General Instructions

An observer has been assigned to your team. The observer should be viewed as an apprentice trying to learn both how to use the tool set and to understand the concepts underlying the analysis that you perform. Please assist them with their assignment and answer whatever questions they have.

For each of the tasks, you need to submit two things: a deliverable and a description. The deliverable is the solution to the task. The description is a short note on how you arrived at your solution. If you use any additional resources, please make a note of this in your description. Additional resources include:

• other tools, i.e. ones not included in the tool description in the workshop report
• information from the Internet, e.g. downloaded files or browsed documents
• people from outside the team

You may run the program to view its behaviour.
The observer may participate in the analysis of the subject system.
There will be a lunch break from 12-1PM.
Stop work at 5PM-- you've earned a break. Afterwards, you can work on your presentations, but your analysis should be essentially complete.

You have been assigned, along with some of your colleagues, to rescue the future development of the xfig application. You are placed under a new manager, a recent MBA graduate, who is impressed that you are going to use some fancy tools to get him and the rest of your new team up to speed.

The first thing the new manager would like you to do is to use your tool(s) to create some documentation which would summarize the main structures and architecture of the xfig application. He would also like you to explore how you would go about implementing some of the changes that were identified in the inherited "TODO" list.

Provide a textual and/or graphical summary of how the xfig source code is organized. This documentation should provide the manager with an overview of the system, and may include a call graph, subsystem decomposition, description of the main data and file structures or any other appropriate information. Use whatever format you think is appropriate, text files, HTML, Word documents, graphics, etc.

Deliverable: The documentation you have created.

1.2 Evaluate the structure of the application.

Your manager would like you to form an opinion on the structure of the xfig program. In particular, you should answer the following questions:

1. Was it well-designed initially?
2. Is this original design still intact?
3. How difficult will it be to maintain and modify?
4. Are there some modules that are unnecessarily complex?
5. Are there any GOTO's? If so, how many, what changes would need to be made to remove them?

Deliverable: Your opinion on the answers to the above questions, and justification for the above.

The manager would like you to examine in detail some of the tasks from the "TODO" list. He would like you to outline the changes that would need to be made to the code to complete the task (i.e. which parts will need to be modified) and the impact of the change on the rest of the system. Consider at least one of the following tasks (preferably more), order is not important.

2.1 Modify the existing command panel.

The buttons in the command panel, a.k.a. tool bar, at the top of the window are somewhat unconventional. The tool bar should be more consistent with those in other graphical user interfaces, with the headings "File", "Edit", and "View" justified to the left and "Help" menu item justified on the right side. The buttons currently in the command panel should be re-arranged in the follow way:

Identify which functions or files would need to be modified in order to implement this change.

Deliverable: A list of functions or files involved in the change.

2.2 Add a new method for specifying arcs.

Currently, arcs are created by specifying three points (you may want to run the program to try this out), which are then used to create a spline curve. Add a feature that allows a user to draw an arc by clicking on the centre of a circle and then selecting two points on the circumference, i.e. by specifying a radius and angle. Identify the functions and files that need to be changed to add this feature. Also explain the approach you would take to implement this new feature.

Deliverable: A list of functions or files involved in the change.

2.3 Bug fix: Loading library objects.

Loading objects from a library causes the program to crash. This error occurs when the user attempts to load a library object using the bookshelf icon on the left-hand side of the screen. When you click on this icon, a dialog box opens that allows you to select a Library and an object to load. Doing so will cause xfig to hang and eventually crash with a "Segmentation Fault" error. Identify the functions or files that need to be changed to repair this defect.

Deliverable: A list of functions or files involved in the repair.

Note: If there are no libraries available to load, it means that xfig was not able to locate a library directory. You can specify one at the command line using the -library_dir or -li switch. In the distribution, the Libraries subdirectory is found in the Examples subdirectory. To start xfig from the distribution root with this option, type:
     ./xfig -li ./Examples/Libraries

We would like you to prepare a short 15 minute presentation for Wednesday. During the presentation, we would like you to include the following topics:

• How long did it take you to read the source code into your tool?
• What difficulties did you encounter with your tool? Did it crash? Any other surprises?
• How long did you spend on the required tasks?
• What kind of documentation did you create?
• Which maintenance tasks did you do?
• How long did each of them take?

We will have a laptop available with Powerpoint if you wish to use this to prepare your talk. We also have some transparencies and pens if you would prefer to use those.