Consider the model/view/control example depicted in Figures 6-16 and 6-15.

a. Redraw the collaboration diagram of Figure 6-16 as a sequence diagram.

b. Discuss how the MVC architecture helps or hurts the following design goals

• Extensibility (e.g., the addition of new types of views).
• Response time (e.g., the time between a user input and the time all views have been updated
• Modiability (e.g., the addition of new attributes in the model
• Access control (i.e., the ability to ensure that only legitimate users can access specic parts of the model).

Figure 6-16 An example of MVC architectural style. The "model" is the filename 9DesignPAtterns2.ppt. One "view" is a window titled CBSE, which displays the contents of a folder containing the file 90esignPatterns2.ppt. The other "view" is window called 9DesignPatterns2.ppt Info, which displays information related to the file. If the file name is changed, both views are updated by the "controller." Figure 6-17 Sequence of events in the Model/View/Control architectural style (UML communication diagram)