The Diagram Editor is a tool for creating, managing and maintaining graphs as diagrams. With a Diagram Editor you can view and edit graphs as well as make or view explosions and decompositions between several graphs. Basically, except for the notation of the selected modeling language, the tool always looks the same. For example, in Figure 4-1 we have two Diagram Editors open, containing different types of graph, i.e. graphs from different languages.

The Diagram Editor window (Figure 4-2) consists of five parts: menu bar, toolbar area, drawing area, sidebar and status bar.

The toolbar area can show up to three toolbars: action tools, object types and relationship types (Figure 4-3). The object and relationship toolbars change according to the current language to show the available object and relationship types in that language. The commands on the action toolbar are fixed, and are (from left to right): Generate, Print, Cut, Copy, Paste, Undo, Redo, Align to Grid, Zoom , Default Zoom, Zoom to Fit and Delete. Depending on the modeling language and generator definitions in use, buttons for executing specific generators may also appear on the action toolbar. They will be grouped on the right side of the Delete button.

The buttons in the object type and relationship type toolbars represent the types of the current modeling language, and therefore change from language to language. Pressing these buttons will initiate the creation of the respective object or relationship type. Please note that there is also a separate generic relationship button, ‘Rel’, between the object and relationship buttons. This initiates the creation of any relationship type: the type of the relationship instance is determined from context, or prompted from the user when the creation is confirmed.

The visibility of the toolbars in each Diagram Editor window can be set from the View | Toolbar menu. Default visibility and layout of toolbars can be set in the Options Tool (see Section 3.1.3).

The drawing area is the main component of the Diagram Editor, and is used for creating and managing diagram elements. Diagram elements are graphical representations of conceptual model elements such as objects or relationships. The sidebar on the left side of the Diagram Editor provides an alternative interactive tree-view to the design data shown in the drawing area. The status bar at the bottom of the window shows the currently active diagram element and its sub-graphs, the grid setting and current zoom factor.