CS 10, Fall 2008
Assignment 2

Due: Wednesday, October 22, 9:00pm
Worth: 100 homework points

1. Write ColorScale.java as a class that represents a n-color scale, and with a public interface that matches our solution's ColorScale interface, including a similar set of javadoc comments.
   • This class is a generalized version of class FiveColorScale from Assignment 1. A ColorScale object is created by specifying a first color (level 0), and a last color (level size minus one). The object then calculates the intermediate colors so all the colors in order look like a smooth transition from the first through the last.
   • Include all the necessary public features:
     • A no-argument constructor that sets the first color to Color.WHITE, sets the last color to Color.BLACK, and sets size to 10.
     • A 3-argument constructor that lets a client set first and last colors, and the value of size:
              public ColorScale(Color first, Color last, int size)
       In this constructor, you may assume that size is at least 2.
     • A method to access a specified color level, get(int level). You may assume the level passed is in the range 0 to size minus 1.
     • And an access method for the size, size().
   • Use a copy of this application, ScaleTester.java (another copy is in ~mikec/cs10/hw2/ at CSIL) to initially test the class. This application uses CS10Display.class (from Assignment 1), so be sure a copy of that class is in your default directory. Your results must match these part 1 results from our solution.
2. Write a Java application named ShowColorScale.java as specified below to allow a user to select the colors and size of the scale shown.
   • Let the user specify a first and then a last color by selecting from a menu of options exactly like the menu in these part 2 runs of our solution. Notice the menu includes the names of the 13 constant colors of class Color. You may borrow our two arrays of these colors and their corresponding names:

             final Color[] stockColors = { Color.BLACK, Color.BLUE, Color.CYAN,
                 Color.DARK_GRAY, Color.GRAY, Color.GREEN, Color.LIGHT_GRAY,
                 Color.MAGENTA, Color.ORANGE, Color.PINK, Color.RED, Color.WHITE,
                 Color.YELLOW };
             final String[] stockNames = { "BLACK", "BLUE", "CYAN", "DARK_GRAY",
                 "GRAY", "GREEN", "LIGHT_GRAY", "MAGENTA", "ORANGE", "PINK",
                 "RED", "WHITE", "YELLOW" };

     Remember to offer choice "14: Other" in the menu too.
   • If the user enters anything except an integer in the range 1 to 14, then print an appropriate error message (see the sample runs) and display the menu again.
   • If choice 14 is selected for a color, then get the red, green, and blue values from the user for that color, just like the sample runs. If the user enters a non-integer or a value outside the range 0 to 255, then show an error message like the sample runs, and ask for that value again.
   • Also get the size (number of color levels) from the user. If the user enters a non-integer or a value less than 2, again display an appropriate error message and give the user another chance to enter the value.
   • Create a ColorScale object (part 1 of this assignment). Then get the component colors from this object, store these colors in an array of the appropriate size, and pass this array to the CS10Display.show method (see ScaleTester.java above).
3. Test your classes at CSIL. Then turn them both in at once from your engineering account as follows:
   
   turnin hw2@cs10 ColorScale.java ShowColorScale.java
   Late projects may not be accepted.

Updated 10/8/08 by C. Michael Costanzo