Berth.Core 0.1.1

Berth

Docking library for Avalonia modelled on IntelliJ IDEA: six fixed tool-window slots (3 sides × 2 groups), five display modes (dock pinned / dock unpinned / undock / float / window), a document area as a tree of splits with tab groups, floating windows and layout save/restore. Deliberately not free-form docking — strict rules give an enumerable state space and, with it, reliability: behaviour is defined by written specs, and every normative clause is covered by a test carrying the same id.

<img src="https://raw.githubusercontent.com/xoma-zver/Berth/master/docs/assets/berth-hero-light.png" width="720" alt="Berth layout model: icon stripes, docked tool windows, panel tabs, the document area with a split, and a floating overlay above the layout">

Packages

• Berth.Core — the layout model and operations: pure, serializable state and pure transitions. No UI-framework dependency; namespace Berth.
• Berth.Avalonia — the Avalonia controls that materialize the model. Depends on Berth.Core; namespace Berth.Controls.

Install the controls (Berth.Core comes transitively):

dotnet add package Berth.Avalonia

Highlights

• Tool windows — six slots, five modes with per-layer eviction, focus-driven auto-hide, stripes with a quick-access “⋯” list, two-level menus, application-bound activation shortcuts; side and pair geometry in fractions — pixels never enter the core.
• Document area — an n-ary tree of splits with tab groups, normalized to canonical form; document windows; one tree model shared with tool-window content, so tabs travel between a panel and the dock area by the same commands.
• Floating layer — real OS windows on the desktop, pseudo-windows in the browser overlay; the stored mode never degrades, only the effective presentation (CanFloat/CanUseWindowed).
• Drag-and-drop — a thin layer over core commands (every gesture is also reachable from menus and code), with ghost miniatures, drop-zone previews and a live tab-strip reorder preview.
• Persistence — versioned JSON, Apply with a fix report, sleeping states for unregistered content, layout reset that keeps open documents.
• Composition — a fluent builder in the core and declarative AXAML definitions (BerthWorkspace.Definition).

Minimal use

Compose a layout with the fluent builder and hand its parts to BerthWorkspace:

var composition = new LayoutCompositionBuilder()
    .AddToolWindow("project", "Project", w => w
        .Slot(ToolWindowSide.Left, ToolWindowGroup.Primary)
        .Content(_ => new TextBlock { Text = "Project tree" }))
    .AddDockContent(
        id => id.StartsWith("doc:", StringComparison.Ordinal),
        id => new TextBox { Text = $"// {id[4..]}", AcceptsReturn = true })
    .Open("project")
    .OpenDocument("doc:README.md")
    .Build();

var workspace = new BerthWorkspace
{
    Registry = composition.Registry,
    Lifecycle = composition.Lifecycle,
    State = composition.State, // bindable two-way; gestures assign the command result back
};

Or declare the default layout in AXAML via BerthWorkspace.Definition (BerthLayoutDefinition). Persistence is application policy over the core bricks (LayoutPersistence, Apply with a fix report, ResetToDefaults, FloatingBoundsValidation).

Platforms

Desktop (Windows, macOS, Linux) and browser (WebAssembly; floating panels and document windows become overlay pseudo-windows). Mobile targets build best-effort; touch docking behaviour is unspecified.

Status

Pre-1.0 (0.1.x): v1 functionality is complete; the public API and the persistence schema may still move.

Links

• Repository, docs and specs: https://github.com/xoma-zver/Berth
• Getting started, behavioural specs (docs/spec/) and ADRs (docs/adr/) live in the repo.

Licensed under the MIT License.