CSE 142

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Homework 3 (Doodle / Circles) FAQ

Q: How do I download DrawingPanel.java?
A: There's a link to it on the homework page from the course website.

Right-click on the link for DrawingPanel.java and click "Save Target As..." (in Internet Explorer) or "Save Link As..." (in Firefox). Then save the file in the same folder where your Java programs are being stored. Keep the file name the same, or it will not work.
Q: Do I really need to have those 2 methods on the assignment sheet? Can I have additional methods?
A: Yes, you need to have those two methods if you want full credit. You can have more methods besides those two if you want, but honestly you don't really need any others. A solution with many more methods is probably misunderstanding something about the assignment requirements. For example, creating a separate method for each of figure is a terrible idea.
Q: How picky are you going to be in grading Doodle.java? Is this creative enough?
A: In general we're going to be very lenient with the grading of the Doodle.

The reason we ask for a few shapes and colors is so that a student won't just turn in a blank panel (or a totally trivial picture, such as one black line) and say, "Well you told me I could do anything I wanted. Ha ha ha." We just ask for two colors because we want you to call setColor at least once.

In general if you're drawing any sort of figure that you've created, you will get the points. The guidelines listed are just there so we can mark off people who clearly didn't even try to submit anything nontrivial.

Your Doodle will not be graded on style or internal correctness.
Q: How many pixels can my image differ by?
A: The number isn't important. You should get the credit as long as your image doesn't have any differences noticeable to the naked eye.
Q: My program says, Cannot find symbol: Graphics, or Color. What is wrong?
A: Remember that you need to include the command "import java.awt.*;" at the top of your program.
Debugging Graphics
You can request a special version of the Graphics object that keeps a count of how many times basic drawing commands are performed. The method getDebuggingGraphics should be used instead of getGraphics to obtain this version:
    Graphics g = panel.getDebuggingGraphics();
 You can print the counts for the drawing methods by calling the getCounts method of the DrawingPanel class as the last line of main:
    System.out.println(panel.getCounts());
 There are different ways to correctly solve this problem, so your counts do not have to match if you manage to get 0 pixels of difference when your graphical output is compared to the expected output. But if you have a pixel difference, then the counts can provide you a sense of what you might be doing incorrectly (e.g., performing a drawing command too many times or too few times). Our sample solution produced these counts:
    {drawLine=128, drawOval=176, drawRect=3, fillOval=32, fillRect=3}