Graphical Editing Framework - Eclipse Modeling Project: A Domain-Specific Language Toolkit - page 327

EditPart
Factory

Graphical Viewer

Model EditParts Figures

Figure 9-9 GEF EditPartFactory

Following is code from the GEF Logic Diagram example's LogicEditor class,
showing how its GraphicalViewer is set up. Note that I have removed config-
uration code for elements not discussed (such as zoom and action configuration).

protected void configureGraphicalViewer() {
super .configureGraphicalViewer();
ScrollingGraphicalViewer viewer =
(ScrollingGraphicalViewer)getGraphicalViewer();
ScalableFreeformRootEditPart root = new
ScalableFreeformRootEditPart();
viewer.setRootEditPart(root);
viewer.setEditPartFactory( new GraphicalPartFactory());

}

The contents are set in the LogicEditor's setContents() method:

getGraphicalViewer().setContents(getLogicDiagram());

Looking at the logic diagram's implementation of EditPartFactory , you
can get a feel for how EditPart s are created for corresponding model objects.

public class GraphicalPartFactory implements EditPartFactory {

public EditPart createEditPart(EditPart context, Object model) {
EditPart child = null ;

if (model instanceof LogicFlowContainer)
child = new LogicFlowContainerEditPart();
else if (model instanceof Wire)