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.

Figure 3.1. Layout modules type hierarchy

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.NET. 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 LayoutModulesForm shows how to use the layout modules in an application context.