With the first and second release of the .Net WPF library (WPF 3.0 and 3.5) there is no API provided for creating an MDI (Multiple document interface) or TDI (Tabbed Document Interface). This is where docking control tries to fill the gab by providing a WPF control library that provides a Tabbed Document Interface for your application.

View example 1

With Docking control, you declare the content of each item as a Uri to a resource, similar like a Frame uses Uri's to resources. This allows you to keep your xaml nicely crisp and clean by splitting it up into reusable parts. The Uri, together with a title and icon make up a ToolFrameItem, which is the smallest building block of Docking control. A set of these items is managed by a ToolFrame which is the object that resembles a TabControl.

View example 2

This is a somewhat more elaborate example . The window has a DockPanel with a menu at the top. This menu can be used to toggle the different tool windows on and off. Notice that there is no code behind required to perform this. All it takes are 2 styles containing some bindings which set up the content of the menu items from within the xaml file. The rest of the DockPanel is filled with the docking control. It defines 4 ToolFrame objects, which divide the available space in 4 regions: a left (upper and lower), right side and a center, which is the last ToolFrame and fills the remainder of the space.

Each ToolFrame can have a header containing the title of the currently selected ToolFrameItem and some buttons which control various properties (you can add your own buttons or replace the default icons through a template). The ToolFrame displays a tab strip when it manages more than 1 ToolFrameItem. The location and appearance of this tabstrip can also be controlled through various properties and templates.

All properties can easily be controlled from within your favorite designer. Adding ToolFrames and Items, setting the properties or visually resizing them is all supported by the control. You never have to leave the environment and type xaml.

All the ToolFrames on a docking control can easily be collapsed to the border of the control, just like in Visual studio. There is a button on the default template of the header for the ToolFrames which switches the location of the ToolFrame between 'Collapsed' or 'pinned'. To display these collapsed items, the user simply needs to hover the mouse over the border button, the collapsed ToolFrame will become visible in a popup border object. It collapses automatically after a short delay when the mouse leaves the popup.

The location to where the ToolFrame is collapsed is automatically determined based on it's relative position as seen by the user. This becomes important as ToolFrames can be placed relative to another ToolFrame. See Drag and Drop support for more info on this.

The docking control provides Drag and drop support right out of the box. There is no coding or modifications of any sort required to provide the possibility to the user for rearranging the layout of the ToolFrames.

A ToolFrame can be made floating simply by dragging it from the docking control with it's header or by using a command (notice that you can change to all possible locations from every single location, unlike most TDI libraries, for instance, try initiating a drag while the ToolFrame is in the popup border). Once it is floating, it can be dragged around and dropped at another location on the same docking control. Whenever a new drag operation starts, the docking control displays an overlay that indicates all the possible drop zones. A ToolFrame can be dropped at one of the outer drop zones to place the item on the outside, it can be dropped relative to another ToolFrame or the tab items can be merged into another ToolFrame. This behavior is also very similar as found in the Visual studio development environment.

Switching between the active item on the docking control, which determins where the keyboard focus is, is also provided. You can choose which key triggers a switch (usefull for xbap applications) and wether a selection window is shown. This window can be cusomtized to contain any information in any type of style that you prefer.

The control also provides a very powerfull streaming functionality for storing different layouts. It is able to store and retrieve multiple configurations simultaneously. This allows the user to dynamically change the intire layout in one operation.

Docking control can be used in XBAP applications, instantaneously providing a rich user interface to any web application developed with WPF. Even dragging and floating windows are fully supported, also in partial trust applications. This is because the control automatically detects if it is running in a browser host and automatically switches it's internal mode. The examples section has some demo applications you can play with directly from inside your browser.  The same applications are also availabe as normal click-once executables.