Especially when working with large models, the Overview pane is quite helpful for keeping track of the big picture of the model.
Screen space is limited, and it is often impractical to view an entire diagram at one time. Scrolling around or zooming in and out repeatedly is time-consuming, inefficient, and generally annoying. The Birdview tab resolves these issues by maintaining a snapshot of the entire diagram that can be quickly referenced while working on a diagram.
The portion of the diagram visible in the Diagram pane is highlighted in the Birdview tab. You can change the display by dragging the highlighted portion within the birdview.
Perhaps you would like to keep track of a smaller section of the diagram, and then later decide to view the entire diagram again. This is easily done by adjusting the zoom factor in the Birdview tab.
To change the zoom factor of the Birdview tab:
Uncheck the box in the lower left corner of the pane.
Use the slider bar to change the zoom factor.
The scroll bars can be used to position the view as required.
The Birdview tab provides the means to resize the diagram in the Diagram pane as well. The view in the Birdview tab remains unchanged while the diagram itself is enlarged or reduced.
To change the zoom factor of the diagram in the Diagram pane:
Check the box in the lower left corner of the pane.
Use the slider bar to change the zoom factor.
Note that the zoom factor is set for each diagram individually. A zoom factor set for one diagram will not be applied to subsequently displayed diagrams.
The second tab in the Overview pane, called To-Do-Items, is a collection of critiques. This is a feature that originates from ArgoUML and was one of the motivations for Jason Robbins to start the project. It is a powerful auditing mechanism that discretely generates critiques about the model you are building. Critiques can be hints to improve your model, reminders that your model is incomplete in some areas, or errors that would cause generated code not to compile.
Critiques are arranged within this tab in a variety of ways. The following options are available for viewing critiques:
by Decision Type - Uncategorized, Behavior, Class Selection, Naming, Storage, Inheritance, Containment, Planned Extensions, State Machines, Design Patterns, Relationships, Instantiation, Modularity, Expected Usage, Methods, Code Generation, Stereotypes
by Diagrams - Seems to be broken
by Knowledge Type - Correctness, Syntax, Presentation, Completeness
by Offenders - Model Elements
by Posters - arranged according to the critic who reported them
by Priority - High, Medium, Low
To view the details of a critique, simply click on the critique. The details will be displayed in the 'To Do Items' tab of the Details pane, located to the right of the Overview pane.
You can move directly from a critique to the diagram where the issue occurs by double-clicking on the critique name in the Overview pane. The appropriate diagram will then be opened in the Diagram pane.