developerWorks: Create an Eclipse-based application using the Graphical Editing Framework

“The article walks you through the steps for using GEF. Rather
than finishing each step in its entirety, we’ll use a subset of
your application’s model and get that working first. For example,
we might initially ignore connections, or focus on just a subset of
the types of graphical elements in your application.

“GEF assumes that you have a model that you would like to
display and edit graphically. To do this, GEF provides viewers (of
the type EditPartViewer) that can be used anywhere in the Eclipse
workbench. Like JFace viewers, GEF viewers are adapters on an SWT
Control. But the similarity stops there. GEF viewers are based on a
model-view-controller (MVC) architecture.

“The controllers bridge the view and model. Each controller, or
EditPart as they are called here, is responsible both for mapping
the model to its view, and for making changes to the model. The
EditPart also observes the model, and updates the view to reflect
changes in the model’s state. EditParts are the objects with which
the user interacts. EditParts are covered in more detail
later…”

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