Architecture

AvalonDock v5.0.0 is built on a layered architecture that separates concerns between the layout model, visual controls, and extensibility points.

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Component Layers

┌─────────────────────────────────────────────────────┐
│                   Your Application                  │
├─────────────────────────────────────────────────────┤
│   AvalonDock.Mvvm.CommunityToolkit  (optional)      │
│   (ObservableObject-based classes)                  │
├─────────────────────────────────────────────────────┤
│   AvalonDock.Mvvm          │  AvalonDock.DI          │
│   (MVVM base classes)      │  (DI extensions)        │
├─────────────────────────────────────────────────────┤
│                    AvalonDock                        │
│   ┌─────────────┐  ┌──────────┐  ┌──────────────┐  │
│   │  Controls    │  │  Themes  │  │  Serializers │  │
│   │  (WPF UI)   │  │  (XAML)  │  │  (XML/JSON)  │  │
│   └──────┬──────┘  └────┬─────┘  └──────┬───────┘  │
│          │              │               │           │
│   ┌──────┴──────────────┴───────────────┴───────┐   │
│   │              Layout Model                    │   │
│   │   (LayoutRoot, LayoutPanel, LayoutContent)   │   │
│   └──────────────────┬──────────────────────────┘   │
├──────────────────────┼──────────────────────────────┤
│              AvalonDock.Core                        │
│   (Interfaces, Models, Base Classes)                │
└─────────────────────────────────────────────────────┘

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Package Architecture

AvalonDock v5.0.0 is distributed as multiple NuGet packages with clear dependency boundaries:

Core Packages

Package	Purpose
AvalonDock.Core	UI-agnostic interfaces, models, and serialization contracts. No WPF dependency.
AvalonDock	The main WPF docking library. Contains DockingManager, all controls, layout classes, and the default theme. Depends on AvalonDock.Core.

Extension Packages

Package	Purpose
AvalonDock.Mvvm	MVVM base classes: DockableBase, ToolboxBase, DockLayoutService, DockViewModels, and Factory. No external dependencies.
AvalonDock.Mvvm.CommunityToolkit	ObservableObject-based equivalents (ObservableDockableBase, ObservableToolboxBase, ObservableDocument, ObservableTool) with [ObservableProperty] and [RelayCommand] source generator support. Depends on CommunityToolkit.Mvvm.
AvalonDock.DependencyInjection	IServiceCollection extension methods for registering AvalonDock services.
AvalonDock.Serializer.Xml	XML-based layout serialization via XmlLayoutSerializer.
AvalonDock.Serializer.Json	JSON-based layout serialization via JsonLayoutSerializer.

Theme Packages

Each theme is a separate NuGet package so you only ship what you use:

Package	Variants
AvalonDock.Themes.Arc	ArcDarkTheme, ArcLightTheme
AvalonDock.Themes.VS2013	Vs2013DarkTheme, Vs2013LightTheme, Vs2013BlueTheme
AvalonDock.Themes.VS2010	Single theme
AvalonDock.Themes.Expression	Dark and Light variants
AvalonDock.Themes.Metro	Single theme
AvalonDock.Themes.Aero	Single theme

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Key Design Principles

1. Layout Model Drives the UI

AvalonDock uses a model-first architecture. The layout is represented as a tree of layout objects (LayoutRoot, LayoutPanel, LayoutDocumentPane, etc.). WPF controls are generated from this model, not the other way around. This separation enables:

• Layout serialization without UI dependency
• Programmatic layout manipulation
• MVVM-friendly design

2. Pluggable Layout Engine

The ILayoutEngine interface allows customization of how panels are measured, arranged, and resized. The DefaultLayoutEngine provides standard behavior, but you can implement your own for specialized layouts.

3. Theme Isolation

Themes are separate assemblies that provide XAML resource dictionaries. They can be swapped at runtime via the DockingManager.Theme property without any code changes.

4. Event-Driven Extensibility

AvalonDock exposes a rich set of events for every docking operation:

• AnchorableClosing / AnchorableClosed
• AnchorableHiding / AnchorableHidden
• DocumentClosing / DocumentClosed
• ContentDocked / ContentFloating
• LayoutFloatingWindowControlClosed

These events use cancellable patterns where appropriate, letting you intercept and prevent operations.

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The DockingManager

DockingManager is the root control and the central entry point for AvalonDock. It:

• Hosts the entire layout tree via its Layout property (of type LayoutRoot)
• Manages floating windows
• Handles drag-and-drop docking operations
• Applies themes
• Provides MVVM bindings for documents and anchorables

<avalonDock:DockingManager x:Name="dockManager">
    <avalonDock:DockingManager.Theme>
        <themes:ArcDarkTheme />
    </avalonDock:DockingManager.Theme>

    <avalonDock:LayoutRoot>
        <!-- Layout tree here -->
    </avalonDock:LayoutRoot>
</avalonDock:DockingManager>

In code-behind:

// Access the layout
LayoutRoot layout = dockManager.Layout;

// Change theme at runtime
dockManager.Theme = new ArcLightTheme();

// Find a specific anchorable
var explorer = layout.Descendents()
    .OfType<LayoutAnchorable>()
    .FirstOrDefault(a => a.ContentId == "explorer");