# Sandbox.UI.DockHost

Tabbed panel docking with nested splits. Registered content is owned until this host is deleted or transfers it.

- Kind: class
- Namespace: `Sandbox.UI`
- Assembly: `Sandbox.Engine`
- Inherits: [Sandbox.UI.Panel](/api/Sandbox.UI.Panel)

## Constructors

- [`DockHost`](/api/Sandbox.UI.DockHost/.ctor): Creates an empty docking workspace.

## Properties

- [`Items`](/api/Sandbox.UI.DockHost/Items): All registered panels, including closed panels.
- [`State`](/api/Sandbox.UI.DockHost/State): Saves tab order, selection and split proportions. Closed panels are omitted.

## Methods

- [`Activate`](/api/Sandbox.UI.DockHost/Activate): Selects an open panel without moving it.
- [`Close`](/api/Sandbox.UI.DockHost/Close): Closes a panel without deleting its content. Nonclosable panels are left open.
- [`Dock`](/api/Sandbox.UI.DockHost/Dock): Opens or moves a registered panel. Edge fractions describe the incoming panel's share.
- [`Find`](/api/Sandbox.UI.DockHost/Find): Finds a registered panel, including closed panels.
- [`IsOpen`](/api/Sandbox.UI.DockHost/IsOpen): Whether a registered panel is in the layout.
- [`OnDeleted`](/api/Sandbox.UI.DockHost/OnDeleted)
- [`Register`](/api/Sandbox.UI.DockHost/Register): Registers content, initially closed. A panel instance can belong to only one registration.
- [`RestoreState`](/api/Sandbox.UI.DockHost/RestoreState): Restores a valid layout atomically. Open nonclosable panels must remain present.
- [`Tick`](/api/Sandbox.UI.DockHost/Tick)