implemented serial protocol,

made changes to CommunicationProtocol,
added ILibraryEquivalentConverter to convert library types to local types,
added Messenger to App,
implemented UserInterfaceMessages

Common/Messaging/IUserInterfaceMessage.cs

@@ -0,0 +1,18 @@
+namespace Common.Messaging;
+
+/// <summary>
+/// Interface represents a user interface message.
+/// </summary>
+public interface IUserInterfaceMessage
+{
+    /// <summary>
+    /// Converst message to string that is displayed to user.
+    /// </summary>
+    /// <returns>string to be displayed to user</returns>
+    string ToString();
+
+    /// <summary>
+    /// Defines how prominent the message shall be displayed to the user.
+    /// </summary>
+    MessageImportance Importance { get; }
+}

Common/Messaging/MessageImportance.cs

@@ -0,0 +1,28 @@
+namespace Common.Messaging;
+
+public enum MessageImportance
+{
+    /// <summary>
+    /// Normal importance.
+    /// Message is displayed but user might not recognize it immediately.
+    /// </summary>
+    Normal,
+
+    /// <summary>
+    /// Medium importance.
+    /// Message is displayed so user should recognizes it in a matter of seconds.
+    /// </summary>
+    Medium,
+
+    /// <summary>
+    /// High importance.
+    /// Message is prominently displayed so user should recognize it immediately.
+    /// </summary>
+    High,
+
+    /// <summary>
+    /// High importance.
+    /// User is interrupted with this very prominently displayed message and needs to confirm the message.
+    /// </summary>
+    HighAndRequiresConfirmation
+}

MultiTerm.Core/ViewModel/ShellViewModel.cs

@@ -7,10 +7,12 @@ using MultiTerm.Core.Factories;
 using System.Collections.ObjectModel;
 using MultiTerm.Core.Types;
 using MultiTerm.Protocols.Types;
+using CommunityToolkit.Mvvm.Messaging;
+using Common.Messaging;
 
 namespace MultiTerm.Core.ViewModel;
 
-public partial class ShellViewModel : ObservableObject
+public partial class ShellViewModel : ObservableObject, IRecipient<IUserInterfaceMessage>
 {
     private const string defaultReceiveNewlineSeparatorAppSettingsKey = "DefaultReceiveNewlineSeparator";
     private const string defaultSendNewlineSeparatorAppSettingsKey = "DefaultSendNewlineSeparator";
@@ -36,19 +38,32 @@ public partial class ShellViewModel : ObservableObject
     private TerminalViewType selectedTerminalViewType = TerminalViewType.SendReceive;
     #endregion
 
+    #region Status Bar
+    [ObservableProperty]
+    private string statusBarMessage = "";
+
+    [ObservableProperty]
+    private MessageImportance statusBarMessageImportance = MessageImportance.Normal;
+    #endregion
+
     private readonly ITerminalViewModelFactory terminalViewModelFactory;
     private readonly ILogger logger;
     private readonly IAppSettingsProvider appSettings;
+    private readonly IMessenger messenger;
 
-    public ShellViewModel(ITerminalViewModelFactory terminalViewModelFactory, ILogger logger, IAppSettingsProvider appSettings)
+    public ShellViewModel(ITerminalViewModelFactory terminalViewModelFactory, ILogger logger, IAppSettingsProvider appSettings, IMessenger messenger)
     {
         this.terminalViewModelFactory = terminalViewModelFactory;
         this.logger = logger;
         this.appSettings = appSettings;
+        this.messenger = messenger;
 
         // intialize values from app settings
         this.LoadFromAppSettings();
 
+        // register to messages
+        this.messenger.Register(this);
+
         // TEMP Init
         this.AppendTerminalWithSelectedViewType(ProtocolType.Serial);
     }
@@ -110,4 +125,12 @@ public partial class ShellViewModel : ObservableObject
         this.appSettings.WriteSetting(defaultSendNewlineSeparatorAppSettingsKey, value.ToString());
     }
     #endregion
+
+    #region Messaging handling
+    public void Receive(IUserInterfaceMessage message)
+    {
+        this.StatusBarMessage = message.ToString();
+        this.StatusBarMessageImportance = message.Importance;
+    }
+    #endregion
 }

MultiTerm.Core/ViewModel/TerminalViewModel.cs

@@ -26,7 +26,7 @@ public abstract partial class TerminalViewModel : ObservableObject, ITerminalVie
             // register event handler for connection request from viewmodel
             if(value != null)
             {
-                protocolSettings!.ConnectRequested += OnViewModelRequestedConnect;
+                protocolSettings!.ConnectRequested += OnViewModelRequestedConnect; ;
                 protocolSettings!.DisconnectRequested += OnViewModelRequestedDisconnect;
             }
         }
@@ -49,9 +49,9 @@ public abstract partial class TerminalViewModel : ObservableObject, ITerminalVie
         }
     }
 
-    private void OnViewModelRequestedConnect(object? sender, EventArgs e)
+    private void OnViewModelRequestedConnect(object? sender, IProtocolSettings e)
     {
-        this.CommunicationProtocol?.Connect();
+        this.CommunicationProtocol?.Connect(e);
     }
 
     private void OnViewModelRequestedDisconnect(object? sender, EventArgs e)

MultiTerm.Protocols/CommunicationProtocol.cs

@@ -1,4 +1,5 @@
 using Common.Logging;
+using CommunityToolkit.Mvvm.Messaging;
 using MultiTerm.Protocols.Types;
 
 namespace MultiTerm.Protocols;
@@ -9,7 +10,6 @@ public abstract class CommunicationProtocol : ICommunicationProtocol
     private CancellationTokenSource cancellationTokenSource;
     private Thread? readingThread;
 
-    public IProtocolSettings? Settings { get; set; }
     public event EventHandler<ReceivedDataEventArgs>? ReceivedDataEvent;
     public event EventHandler<SentDataEventArgs>? SentDataEvent;
 
@@ -48,8 +48,9 @@ public abstract class CommunicationProtocol : ICommunicationProtocol
     /// <summary>
     /// Allows to connect to the selected device using the implemented protocol.
     /// </summary>
+    /// <param name="settings">protocol settings required to connect</param>
     /// <returns>true on success</returns>
-    protected abstract bool InternalConnect();
+    protected abstract bool InternalConnect(IProtocolSettings settings);
 
     /// <summary>
     /// Reads from the connected device in an endless loop.
@@ -58,9 +59,17 @@ public abstract class CommunicationProtocol : ICommunicationProtocol
     /// <param name="ct">cancellation token</param>
     protected abstract void InternalRead(CancellationToken ct);
 
-    public void Connect()
+    public void Connect(IProtocolSettings settings)
     {
-        if (this.InternalConnect())
+        // check if settings are valid, cancel if not
+        if (settings.AreValid() == false)
+        {
+            this.logger.LogError($"'{nameof(Connect)}()' failed since the provided protocol settings are invalid", nameof(CommunicationProtocol));
+            return;
+        }
+
+        // try connecting if serttings are valid
+        if (this.InternalConnect(settings))
         {
             // renew token source
             this.cancellationTokenSource = new CancellationTokenSource();

MultiTerm.Protocols/ICommunicationProtocol.cs

@@ -12,11 +12,6 @@ public interface ICommunicationProtocol
     /// </summary>
     ProtocolType ProtocolType { get; }
 
-    /// <summary>
-    /// Contains settings that are required to connect and use this communication protocol.
-    /// </summary>
-    IProtocolSettings? Settings { get; }
-
     /// <summary>
     /// New data received from connected device.
     /// </summary>
@@ -30,7 +25,8 @@ public interface ICommunicationProtocol
     /// <summary>
     /// Connect to the device.
     /// </summary>
-    void Connect();
+    /// <param name="settings">settings required to connect and use the protocol</param>
+    void Connect(IProtocolSettings settings);
 
     /// <summary>
     /// Disconnect from the device. Ends all internal activities.

MultiTerm.Protocols/ILibraryEquivalentConverter.cs

@@ -0,0 +1,23 @@
+namespace MultiTerm.Protocols;
+
+/// <summary>
+/// Interface for a converter that converts a facade type into the equivalent of the related software library.
+/// </summary>
+/// <typeparam name="T_local">type of the local class</typeparam>
+/// <typeparam name="T_library">type of the library class</typeparam>
+internal interface ILibraryEquivalentConverter<T_local, T_library>
+{
+    /// <summary>
+    /// Convert the object to the library type.
+    /// </summary>
+    /// <param name="obj">object of local class</param>
+    /// <returns>object of class within library</returns>
+    T_library ConvertToLibraryType(T_local obj);
+
+    /// <summary>
+    /// Convert the object to the local type.
+    /// </summary>
+    /// <param name="obj">object of class within library</param>
+    /// <returns>object of local class</returns>
+    T_local ConvertToLocalType(T_library obj);
+}

MultiTerm.Protocols/IProtocolSettings.cs

@@ -15,5 +15,6 @@ public interface IProtocolSettings
     /// <summary>
     /// Checks if the entered settings are valid and a connection can be made.
     /// </summary>
-    void AreValid();
+    /// <returns>true if the settings are valid</returns>
+    bool AreValid();
 }

MultiTerm.Protocols/IProtocolSettingsViewModel.cs

@@ -11,8 +11,9 @@ public interface IProtocolSettingsViewModel
 
     /// <summary>
     /// Event that is thrown when the user requested to connect to the device with the entered settings.
+    /// Provides protocol settings to use for connection.
     /// </summary>
-    event EventHandler? ConnectRequested;
+    event EventHandler<IProtocolSettings> ConnectRequested;
 
     /// <summary>
     /// Event that is thrown when the user requested to disconnect from the device.

MultiTerm.Protocols/MultiTerm.Protocols.csproj

@@ -8,6 +8,7 @@
 
   <ItemGroup>
     <PackageReference Include="CommunityToolkit.Mvvm" Version="8.1.0" />
+    <PackageReference Include="SerialPortStream" Version="2.4.1" />
   </ItemGroup>
 
   <ItemGroup>

MultiTerm.Protocols/ProtocolSettingsViewModel.cs

@@ -1,5 +1,6 @@
 using CommunityToolkit.Mvvm.ComponentModel;
 using CommunityToolkit.Mvvm.Input;
+using CommunityToolkit.Mvvm.Messaging;
 using MultiTerm.Protocols.Types;
 
 namespace MultiTerm.Protocols;
@@ -7,13 +8,15 @@ namespace MultiTerm.Protocols;
 /// <summary>
 /// Class that represents all connection and usage settings for a specific <see cref="CommunicationProtocol"/>.
 /// Can be bound to UI using MVVM pattern.
+/// Implementing class must also implement <see cref="IProtocolSettings"/>! Otherwise <see cref="ConnectDisconnectCommand"/> does not work.
 /// </summary>
 public abstract partial class ProtocolSettingsViewModel : ObservableObject, IProtocolSettingsViewModel
 {
     private const string connectedStateButtonText = "Disconnect";
     private const string disconnectedStateButtonText = "Connect";
+    protected readonly IMessenger messenger;
 
-    public event EventHandler? ConnectRequested;
+    public event EventHandler<IProtocolSettings>? ConnectRequested;
     public event EventHandler? DisconnectRequested;
 
     public abstract ProtocolType ProtocolType { get; }
@@ -27,10 +30,15 @@ public abstract partial class ProtocolSettingsViewModel : ObservableObject, IPro
     [ObservableProperty]
     private string connectDisconnectButtonText = disconnectedStateButtonText;
 
+    public ProtocolSettingsViewModel(IMessenger messenger)
+    {
+        this.messenger = messenger;
+    }
 
     /// <summary>
     /// Binding to Connect/Disconnect button.
     /// Button text is provided in <see cref="ConnectDisconnectButtonText"/>
+    /// Implementing class must also implement <see cref="IProtocolSettings"/>! Otherwise <see cref="ConnectDisconnectCommand"/> does not work.
     /// </summary>
     [RelayCommand(AllowConcurrentExecutions = false)]
     private async Task ConnectDisconnectAsync()
@@ -42,7 +50,7 @@ public abstract partial class ProtocolSettingsViewModel : ObservableObject, IPro
             {
                 // CONNECT
                 this.AreEditable = false;
-                this.ConnectRequested?.Invoke(this, EventArgs.Empty);
+                this.ConnectRequested?.Invoke(this, (IProtocolSettings)this);  // implementing class must also implement IProtocolSettings!
                 this.ConnectDisconnectButtonText = connectedStateButtonText;
             }
             // if currently connected

MultiTerm.Protocols/Serial/Handshake.cs

@@ -0,0 +1,74 @@
+using System.ComponentModel;
+
+using Library = RJCP.IO.Ports;
+
+namespace MultiTerm.Protocols.Serial;
+
+public enum Handshake
+{
+    //
+    // Summary:
+    //     No handshaking.
+    [Description("None")]
+    None = 0x0,
+    //
+    // Summary:
+    //     Software handshaking.
+    [Description("XON")]
+    XOn = 0x1,
+    //
+    // Summary:
+    //     Hardware handshaking (RTS/CTS).
+    [Description("RTS")]
+    Rts = 0x2,
+    //
+    // Summary:
+    //     Hardware handshaking (DTR/DSR) (uncommon).
+    [Description("DTR")]
+    Dtr = 0x4,
+    //
+    // Summary:
+    //     RTS and Software handshaking.
+    [Description("RTS XON")]
+    RtsXOn = 0x3,
+    //
+    // Summary:
+    //     DTR and Software handshaking (uncommon).
+    [Description("DTR XON")]
+    DtrXOn = 0x5,
+    //
+    // Summary:
+    //     Hardware handshaking with RTS/CTS and DTR/DSR (uncommon).
+    [Description("DTR RTS")]
+    DtrRts = 0x6,
+    //
+    // Summary:
+    //     Hardware handshaking with RTS/CTS and DTR/DSR and Software handshaking (uncommon).
+    [Description("DTR RTS XON")]
+    DtrRtsXOn = 0x7
+}
+
+internal class HandshakeLibraryEquivalentConverter : ILibraryEquivalentConverter<Handshake, Library.Handshake>
+{
+    public Library.Handshake ConvertToLibraryType(Handshake obj)
+    {
+        return obj switch
+        {
+            Handshake.None => Library.Handshake.None,
+            Handshake.XOn => Library.Handshake.XOn,
+            Handshake.Rts => Library.Handshake.Rts,
+            Handshake.Dtr => Library.Handshake.Dtr,
+            Handshake.RtsXOn => Library.Handshake.RtsXOn,
+            Handshake.DtrXOn => Library.Handshake.DtrXOn,
+            Handshake.DtrRts => Library.Handshake.DtrRts,
+            Handshake.DtrRtsXOn => Library.Handshake.DtrRtsXOn,
+            _ => throw new NotImplementedException(),
+        };
+    }
+
+    public Handshake ConvertToLocalType(Library.Handshake obj)
+    {
+        throw new NotImplementedException();
+    }
+}
+

MultiTerm.Protocols/Serial/ISerialProtocolSettings.cs

@@ -2,6 +2,34 @@
 
 public interface ISerialProtocolSettings : IProtocolSettings
 {
-    //TODO
+    /// <summary>
+    /// Port for communication, e.g. COM3 or com50.
+    /// </summary>
+    string PortName { get; set; }
+
+    /// <summary>
+    /// Serial Baud rate.
+    /// </summary>
     int BaudRate { get; set; }
+
+    /// <summary>
+    /// The type of parity to use.
+    /// </summary>
+    Parity Parity { get; set; }
+
+    /// <summary>
+    /// The standard length of data bits per byte.
+    /// </summary>
+    int DataBits { get; set; }
+
+    /// <summary>
+    /// Number of stop bits to use.
+    /// </summary>
+    StopBits StopBits { get; set; }
+
+    /// <summary>
+    /// Handshaking protocol for serial port transmission of data.
+    /// </summary>
+    Handshake Handshake { get; set; }
+
 }

MultiTerm.Protocols/Serial/Parity.cs

@@ -0,0 +1,56 @@
+using System.ComponentModel;
+
+using Library = RJCP.IO.Ports;
+
+namespace MultiTerm.Protocols.Serial;
+
+public enum Parity
+{
+    //
+    // Summary:
+    //     No parity.
+    [Description("None")]
+    None,
+    //
+    // Summary:
+    //     Odd parity.
+    [Description("Odd")]
+    Odd,
+    //
+    // Summary:
+    //     Even parity.
+    [Description("Even")]
+    Even,
+    //
+    // Summary:
+    //     Mark parity.
+    [Description("Mark")]
+    Mark,
+    //
+    // Summary:
+    //     Space parity.
+    [Description("Space")]
+    Space
+}
+
+internal class ParityLibraryEquivalentConverter : ILibraryEquivalentConverter<Parity, Library.Parity>
+{
+    public Library.Parity ConvertToLibraryType(Parity obj)
+    {
+        return obj switch
+        {
+            Parity.None => Library.Parity.None,
+            Parity.Odd => Library.Parity.Odd,
+            Parity.Even => Library.Parity.Even,
+            Parity.Mark => Library.Parity.Mark,
+            Parity.Space => Library.Parity.Space,
+            _ => throw new NotImplementedException(),
+        };
+    }
+
+    public Parity ConvertToLocalType(Library.Parity obj)
+    {
+        throw new NotImplementedException();
+    }
+}
+

MultiTerm.Protocols/Serial/SerialProtocol.cs

@@ -1,34 +1,96 @@
 using Common.Logging;
+using MultiTerm.Protocols.Model;
 using MultiTerm.Protocols.Types;
+using RJCP.IO.Ports;
+using System.Text;
 
 namespace MultiTerm.Protocols.Serial;
 
 public class SerialProtocol : CommunicationProtocol
 {
     public override ProtocolType ProtocolType => ProtocolType.Serial;
+    private ISerialProtocolSettings? serialSettings;
+    private SerialPortStream serialPort = new();
 
-    public SerialProtocol(ILogger logger) : base(logger)
-    {
 
+    public SerialProtocol(ILogger logger) : base(logger) { }
+
+    protected override bool InternalConnect(IProtocolSettings protocolSettings)
+    {
+        // check if settings are of correct type
+        if (protocolSettings is not ISerialProtocolSettings serialProtocolSettings) 
+        {
+            this.serialSettings = null;
+            throw new ArgumentException($"Cannot connect due to wrong type of Protocol Settings. " +
+                $"Check parameter {nameof(protocolSettings)}' of '{nameof(InternalConnect)}()' in {nameof(SerialProtocol)}.");
         }
 
-    protected override bool InternalConnect()
+        // store locally
+        this.serialSettings = serialProtocolSettings;
+
+        // create new serial port
+        this.serialPort = new()
         {
-        throw new NotImplementedException();
+            // apply user settings, where needed converters are used
+            PortName = this.serialSettings.PortName,
+            BaudRate = this.serialSettings.BaudRate,
+            DataBits = this.serialSettings.DataBits,
+            Parity = new ParityLibraryEquivalentConverter().ConvertToLibraryType(this.serialSettings.Parity),
+            StopBits = new StopBitsLibraryEquivalentConverter().ConvertToLibraryType(this.serialSettings.StopBits),
+            Handshake = new HandshakeLibraryEquivalentConverter().ConvertToLibraryType(this.serialSettings.Handshake),
+
+            // define static settings
+            Encoding = Encoding.Unicode,
+            ReadTimeout = 500,
+            WriteTimeout = 500
+        };
+
+        // try opening serial port
+        try
+        {
+            serialPort.Open();
+        }
+        catch (Exception ex)
+        {
+            this.logger.LogException(ex, $"'{nameof(InternalConnect)}()'Opening serial port failed:", nameof(SerialProtocol));
+            return false;
+        }
+        return true;
     }
 
     protected override void InternalDisconnect()
     {
-        throw new NotImplementedException();
+        serialPort.Close();
+        this.serialSettings = null;
     }
 
     protected override void InternalRead(CancellationToken ct)
     {
-        throw new NotImplementedException();
+        while(ct.IsCancellationRequested == false)
+        {
+            // reads character based on configured encoding (here Unicode)
+            int readCharacter = serialPort.ReadChar();  
+            if (readCharacter != -1) // -1 = timeout
+            {
+                // create extended char type
+                var character = new ExtendedChar((char)readCharacter);
+
+                // report new data with event
+                this.OnReceivedData(new ReceivedDataEventArgs(new ExtendedChar[] { character }));
+            }
+        }
     }
 
     protected override void InternalSendBytes(byte[] bytes)
     {
-        throw new NotImplementedException();
+        foreach (byte b in bytes)
+        {
+            serialPort.WriteByte(b);
+        }
+    }
+
+    public static IEnumerable<string> GetPortNames()
+    {
+        return SerialPortStream.GetPortNames();
     }
 }

MultiTerm.Protocols/Serial/SerialProtocolSettingsViewModel.cs

@@ -1,4 +1,6 @@
-using CommunityToolkit.Mvvm.ComponentModel;
+using Common.Messaging;
+using CommunityToolkit.Mvvm.ComponentModel;
+using CommunityToolkit.Mvvm.Messaging;
 using MultiTerm.Protocols.Types;
 
 namespace MultiTerm.Protocols.Serial;
@@ -8,16 +10,50 @@ public partial class SerialProtocolSettingsViewModel : ProtocolSettingsViewModel
     public override ProtocolType ProtocolType => ProtocolType.Serial;
 
     [ObservableProperty]
-    private int baudRate;
+    private int baudRate = 115200;
-    //public int BaudRate { get => throw new NotImplementedException(); set => throw new NotImplementedException(); }
 
+    [ObservableProperty]
+    private string portName = "";
+
+    [ObservableProperty]
+    private Parity parity = Parity.None;
+
+    [ObservableProperty]
+    private int dataBits = 8;
+
+    [ObservableProperty]
+    private StopBits stopBits = StopBits.One;
+
+    [ObservableProperty]
+    private Handshake handshake = Handshake.None;
+
+
+    // TODO 
     public string NewlineSequenceOnSend => throw new NotImplementedException();
 
     public string NewlineOnReceivedSequence => throw new NotImplementedException();
 
 
-    public void AreValid()
+    public SerialProtocolSettingsViewModel(IMessenger messenger) : base(messenger) { }
+
+    public bool AreValid()
+    {
+        if (String.IsNullOrEmpty(this.PortName))
+        {
+            this.messenger.Send<IUserInterfaceMessage>(new ProtocolSettingsInvalidMessage(nameof(this.PortName), "Null or empty"));
+            return false;
+        }
+        if (this.PortName.ToLower().StartsWith("com") == false) 
         {
-        throw new NotImplementedException();
+            this.messenger.Send<IUserInterfaceMessage>(new ProtocolSettingsInvalidMessage(nameof(this.PortName), "Must start with COM"));
+            return false;
+        }
+        if (this.DataBits < 5 && this.DataBits > 8 && this.DataBits != 16)
+        {
+            this.messenger.Send<IUserInterfaceMessage>(new ProtocolSettingsInvalidMessage(nameof(this.DataBits), "Must be 5...8 or 16"));
+            return false;
+        }
+
+        return true;
     }
 }

MultiTerm.Protocols/Serial/StopBits.cs

@@ -0,0 +1,44 @@
+using System.ComponentModel;
+
+using Library = RJCP.IO.Ports;
+
+namespace MultiTerm.Protocols.Serial;
+
+public enum StopBits
+{
+    //
+    // Summary:
+    //     One stop bit.
+    [Description("1")]
+    One,
+    //
+    // Summary:
+    //     1.5 stop bits.
+    [Description("1.5")]
+    One5,
+    //
+    // Summary:
+    //     Two stop bits.
+    [Description("2")]
+    Two
+}
+
+internal class StopBitsLibraryEquivalentConverter : ILibraryEquivalentConverter<StopBits, Library.StopBits>
+{
+    public Library.StopBits ConvertToLibraryType(StopBits obj)
+    {
+        return obj switch
+        {
+            StopBits.One => Library.StopBits.One,
+            StopBits.One5 => Library.StopBits.One5,
+            StopBits.Two => Library.StopBits.Two,
+            _ => throw new NotImplementedException(),
+        };
+    }
+
+    public StopBits ConvertToLocalType(Library.StopBits obj)
+    {
+        throw new NotImplementedException();
+    }
+}
+

MultiTerm.Protocols/Types/ProtocolSettingsInvalidMessage.cs

@@ -0,0 +1,22 @@
+using Common.Messaging;
+
+namespace MultiTerm.Protocols.Types;
+
+public sealed class ProtocolSettingsInvalidMessage : IUserInterfaceMessage
+{
+    public MessageImportance Importance => MessageImportance.Medium;
+
+    public string SettingName { get; }
+    public string Message { get; }
+
+    public ProtocolSettingsInvalidMessage(string settingName, string message)
+    {
+        this.SettingName = settingName;
+        this.Message = message;
+    }
+
+    public override string ToString()
+    {
+        return $"Protocol setting '{this.SettingName}' is invalid: {this.Message}";
+    }
+}

MultiTerm.Wpf/App.xaml.cs

@@ -8,6 +8,7 @@ using System;
 using System.Threading.Tasks;
 using Common.AppSettings;
 using MultiTerm.Protocols.Helpers;
+using CommunityToolkit.Mvvm.Messaging;
 
 namespace MultiTerm.Wpf;
 
@@ -26,6 +27,7 @@ public partial class App : Application
                 services.AddSingleton<MainWindow>();
                 services.AddSingleton<ILogger>(new SerilogLogger("C:/log/multiterm-log-.txt", true));
                 services.AddSingleton<IAppSettingsProvider>(new XmlAppSettingsProvider("C:/log/multiterm-config.xml"));
+                services.AddSingleton<IMessenger, WeakReferenceMessenger>();
 
                 // viewmodels
                 services.AddSingleton<ShellViewModel>();

MultiTerm.Wpf/ValueConverters/MessageImportanceToBrushConverter.cs

@@ -0,0 +1,33 @@
+using Common.Messaging;
+using System;
+using System.Globalization;
+using System.Windows.Controls;
+using System.Windows.Data;
+using System.Windows.Media;
+
+namespace MultiTerm.Wpf.ValueConverters;
+
+[ValueConversion(typeof(MessageImportance), typeof(Brush))]
+
+internal class MessageImportanceToBrushConverter : IValueConverter
+{
+    public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
+    {
+        if(value is not MessageImportance msgImportance) 
+        { throw new ArgumentException($"Wrong object provided, can only convert from type {nameof(MessageImportance)}"); }
+
+        return msgImportance switch
+        {
+            MessageImportance.Normal => Brushes.Black,
+            MessageImportance.Medium => Brushes.DarkSalmon,
+            MessageImportance.High => Brushes.Red,
+            MessageImportance.HighAndRequiresConfirmation => throw new NotImplementedException(),
+            _ => throw new NotImplementedException(),
+        };
+    }
+
+    public object ConvertBack(object value, Type targetType, object parameter, CultureInfo culture)
+    {
+        throw new NotImplementedException();
+    }
+}

MultiTerm.Wpf/View/ShellView.xaml

@@ -17,6 +17,7 @@
     <UserControl.Resources>
         <!-- Value Converters -->
         <conv:EnumDescriptionToMenuItemConverter x:Key="EnumDescriptionConverter"/>
+        <conv:MessageImportanceToBrushConverter x:Key="MsgImportanceBrushConverter"/>
         
         <!-- Data Sources -->
         <ObjectDataProvider x:Key="NewlineSeparatorTypeValues"
@@ -71,6 +72,14 @@
             <MenuItem Header="_About"/>
         </Menu>
 
+        <!-- Bottom status bar with separator -->
+        <StatusBar DockPanel.Dock="Bottom">
+            <StatusBarItem>
+                <TextBlock Text="{Binding StatusBarMessage}" Foreground="{Binding Path=StatusBarMessageImportance, Converter={StaticResource MsgImportanceBrushConverter}}"/>
+            </StatusBarItem>
+        </StatusBar>
+        <Separator DockPanel.Dock="Bottom" Margin="0 5 0 5"/>
+
         <!-- Left Panel that holds History and Command Sets -->
         <StackPanel Orientation="Vertical" DockPanel.Dock="Left" Width="150">