grid.Row="6" Grid.Column="0" Content="{x:Static publisher:TapetiPublisherViewStrings.LabelPayload}" />
-        <TextBox Grid.Row="6" Grid.Column="1" Text="{Binding Payload, UpdateSourceTrigger=PropertyChanged}" Style="{StaticResource Payload}" Height="150" />
+        <publisher:PayloadEditorControl Grid.Row="6" Grid.Column="1" Payload="{Binding Payload}" FixedJson="True" Height="350"/>
     </ui:GridLayout>
 </UserControl>