MainWindow.xaml

<Window x:Class="WPFBase.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:WPFBase"
        xmlns:avalon="https://github.com/Dirkster99/AvalonDock"
        mc:Ignorable="d"
        Title="{Binding ApplicationTitle}" 
        Height="700" Width="1200"
        WindowStartupLocation="CenterScreen"
        Background="{DynamicResource BackgroundColorBrush}"
        AllowDrop="True"
        Drop="Window_Drop"
        DragOver="Window_DragOver">
    
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="*"/>
            <RowDefinition Height="Auto"/>
        </Grid.RowDefinitions>
        
        <!-- Menu Bar -->
        <Menu Grid.Row="0" Background="{DynamicResource BackgroundColorBrush}">
            <MenuItem Header="_File">
                <MenuItem Header="_New" Command="{Binding NewCommand}" InputGestureText="Ctrl+N"/>
                <MenuItem Header="_Open" Command="{Binding OpenCommand}" InputGestureText="Ctrl+O"/>
                <MenuItem Header="_Save" Command="{Binding SaveCommand}" InputGestureText="Ctrl+S"/>
                <MenuItem Header="Save _All" Command="{Binding SaveAllCommand}" InputGestureText="Ctrl+Shift+S"/>
                <Separator/>
                <MenuItem Header="Recent Files" x:Name="RecentFilesMenuItem">
                    <MenuItem.Style>
                        <Style TargetType="MenuItem">
                            <Setter Property="Visibility" Value="Visible"/>
                            <Style.Triggers>
                                <DataTrigger Binding="{Binding RecentFiles.Count}" Value="0">
                                    <Setter Property="Visibility" Value="Collapsed"/>
                                </DataTrigger>
                            </Style.Triggers>
                        </Style>
                    </MenuItem.Style>
                    <MenuItem.ItemsSource>
                        <CompositeCollection>
                            <CollectionContainer Collection="{Binding Source={x:Reference RecentFilesMenuItem}, Path=DataContext.RecentFiles}"/>
                            <Separator/>
                            <MenuItem Header="Clear Recent Files" Command="{Binding ClearRecentFilesCommand}"/>
                        </CompositeCollection>
                    </MenuItem.ItemsSource>
                    <MenuItem.ItemContainerStyle>
                        <Style TargetType="MenuItem">
                            <Setter Property="Header" Value="{Binding DisplayName}"/>
                            <Setter Property="Command" Value="{Binding DataContext.OpenRecentFileCommand, RelativeSource={RelativeSource AncestorType=Window}}"/>
                            <Setter Property="CommandParameter" Value="{Binding FilePath}"/>
                            <Setter Property="ToolTip" Value="{Binding FilePath}"/>
                        </Style>
                    </MenuItem.ItemContainerStyle>
                </MenuItem>
                <Separator/>
                <MenuItem Header="_Close" Command="{Binding CloseCommand}"/>
                <MenuItem Header="Close All" Command="{Binding CloseAllCommand}"/>
                <Separator/>
                <MenuItem Header="E_xit" Command="{Binding ExitCommand}" InputGestureText="Alt+F4"/>
            </MenuItem>
            <MenuItem Header="_Edit">
                <MenuItem Header="_Undo" InputGestureText="Ctrl+Z"/>
                <MenuItem Header="_Redo" InputGestureText="Ctrl+Y"/>
                <Separator/>
                <MenuItem Header="Cu_t" InputGestureText="Ctrl+X"/>
                <MenuItem Header="_Copy" InputGestureText="Ctrl+C"/>
                <MenuItem Header="_Paste" InputGestureText="Ctrl+V"/>
            </MenuItem>
            <MenuItem Header="_View">
                <MenuItem Header="_Solution Explorer" Command="{Binding ShowSolutionExplorerCommand}"/>
                <MenuItem Header="_Properties" Command="{Binding ShowPropertiesCommand}"/>
                <MenuItem Header="_Output" Command="{Binding ShowOutputCommand}"/>
                <MenuItem Header="_Error List" Command="{Binding ShowErrorListCommand}"/>
                <Separator/>
                <MenuItem Header="Toggle _Theme" Command="{Binding ToggleThemeCommand}"/>
                <Separator/>
                <MenuItem Header="_Reset Layout" Command="{Binding ResetLayoutCommand}"/>
                <MenuItem Header="_Save Layout" Command="{Binding SaveLayoutCommand}"/>
                <MenuItem Header="_Load Layout" Command="{Binding LoadLayoutCommand}"/>
            </MenuItem>
            <MenuItem Header="_Window">
                <MenuItem Header="_Float All" Command="{Binding FloatAllCommand}"/>
                <MenuItem Header="_Dock All" Command="{Binding DockAllCommand}"/>
                <Separator/>
                <MenuItem Header="_Close All Documents" Command="{Binding CloseAllDocumentsCommand}"/>
            </MenuItem>
            <MenuItem Header="_Help">
                <MenuItem Header="_About" Command="{Binding ShowAboutCommand}"/>
                <MenuItem Header="_Test Exception" Command="{Binding TestExceptionCommand}"/>
            </MenuItem>
        </Menu>
        
        <!-- Toolbar -->
        <ToolBar Grid.Row="1" Background="{DynamicResource BackgroundColorBrush}">
            <Button Command="{Binding NewCommand}" ToolTip="New (Ctrl+N)" Padding="5" Margin="2">
                <TextBlock Text="📄 New" />
            </Button>
            <Button Command="{Binding OpenCommand}" ToolTip="Open (Ctrl+O)" Padding="5" Margin="2">
                <TextBlock Text="📁 Open" />
            </Button>
            <Button Command="{Binding SaveCommand}" ToolTip="Save (Ctrl+S)" Padding="5" Margin="2">
                <TextBlock Text="💾 Save" />
            </Button>
            <Separator/>
            <Button Command="{Binding UndoCommand}" ToolTip="Undo (Ctrl+Z)" Padding="5" Margin="2">
                <TextBlock Text="↶ Undo" />
            </Button>
            <Button Command="{Binding RedoCommand}" ToolTip="Redo (Ctrl+Y)" Padding="5" Margin="2">
                <TextBlock Text="↷ Redo" />
            </Button>
            <Separator/>
            <Button Command="{Binding ToggleThemeCommand}" ToolTip="Toggle Theme" Padding="5" Margin="2">
                <TextBlock Text="🌓 Theme" />
            </Button>
        </ToolBar>
        
        <!-- AvalonDock Docking Manager -->
        <avalon:DockingManager x:Name="DockManager" 
                              Grid.Row="2"
                              DocumentsSource="{Binding Documents}"
                              AnchorablesSource="{Binding Tools}"
                              ActiveContent="{Binding ActiveDocument, Mode=TwoWay}">
            
            <!-- Theme -->
            <avalon:DockingManager.Theme>
                <avalon:Vs2013LightTheme/>
            </avalon:DockingManager.Theme>
            
            <!-- Layout Update Strategy -->
            <avalon:DockingManager.LayoutUpdateStrategy>
                <local:LayoutInitializer/>
            </avalon:DockingManager.LayoutUpdateStrategy>
            
            <!-- Default Layout -->
            <avalon:LayoutRoot>
                <avalon:LayoutPanel Orientation="Horizontal">
                    
                    <!-- Left Tools -->
                    <avalon:LayoutAnchorablePane Name="LeftTools" DockWidth="250">
                    </avalon:LayoutAnchorablePane>
                    
                    <!-- Center Documents and Bottom Tools -->
                    <avalon:LayoutPanel Orientation="Vertical">
                        
                        <!-- Documents -->
                        <avalon:LayoutDocumentPane/>
                        
                        <!-- Bottom Tools -->
                        <avalon:LayoutAnchorablePane Name="BottomTools" DockHeight="150">
                        </avalon:LayoutAnchorablePane>
                        
                    </avalon:LayoutPanel>
                    
                    <!-- Right Tools -->
                    <avalon:LayoutAnchorablePane Name="RightTools" DockWidth="250">
                    </avalon:LayoutAnchorablePane>
                    
                </avalon:LayoutPanel>
            </avalon:LayoutRoot>
            
            <!-- Document Header Template -->
            <avalon:DockingManager.DocumentHeaderTemplate>
                <DataTemplate>
                    <StackPanel Orientation="Horizontal">
                        <TextBlock Text="{Binding Title}" VerticalAlignment="Center"/>
                        <TextBlock Text="{Binding Content.DataContext.IsDirty, 
                                  Converter={StaticResource DirtyStateToSymbolConverter}}" 
                                  Margin="2,0,0,0" VerticalAlignment="Center"
                                  Foreground="Red" FontWeight="Bold"/>
                    </StackPanel>
                </DataTemplate>
            </avalon:DockingManager.DocumentHeaderTemplate>
            
            <!-- Anchorable Header Template -->
            <avalon:DockingManager.AnchorableHeaderTemplate>
                <DataTemplate>
                    <TextBlock Text="{Binding Title}" VerticalAlignment="Center"/>
                </DataTemplate>
            </avalon:DockingManager.AnchorableHeaderTemplate>
            
        </avalon:DockingManager>
        
        <!-- Status Bar -->
        <StatusBar Grid.Row="3" Background="{DynamicResource BackgroundColorBrush}">
            <StatusBarItem>
                <TextBlock Text="{Binding StatusText}" Foreground="{DynamicResource ForegroundColorBrush}"/>
            </StatusBarItem>
            <Separator/>
            <StatusBarItem>
                <ProgressBar Width="100" Height="16" 
                           Value="{Binding ProgressValue}" 
                           Visibility="{Binding ProgressValue, Converter={StaticResource DoubleToVisibilityConverter}}"
                           Foreground="{Binding ProgressValue, Converter={StaticResource ProgressToBrushConverter}}"/>
            </StatusBarItem>
            <Separator/>
            <StatusBarItem>
                <TextBlock Text="{Binding DocumentCount, Converter={StaticResource DocumentCountConverter}}" 
                         Foreground="{DynamicResource ForegroundColorBrush}"/>
            </StatusBarItem>
            <Separator/>
            <StatusBarItem HorizontalAlignment="Right">
                <StackPanel Orientation="Horizontal">
                    <TextBlock Text="Theme: " Foreground="{DynamicResource ForegroundColorBrush}"/>
                    <TextBlock Text="{Binding CurrentThemeName, Converter={StaticResource ThemeNameConverter}}" 
                             Foreground="{DynamicResource PrimaryColorBrush}"
                             FontWeight="Bold"/>
                </StackPanel>
            </StatusBarItem>
        </StatusBar>
    </Grid>
</Window>