Reference transformer for grapher

For a simple example of how a reference transformer is used, consider the boundingBox method. This abstract method of the IlvGraphModel class is implemented in the IlvGrapherAdapter . To compute the bounding box, it calls the IlvGrapher method of the graphic object that it receives as an argument. However, it does not handle zoomable objects and nonzoomable objects in the same way.

If the graphic object is zoomable, the boundingBox boundingBox(Object nodeOrLink) method of the IlvGrapherAdapter returns the bounding box in manager coordinates by calling IlvGraphic.boundingBox(null) .

If the graphic object is nonzoomable, the boundingBox boundingBox(Object nodeOrLink) method computes the bounding box according to the reference transformer and returns a rectangle obtained by applying the inverse transformation to this rectangle, see the inverse IlvTransformer.inverse(IlvRect rect) method.

The geometry of the IlvGrapher is computed in such a manner that the resulting drawing inside an IlvManagerView using the reference transformer will look fine.

Optionally, an IlvManagerView can be specified as a reference view for the IlvGrapherAdapter. If a reference view is specified, its current transformer (at the moment when the layout is started) is automatically used as the reference transformer. Usually, applications use the same manager view that is used for the display of the IlvGrapher as the reference view (but this is not mandatory).

To specify the reference view, use the following method:

void setReferenceView(IlvManagerView view)  

To get the current reference view, use the method:

IlvManagerView getReferenceView()  

If no view has been specified as the reference view, the method returns null .