created initial functionality for WPF UI

ADIS_Csharp/RobotClientWpf/ChallengeFactory.cs

@@ -0,0 +1,19 @@
+using RobotLib;
+using RobotLib.Communication;
+
+namespace RobotClientWpf
+{
+    internal class ChallengeFactory
+    {
+        public MqttPublisherSubscriber PublisherSubscriber { get; }
+        public Robot RobotStationary { get; }
+        public Robot RobotMobile { get; }
+
+        public ChallengeFactory()
+        {
+            this.PublisherSubscriber = MqttPublisherSubscriber.Instance;
+            //this.RobotStationary = new Robot(this.PublisherSubscriber);
+            //this.RobotMobile = new Robot(this.PublisherSubscriber);
+        }
+    }
+}

ADIS_Csharp/RobotClientWpf/IUiService.cs

@@ -0,0 +1,15 @@
+namespace RobotClientWpf
+{
+    public interface IUiService
+    {
+        void DisplayBottomMessage(MessageSeverity severity, string message);
+    }
+    public enum MessageSeverity
+    {
+        Unknown = 0,
+        Success,
+        Warning,
+        Error,
+        Information
+    }
+}

ADIS_Csharp/RobotClientWpf/MainWindow.xaml

@@ -4,11 +4,50 @@
         xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
         xmlns:local="clr-namespace:RobotClientWpf"
-        mc:Ignorable="d"
-        Title="RobotClientWpf" Height="450" Width="800">
+        xmlns:views="clr-namespace:RobotClientWpf.Views"
+        mc:Ignorable="d" FontSize="15"
+        Title="Challenge UI" Height="700" Width="1200" WindowStartupLocation="CenterScreen" ResizeMode="NoResize">
     <Grid>
-        <Button x:Name="buttonBuzz" Content="Beep" HorizontalAlignment="Left" Margin="246,86,0,0" VerticalAlignment="Top" Click="buttonBuzz_Click"/>
-        <Label x:Name="labelBattery" Content="Battery: 1.25V" HorizontalAlignment="Left" Margin="22,27,0,0" VerticalAlignment="Top"/>
+        <Grid.RowDefinitions>
+            <RowDefinition Height="40"/>
+            <RowDefinition Height="*"/>
+            <RowDefinition Height="30"/>
+        </Grid.RowDefinitions>
 
+        <StackPanel Grid.Row="0" Orientation="Horizontal" Margin="5">
+            <Label HorizontalAlignment="Center">MQTT Broker IP: </Label>
+            <TextBox x:Name="tbIp" Width="120" Height="25" FontSize="15" TextAlignment="Left" Margin="10 0 0 0">192.168.156.156</TextBox>
+            <Button x:Name="btnConnectDisconnect" Content="Connect" Width="100" Margin="20 0 0 0" Click="btnConnectDisconnect_Click"></Button>
+        </StackPanel>
+
+        <TabControl Grid.Row="1" x:Name="tabControlMain">
+            <TabControl.ItemContainerStyle>
+                <Style TargetType="{x:Type TabItem}">
+                    <Setter Property="Header" Value="{Binding Header}" />
+                </Style>
+            </TabControl.ItemContainerStyle>
+            <TabItem>
+                <TabItem.Header>
+                    <StackPanel Orientation="Horizontal">
+                        <Image Source="/Assets/robot-industrial.png" Height="18" />
+                        <TextBlock Text="  Main" Foreground="Green" FontSize="16" />
+                    </StackPanel>
+                </TabItem.Header>
+                <views:MainView/>
+            </TabItem>
+            <TabItem>
+                <TabItem.Header>
+                    <StackPanel Orientation="Horizontal">
+                        <Image Source="/Assets/cog.png" Height="18" />
+                        <TextBlock Text="  Config" Foreground="Blue" FontSize="16"/>
+                    </StackPanel>
+                </TabItem.Header>
+                <views:ConfigView/>
+            </TabItem>
+        </TabControl>
+
+        <StackPanel Grid.Row="2" Orientation="Horizontal">
+            <TextBlock x:Name="tbBottomMessage" FontSize="15" Margin="10 5"/>
+        </StackPanel>
     </Grid>
 </Window>

ADIS_Csharp/RobotClientWpf/MainWindow.xaml.cs

@@ -1,17 +1,9 @@
 using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
+using System.Net;
 using System.Threading.Tasks;
 using System.Windows;
-using System.Windows.Controls;
-using System.Windows.Data;
-using System.Windows.Documents;
-using System.Windows.Input;
 using System.Windows.Media;
-using System.Windows.Media.Imaging;
-using System.Windows.Navigation;
-using System.Windows.Shapes;
+using RobotClientWpf.Utilities;
 using RobotLib;
 
 namespace RobotClientWpf
@@ -21,11 +13,24 @@ namespace RobotClientWpf
     /// </summary>
     public partial class MainWindow : Window
     {
+        private ChallengeFactory challenge;
+        private bool manualDisconnect;
+
         public MainWindow()
         {
             InitializeComponent();
-            Robot.Instance.Connect("host", 1818);
-            Robot.Instance.Battery.BatteryChanged += BatteryChanged;
+            this.challenge = new ChallengeFactory();
+            this.challenge.PublisherSubscriber.ConnectionStateChanged += PublisherSubscriber_ConnectionStateChanged;
+        }
+
+        private void PublisherSubscriber_ConnectionStateChanged(object? sender, bool e)
+        {
+            if(e == false)
+            {
+                if (manualDisconnect == true) manualDisconnect = false; return;
+                this.DisplayBottomMessage(MessageSeverity.Error, "Connection to MQTT broker lost.");
+                this.SetIpFieldsState(true, true, "Connect");
+            }
         }
 
         private void BatteryChanged(object? sender, BatteryEventArgs e)
@@ -37,13 +42,90 @@ namespace RobotClientWpf
             }
             else
             {
-                labelBattery.Content = $"Battery: {e.Voltage} V";
+                //labelBattery.Content = $"Battery: {e.Voltage} V";
             }
         }
 
         private void buttonBuzz_Click(object sender, RoutedEventArgs e)
         {
-            Robot.Instance.Buzzer.Beep(300, 500);
+            //Robot.Instance.Buzzer.Beep(300, 500);
+        }
+
+        private void btnConnectDisconnect_Click(object sender, RoutedEventArgs e)
+        {
+            Task.Run(delegate ()
+            {
+                this.ClearBottomMessage();
+                if (this.challenge.PublisherSubscriber.IsConnected)  // is connected => disconnect
+                {
+                    manualDisconnect = true;  // prevent wrong message
+                    this.challenge.PublisherSubscriber.Disconnect();
+                    this.DisplayBottomMessage(MessageSeverity.Success, "Disconnected from MQTT broker.");
+                    this.SetIpFieldsState(true, true, "Connect");
+                }
+                else // is not yet connected => connect
+                {
+                    this.SetIpFieldsState(false, false, "Connecting...");
+                    string ipAddress = UIAccessHelpers.GetTextboxText(tbIp);
+                    if (IPAddress.TryParse(ipAddress, out _))
+                    {
+                        var connectionSuccess = this.challenge.PublisherSubscriber.Connect(ipAddress);
+                        if (connectionSuccess)
+                        {
+                            this.DisplayBottomMessage(MessageSeverity.Success, "Successfully connected to MQTT broker.");
+                            this.SetIpFieldsState(false, true, "Disconnect");
+                        }
+                        else
+                        {
+                            this.DisplayBottomMessage(MessageSeverity.Error, $"Failed to connect to MQTT broker on address {ipAddress}.");
+                            this.SetIpFieldsState(true, true, "Connect");
+                        }
+                    }
+                    else
+                    {
+                        this.DisplayBottomMessage(MessageSeverity.Error, $"Unable to parse MQTT Broker IP address {ipAddress}.");
+                        this.SetIpFieldsState(true, true, "Connect");
+                    }
+                }
+            });
+        }
+
+        private void SetIpFieldsState(bool ipTextbox, bool connectDisconnectButton, string buttonText)
+        {
+            UIAccessHelpers.SetButtonState(btnConnectDisconnect, connectDisconnectButton);
+            UIAccessHelpers.SetTextboxState(tbIp, ipTextbox);
+            UIAccessHelpers.SetButtonContent(btnConnectDisconnect, buttonText);
+        }
+
+        public void DisplayBottomMessage(MessageSeverity severity, string message)
+        {
+            Brush col;
+            switch (severity)
+            {
+                case MessageSeverity.Success:
+                    col = Brushes.Green;
+                    break;
+                case MessageSeverity.Warning:
+                    col = Brushes.Orange;
+                    break;
+                case MessageSeverity.Error:
+                    col = Brushes.Red;
+                    break;
+                case MessageSeverity.Information:
+                    col = Brushes.Blue;
+                    break;
+                case MessageSeverity.Unknown:
+                default:
+                    col = Brushes.DarkGray;
+                    break;
+            }
+
+            UIAccessHelpers.SetTextblockTextAndForegroundColor(tbBottomMessage, message, col);
+        }
+
+        private void ClearBottomMessage()
+        {
+            this.DisplayBottomMessage(MessageSeverity.Information, "");
         }
     }
 }

ADIS_Csharp/RobotClientWpf/NLog.config

@@ -0,0 +1,27 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<nlog xmlns="http://www.nlog-project.org/schemas/NLog.xsd"
+      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+
+	<targets>
+		<target xsi:type="RichTextBox"
+				name="String"
+				layout="Layout"
+				height="Integer"
+				autoScroll="Boolean"
+				maxLines="Integer"
+				showMinimized="Boolean"
+				toolWindow="Boolean"
+				controlName="String"
+				formName="String"
+				width="Integer"
+				useDefaultRowColoringRules="Boolean">
+			<word-coloring backgroundColor="String" fontColor="String" ignoreCase="Boolean"
+						regex="String" style="Enum" text="String"
+						wholeWords="Boolean"/>
+			<!-- repeated -->
+			<row-coloring backgroundColor="String" condition="Condition" fontColor="String"
+					   style="Enum"/>
+			<!-- repeated -->
+		</target>
+	</targets>
+</nlog>

ADIS_Csharp/RobotClientWpf/RobotClientWpf.csproj

@@ -7,8 +7,22 @@
     <UseWPF>true</UseWPF>
   </PropertyGroup>
 
+  <ItemGroup>
+    <None Remove="Assets\cog.png" />
+    <None Remove="Assets\robot-industrial.png" />
+  </ItemGroup>
+
   <ItemGroup>
     <ProjectReference Include="..\RobotLib\RobotLib.csproj" />
   </ItemGroup>
 
+  <ItemGroup>
+    <Resource Include="Assets\cog.png">
+      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
+    </Resource>
+    <Resource Include="Assets\robot-industrial.png">
+      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
+    </Resource>
+  </ItemGroup>
+
 </Project>

ADIS_Csharp/RobotClientWpf/Utilities/UIAccessHelpers.cs

@@ -0,0 +1,103 @@
+using System;
+using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Controls.Primitives;
+using System.Windows.Media;
+
+namespace RobotClientWpf.Utilities
+{
+    public static class UIAccessHelpers
+    {
+        public static void SetButtonState(ButtonBase button, bool enabled)
+        {
+            if (!Application.Current.Dispatcher.CheckAccess())
+            {
+                Application.Current.Dispatcher.BeginInvoke(new Action(() =>
+                {
+                    SetButtonState(button, enabled);
+                }));
+            }
+            else
+            {
+                button.IsEnabled = enabled;
+            }
+        }
+        public static void SetButtonContent(ButtonBase button, string content)
+        {
+            if (!Application.Current.Dispatcher.CheckAccess())
+            {
+                Application.Current.Dispatcher.BeginInvoke(new Action(() =>
+                {
+                    SetButtonContent(button, content);
+                }));
+            }
+            else
+            {
+                button.Content = content;
+            }
+        }
+
+        public static string GetTextboxText(TextBox textBox)
+        {
+            string text = String.Empty;
+            if (!Application.Current.Dispatcher.CheckAccess())
+            {
+                Application.Current.Dispatcher.BeginInvoke(new Action(() =>
+                {
+                    text = GetTextboxText(textBox);
+                })).Wait();
+            }
+            else
+            {
+                text = textBox.Text;
+            }
+            return text;
+        }
+
+        public static void SetTextboxState(TextBoxBase textBox, bool enabled)
+        {
+            if (!Application.Current.Dispatcher.CheckAccess())
+            {
+                Application.Current.Dispatcher.BeginInvoke(new Action(() =>
+                {
+                    SetTextboxState(textBox, enabled);
+                }));
+            }
+            else
+            {
+                textBox.IsEnabled = enabled;
+            }
+        }
+
+        public static void SetTextboxText(TextBox textBox, string text)
+        {
+            if (!Application.Current.Dispatcher.CheckAccess())
+            {
+                Application.Current.Dispatcher.BeginInvoke(new Action(() =>
+                {
+                    SetTextboxText(textBox, text);
+                }));
+            }
+            else
+            {
+                textBox.Text = text;
+            }
+        }
+
+        public static void SetTextblockTextAndForegroundColor(TextBlock textBlock, string text, Brush foregroundColor)
+        {
+            if (!Application.Current.Dispatcher.CheckAccess())
+            {
+                Application.Current.Dispatcher.BeginInvoke(new Action(() =>
+                {
+                    SetTextblockTextAndForegroundColor(textBlock, text, foregroundColor);
+                }));
+            }
+            else
+            {
+                textBlock.Text = text;
+                textBlock.Foreground = foregroundColor;
+            }
+        }
+    }
+}

ADIS_Csharp/RobotClientWpf/Views/ConfigView.xaml

@@ -0,0 +1,13 @@
+<UserControl x:Class="RobotClientWpf.Views.ConfigView"
+             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:local="clr-namespace:RobotClientWpf.Views"
+             mc:Ignorable="d" 
+             d:DesignHeight="450" d:DesignWidth="800">
+    <Grid>
+        <Label Content="Config" HorizontalAlignment="Left" Margin="190,132,0,0" VerticalAlignment="Top"/>
+
+    </Grid>
+</UserControl>

ADIS_Csharp/RobotClientWpf/Views/ConfigView.xaml.cs

@@ -0,0 +1,28 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Data;
+using System.Windows.Documents;
+using System.Windows.Input;
+using System.Windows.Media;
+using System.Windows.Media.Imaging;
+using System.Windows.Navigation;
+using System.Windows.Shapes;
+
+namespace RobotClientWpf.Views
+{
+    /// <summary>
+    /// Interaction logic for ConfigView.xaml
+    /// </summary>
+    public partial class ConfigView : UserControl
+    {
+        public ConfigView()
+        {
+            InitializeComponent();
+        }
+    }
+}

ADIS_Csharp/RobotClientWpf/Views/MainView.xaml

@@ -0,0 +1,13 @@
+<UserControl x:Class="RobotClientWpf.Views.MainView"
+             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:local="clr-namespace:RobotClientWpf.Views"
+             mc:Ignorable="d" 
+             d:DesignHeight="450" d:DesignWidth="800">
+    <Grid>
+        <Label Content="Main" HorizontalAlignment="Left" Margin="443,192,0,0" VerticalAlignment="Top"/>
+
+    </Grid>
+</UserControl>

ADIS_Csharp/RobotClientWpf/Views/MainView.xaml.cs

@@ -0,0 +1,28 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Data;
+using System.Windows.Documents;
+using System.Windows.Input;
+using System.Windows.Media;
+using System.Windows.Media.Imaging;
+using System.Windows.Navigation;
+using System.Windows.Shapes;
+
+namespace RobotClientWpf.Views
+{
+    /// <summary>
+    /// Interaction logic for MainView.xaml
+    /// </summary>
+    public partial class MainView : UserControl
+    {
+        public MainView()
+        {
+            InitializeComponent();
+        }
+    }
+}

ADIS_Csharp/RobotLib/Communication/MqttPublisherSubscriber.cs

@@ -21,10 +21,28 @@ namespace RobotLib.Communication
         /// </summary>
         public event EventHandler<SubscribedMsgArrivedEventArgs> NewMessageArrived;
 
+        /// <summary>
+        /// Event to catch for the connection state to the broker.
+        /// </summary>
+        public event EventHandler<bool> ConnectionStateChanged;
+
         /// <summary>
         /// Connection state to the broker.
         /// </summary>
-        public bool IsConnected { get ; private set; }
+        public bool IsConnected
+        {
+            get { return _isConnected; }
+            private set
+            {
+                // generate event if the value has changed
+                if(_isConnected != value)
+                {
+                    this.ConnectionStateChanged?.Invoke(this, value);
+                }
+                _isConnected = value;
+            }
+        }
+        private bool _isConnected;
 
         private MqttPublisherSubscriber() 
         { }
@@ -63,6 +81,8 @@ namespace RobotLib.Communication
                 client.ConnectionClosed += Client_ConnectionClosed;
                 // generate a clientID and connect to Broker
                 string clientId = Guid.NewGuid().ToString();
+                try
+                {
                     if (String.IsNullOrEmpty(username) || String.IsNullOrEmpty(password))
                     {
                         client.Connect(clientId);
@@ -71,6 +91,12 @@ namespace RobotLib.Communication
                     {
                         client.Connect(clientId, username, password);
                     }
+                }
+                catch (Exception ex)
+                {
+                    log.Error(ex.Message);
+                }
+                
                 success = client.IsConnected;
                 log.Info($"Connecting done. Success = {success}");
             }
@@ -83,7 +109,12 @@ namespace RobotLib.Communication
             {
                 if (IsConnected == false) return;
 
+                try
+                {
                     client.Disconnect();
+                }
+                catch { }
+                
                 log.Info($"Disconnect was called.");
                 IsConnected = false;
             }