Finishing HW5

PositionalGraphic Class Design

• You should have your basic PositionalGraphic class completed, with the following 3 instance variables:

  1. private Rectangle boundingRectangle;
  2. private Color color;
  3. private boolean debug;

• If you also have a fill instance variable that's fine too, although un-filled shapes won't be used for this assignment. If you code it, make sure to code all the corresponding setters and getters and update any other code that should access it. If you do not fully-code the attribute, take it out of your class.

• Note that because the Rectangle class is a complex class, with x and y, plus width and height, you should have more than the basic 3 setters and getters.

• And with your color, you should have 2 setters - if you don't know what they are by now, discuss it on Piazza with your colleagues.

• What about a setCenter() method? It needs no extra instance variables, but could come in handy. Should it be in the parent class? If not, you will need to add it to at least some of your child classes.

• What other methods might come in handy for your child classes? If it's not specific to one child, write it in the parent. And, write it even if you are not sure it you will use it! Remember this is basic class design - you class is meant to be used by many programs, so iif it makes sense, write it.

Basic-Shape Child Class Design

• You should also have at least some of your basic shape classes; each extends PostionalGraphic and their paint() methods use the bounding-rectangle getters to figure out where, and how large to draw themselves.

• Each of the basic-shape child classes should also call the parent paint() method, and if (and only if) debug is on, as discussed in Piazza, the bounding rectangle is drawn (I suggest using red).

• Which of these child classes have additional instance variables?

  Here's a hint: only the Triangle class require any extra, and it have ONLY 1 additional one.

  The RectanglePG class can be coded without any extra ones.

  The HalfCirclePG class could use 1 or 2 extra, but it is not required for this assignment. Again, can you figure out what they might be?

• Other than paint() and toString(), is there any reason for the basic shape child-classes to override any other parent-class methods?

  Hint: technically, there is one class that should override setShapeSize() - can you think what this is and why? Note: Post this on Piazza if you figure it out; if not, then don't worry about it.

• What are the additional methods that should be added in the child classes?

Complex-Shape Child Class Design

Make sure you are ready to discuss the complex classes during lecture:

1. What additional instance variables do these classes have?

2. What additional methods do these classes have?

3. These classes demonstrate composition because they both are PositionalGraphic objects and have PositionalGraphic objects (isa and hasa).

   How does this affect your child-class design?

   How does this affect the methods that need to be overidden, such as paint(), toString(), setShapeSize(), setBoundingRectangle, setShapeLocation(), setCenter(), ...?

Final Application

Note: No one has asked about the prompting for the IceCreamConePG class test program - might be a good idea for you to discuss on Piazza ... This will help you with your class design too, and I have give you permission to discuss it, but remember no posting code!

• Your final application will do the following:

  1. Update the application called ShowShapes.java.
  2. It will display each of your shapes on the screen in a different position.
  3. To display multiple shapes, you will use this code HoldShapes.java to start from. Your ShowShapes application adds it just like the other shape-testing main programs added the individual shapes.
  4. Read the comments in the code to figure out how to update it for your class hierarchy.
  5. Note: do NOT change the code I've given you; it is written this way on purpose.
  6. The only prompting will be in your ShowShapes code for the IceCreamCodePG class - so, yes you will need to figure that out.