Added running log panel in the below screen

Examples/Nodify.Calculator/ApplicationViewModel.cs

@@ -4,6 +4,7 @@ using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using System.Threading.Tasks;
 using System.Windows;
 using System.Windows.Input;
 using System.Windows.Shapes;
@@ -25,6 +26,8 @@ namespace Nodify.Calculator
                 _ => Editors.Count > 0 && SelectedEditor != null);
             RunFlowCommand = new DelegateCommand(() =>
             {
+                if (LogPanel.IsRunning) return;
+
                 Executor ex = new Executor(Editors.First());
                 var result = ex.PerformPreCheck();
                 if (!string.IsNullOrEmpty(result))
@@ -33,8 +36,21 @@ namespace Nodify.Calculator
                 }
                 else
                 {
-                    FlowRunner runner = new FlowRunner(ex);
+                    LogPanel.LogEntries.Clear();
-                    runner.ShowDialog();
+                    LogPanel.IsOpen = true;
+                    LogPanel.IsRunning = true;
+                    ex.OnLogMe += LogPanel.WriteLog;
+                    Task.Run(() =>
+                    {
+                        try
+                        {
+                            ex.Execute();
+                        }
+                        finally
+                        {
+                            Application.Current?.Dispatcher.Invoke(() => LogPanel.IsRunning = false);
+                        }
+                    });
                 }
             });
             SaveFileCommand = new DelegateCommand(() =>
@@ -127,5 +143,7 @@ namespace Nodify.Calculator
             get => _autoSelectNewEditor;
             set => SetProperty(ref _autoSelectNewEditor, value);
         }
+
+        public LogPanelViewModel LogPanel { get; } = new LogPanelViewModel();
     }
 }

Examples/Nodify.Calculator/LogPanelViewModel.cs

@@ -0,0 +1,76 @@
+using System;
+using System.Collections.ObjectModel;
+using System.Windows.Media;
+
+namespace Nodify.Calculator
+{
+    public class LogEntry
+    {
+        public string Timestamp { get; set; }
+        public string Level { get; set; }
+        public string Message { get; set; }
+        public Brush Color { get; set; }
+    }
+
+    public class LogPanelViewModel : ObservableObject
+    {
+        private bool _isOpen;
+        public bool IsOpen
+        {
+            get => _isOpen;
+            set => SetProperty(ref _isOpen, value);
+        }
+
+        private bool _isRunning;
+        public bool IsRunning
+        {
+            get => _isRunning;
+            set => SetProperty(ref _isRunning, value);
+        }
+
+        public ObservableCollection<LogEntry> LogEntries { get; } = new ObservableCollection<LogEntry>();
+
+        public INodifyCommand ClearLogsCommand { get; }
+        public INodifyCommand ClosePanelCommand { get; }
+
+        public LogPanelViewModel()
+        {
+            ClearLogsCommand = new DelegateCommand(() => LogEntries.Clear());
+            ClosePanelCommand = new DelegateCommand(() => IsOpen = false);
+        }
+
+        public void WriteLog(string message, logType logtype = logType.Information)
+        {
+            Brush color;
+            switch (logtype)
+            {
+                case logType.Warning:
+                    color = Brushes.Orange;
+                    break;
+                case logType.Error:
+                    color = Brushes.OrangeRed;
+                    break;
+                default:
+                    color = Brushes.White;
+                    break;
+            }
+
+            var entry = new LogEntry
+            {
+                Timestamp = DateTime.Now.ToString("HH:mm:ss"),
+                Level = logtype.ToString(),
+                Message = message,
+                Color = color
+            };
+
+            if (System.Windows.Application.Current?.Dispatcher.CheckAccess() == true)
+            {
+                LogEntries.Add(entry);
+            }
+            else
+            {
+                System.Windows.Application.Current?.Dispatcher.Invoke(() => LogEntries.Add(entry));
+            }
+        }
+    }
+}

Examples/Nodify.Calculator/MainWindow.xaml

@@ -51,7 +51,14 @@
     </Window.Resources>
     
     <Grid>
-        <shared:TabControlEx ItemsSource="{Binding Editors}"
+        <Grid.RowDefinitions>
+            <RowDefinition Height="*" />
+            <RowDefinition Height="Auto" />
+            <RowDefinition Height="Auto" MinHeight="0" />
+        </Grid.RowDefinitions>
+
+        <shared:TabControlEx Grid.Row="0"
+                             ItemsSource="{Binding Editors}"
                              SelectedItem="{Binding SelectedEditor}" 
                              AddTabCommand="{Binding AddEditorCommand}"
                              AutoScrollToEnd="{Binding AutoSelectNewEditor}">
@@ -70,7 +77,110 @@
             </shared:TabControlEx.ItemContainerStyle>
         </shared:TabControlEx>
 
-        <Expander Header="Click to hide/show"
+        <!-- Log Panel -->
+        <Border Grid.Row="1" Height="3" Cursor="SizeNS"
+                Background="Transparent">
+            <Border.Style>
+                <Style TargetType="Border">
+                    <Style.Triggers>
+                        <DataTrigger Binding="{Binding LogPanel.IsOpen}" Value="False">
+                            <Setter Property="Visibility" Value="Collapsed" />
+                        </DataTrigger>
+                    </Style.Triggers>
+                </Style>
+            </Border.Style>
+            <GridSplitter HorizontalAlignment="Stretch"
+                          VerticalAlignment="Stretch"
+                          Background="#FF3F3F46"
+                          ResizeBehavior="PreviousAndNext"
+                          ResizeDirection="Rows" />
+        </Border>
+
+        <Border Grid.Row="2" Background="#FF1E1E1E" BorderBrush="#FF3F3F46" BorderThickness="0,1,0,0">
+            <Border.Style>
+                <Style TargetType="Border">
+                    <Setter Property="Height" Value="180" />
+                    <Style.Triggers>
+                        <DataTrigger Binding="{Binding LogPanel.IsOpen}" Value="False">
+                            <Setter Property="Visibility" Value="Collapsed" />
+                            <Setter Property="Height" Value="0" />
+                        </DataTrigger>
+                    </Style.Triggers>
+                </Style>
+            </Border.Style>
+            <Grid>
+                <Grid.RowDefinitions>
+                    <RowDefinition Height="28" />
+                    <RowDefinition Height="*" />
+                </Grid.RowDefinitions>
+
+                <!-- Header bar -->
+                <Border Grid.Row="0" Background="#FF2D2D30" BorderBrush="#FF3F3F46" BorderThickness="0,0,0,1">
+                    <DockPanel Margin="8,0">
+                        <TextBlock Text="⚡ Output" VerticalAlignment="Center" Foreground="#FFDCDCDC" FontWeight="SemiBold" FontSize="12" />
+                        <TextBlock VerticalAlignment="Center" Margin="10,0,0,0" Foreground="#FF888888" FontSize="11">
+                            <TextBlock.Style>
+                                <Style TargetType="TextBlock">
+                                    <Setter Property="Text" Value="" />
+                                    <Style.Triggers>
+                                        <DataTrigger Binding="{Binding LogPanel.IsRunning}" Value="True">
+                                            <Setter Property="Text" Value="● Running..." />
+                                            <Setter Property="Foreground" Value="#FF4EC9B0" />
+                                        </DataTrigger>
+                                    </Style.Triggers>
+                                </Style>
+                            </TextBlock.Style>
+                        </TextBlock>
+                        <StackPanel DockPanel.Dock="Right" Orientation="Horizontal" HorizontalAlignment="Right">
+                            <Button Content="🗑 Clear" Command="{Binding LogPanel.ClearLogsCommand}"
+                                    Background="Transparent" Foreground="#FFAAAAAA" BorderThickness="0"
+                                    Padding="6,2" FontSize="11" Cursor="Hand" Margin="0,0,4,0" />
+                            <Button Content="✕" Command="{Binding LogPanel.ClosePanelCommand}"
+                                    Background="Transparent" Foreground="#FFAAAAAA" BorderThickness="0"
+                                    Padding="6,2" FontSize="11" Cursor="Hand" />
+                        </StackPanel>
+                    </DockPanel>
+                </Border>
+
+                <!-- Log entries -->
+                <ListBox Grid.Row="1" x:Name="LogListBox"
+                         ItemsSource="{Binding LogPanel.LogEntries}"
+                         Background="#FF1E1E1E" BorderThickness="0"
+                         ScrollViewer.HorizontalScrollBarVisibility="Disabled"
+                         ScrollViewer.VerticalScrollBarVisibility="Auto"
+                         VirtualizingStackPanel.IsVirtualizing="True"
+                         FontFamily="Consolas" FontSize="12">
+                    <ListBox.ItemContainerStyle>
+                        <Style TargetType="ListBoxItem">
+                            <Setter Property="Padding" Value="8,1" />
+                            <Setter Property="Background" Value="Transparent" />
+                            <Setter Property="BorderThickness" Value="0" />
+                            <Setter Property="Focusable" Value="False" />
+                            <Setter Property="Template">
+                                <Setter.Value>
+                                    <ControlTemplate TargetType="ListBoxItem">
+                                        <Border Padding="{TemplateBinding Padding}" Background="{TemplateBinding Background}">
+                                            <ContentPresenter />
+                                        </Border>
+                                    </ControlTemplate>
+                                </Setter.Value>
+                            </Setter>
+                        </Style>
+                    </ListBox.ItemContainerStyle>
+                    <ListBox.ItemTemplate>
+                        <DataTemplate>
+                            <TextBlock TextWrapping="NoWrap">
+                                <Run Text="{Binding Timestamp, Mode=OneTime}" Foreground="#FF608B4E" />
+                                <Run Text=" " />
+                                <Run Text="{Binding Message, Mode=OneTime}" Foreground="{Binding Color, Mode=OneTime}" />
+                            </TextBlock>
+                        </DataTemplate>
+                    </ListBox.ItemTemplate>
+                </ListBox>
+            </Grid>
+        </Border>
+
+        <Expander Grid.Row="0" Header="Click to hide/show"
                   IsExpanded="False"
                   Margin="10"
                   HorizontalAlignment="Left"

Examples/Nodify.Calculator/MainWindow.xaml.cs

@@ -1,7 +1,9 @@
 using Nodify.Interactivity;
+using System.Collections.Specialized;
 using System.ComponentModel;
 using System.Linq;
 using System.Windows;
+using System.Windows.Controls;
 using System.Windows.Input;
 
 namespace Nodify.Calculator
@@ -20,6 +22,23 @@ namespace Nodify.Calculator
                     (KeyboardFocusChangedEventHandler)OnPreviewGotKeyboardFocus);
 
             Closing += MainWindow_Closing;
+
+            // Auto-scroll log list to bottom when new entries are added
+            Loaded += (_, __) =>
+            {
+                if (DataContext is ApplicationViewModel appVm)
+                {
+                    ((INotifyCollectionChanged)appVm.LogPanel.LogEntries).CollectionChanged += (s, e) =>
+                    {
+                        if (e.Action == NotifyCollectionChangedAction.Add)
+                        {
+                            var listBox = FindName("LogListBox") as ListBox;
+                            if (listBox != null && appVm.LogPanel.LogEntries.Count > 0)
+                                listBox.ScrollIntoView(appVm.LogPanel.LogEntries[appVm.LogPanel.LogEntries.Count - 1]);
+                        }
+                    };
+                }
+            };
         }
 
         private void MainWindow_Closing(object sender, CancelEventArgs e)