Developing a Scenario

A scenario outlines the order of the events and operations that a tool will expect to perform and have performed. For example, the following scenario outlines the events that the ToolTalk demo program CoEd expects to perform and have performed:

1. User double-clicks on a document icon in the File Manager.

   The file opens in the editor, which is started by the system if one is not already running.

   If another tool has modifications to the text pending for the document, User is asked whether the other tool should save the text changes or revert to the last saved version of the document.

2. User inserts text.

3. User saves the document.

   If another tool has modifications pending for the document, User is asked whether to modify the document.

4. User exits the editor.

   If text has unsaved changes, User is asked whether to save or discard the changes before quitting the file.

Once the scenario is done, you can answer your basic questions.

How Will the Tools Work Together?

• The File Manager will request that CoEd open a document for editing.

• Each instance of CoEd will notify other interested instances of changes it makes to the state of the document.

What Kinds of Operations Do the Tools Perform?

• Each instance of CoEd can answer questions about itself and its state, such as "What is your status?"

• Each instance of CoEd has the capability of performing operations such as:

  • Iconifying and de-iconifying

  • Raising to front and lowering to back

  • Editing a document

  • Displaying a document

  • Quitting

What Kinds of Operations Can the Tools Ask Other Tools to Perform?

• The File Manager must request that CoEd open a document for editing.

• An instance of CoEd can ask another instance of CoEd to save changes to the open document.

• An instance of CoEd can ask another instance of CoEd to revert to the last saved version of the open document.

What Events Will the Tools Generate That May Interest Other Tools?

• The document has been opened.

• The document has been modified.

• The document has been reverted to last saved version.

• The document has been saved.

• An instance of CoEd has been exited.

What Events Generated by Other Tools Will Be of Interest to This Tool?

• The document has been opened.

• The document has been modified.

• The document has been reverted to last saved version.

• The document has been saved.

• An instance of CoEd has been exited.