Support Diagrams of Multiple Packages and Improve Package Support

[philip-alldredge]

support for diagrams that are not associated with a particular model element. Such diagrams shall allow diagrams containing multiple packages.

This initial implementation will include basic functionality.

• [x] Creating a diagram not associated with a model element. Need a wizard or something to create such diagrams.
• [x] Adding existing packages to such diagrams.
• [x] Support deleting packages.
• [x] Need to ensure this capability works correctly with the broken linkages support.

It is the intent at this time not to represent packages as hierarchical based on the nested names at this time. The general rationale for this is that is would substantially increase the complexity of the implementation because the graphical representation would less directly correspond to the actual AADL model. It may also lead users to believe that there is a package when in such a package may not actually exist. For example: "a::b" may exist but not "a". If represented hierarchically, "a" would appear in the diagram. However, such packages could be implicitly created when the user attempts to add classifiers to them. However, the intent is to avoid such complications until there is a clear use case and user desire for that capability.

[philip-alldredge]

@lwrage and @AaronGreenhouse I have updated the issue with my current thoughts regarding implementing this. We are considering whether a package should be create-able form the palette in the graphical editor. If that is implemented, it would be desired to reuse the AADL Package wizard. However, the graphical editor would need a way to hide the "Open With" section and perform its own handling after the wizard is completed. Instead of opening a new diagram/text editor, the behavior would need to be to add it to the diagram. Do you have any thoughts regarding issues refactoring the wizard or whether such package creation capability would be desired?