A layout module serves as a convenient means for interactively configuring and launching a yFiles layout algorithm. Layout modules inherit from abstract classes LayoutModule and YModule, respectively.

Layout modules inherit from abstract classes LayoutModule and YModule, respectively.

Figure 3.1. Layout modules type hierarchy

The OptionHandler that is used with an actual layout module can be obtained via the Handler property defined by YModule. The following methods from LayoutModule can be used to invoke a yFiles layout algorithm:

// Invoking the layout algorithm.
void Start(ILookup newContext)
void Start(LayoutGraph layoutGraph)

The Start method that takes an ILookup as parameter allows to invoke a layout algorithm when there is no LayoutGraph object readily available. For example, to use an IGraph instance a setup similar to Example 3.5, “Using an IGraph for layout invocation” can be used.

Note that when layout morphing is enabled via the layout module's LayoutMorphingEnabled property, a GraphControl is expected being available in the ILookup, too. It is used to determine the actual canvas where morphing should take place.

// 'myGraph' is of type yWorks.yFiles.UI.Model.IGraph.
// 'myGraphControl' is of type yWorks.yFiles.UI.GraphControl.

// Setting up an ILookup object.
DictionaryLookup context = new DictionaryLookup();
context.Put(typeof (IGraph), myGraph);
// Enables layout morphing.
context.Put(typeof (GraphControl), myGraphControl);

// Invoking a layout algorithm via its layout module.
someLayoutModule.LayoutMorphingEnabled = true;
someLayoutModule.Start(context);

Table 3.1, “Layout modules” lists the layout modules available with yFiles WPF. Similar to setting up layout morphing functionality as described above, some of the layout algorithms encapsulated by a layout module expect a CanvasControl object being available in the ILookup.

Tutorial demo application LayoutModulesWindow shows how to use the layout modules in an application context.