Computer Science 051 --- Homework Laboratory # 2 -- Part 2

Part 2

Once you get the basic version working, we would like you to jazz it up a bit. Here are the extensions we would like you to make:

Add labels (Text items) at the bottom of the picture showing the number of correct and incorrect placements. This makes it clearer when the student succeeds in placing the item correctly. They should read something like "correct = nn", "incorrect = mm". The value in the first Text item will be formed by concatenating the string "correct =" with an integer instance variable which keeps track of the number of correct answers. The other is similar.

Users should drag the items to the correct laundry basket rather than just clicking on the basket. Recall from the example in class that you will need an instance variable to label the last mouse position before the drag so you can determine how far to drag the item. If the user presses the mouse button down outside the laundry item, it should not increase the correct or the incorrect counter.

Assign the item a randomly generated color by randomly choosing integers redNum, greenNum, and blueNum between 0 and 255 for each of the red, blue, and green components of the color. You can create a color from those components by writing new Color(redNum,greenNum,blueNum)).

Now define criteria for determining where each color should go. A simple criterion is based on the sum of the three color components. If the sum of the component numbers is less than 230, decide it is dark, if it is greater than 600, decide it is white. Otherwise it is colored. After you get the program working you might want to experiment with other criteria.

We will let you figure out most of the details of how to add the features for the more advanced versions. One piece of advice is that for the second enhancement you will be dropping the onMouseClick method in favor of using the three methods:

onMousePress - for when the user first clicks on the item - though remember that they might miss.

onMouseDrag - to do the actual dragging (assuming they clicked on it originally).

onMouseRelease - if they were dragging it, check to see if they've dropped it in the right place when the mouse is released.

While we do not require you to bring a design document for this part of the program, you will find it extremely helpful to make some notes and sketch this out in advance, realizing that your work in part 1 will help you better understand how to do part 2.

Grading Guidelines

Value	Feature
	Design (1 pt total)
1/2	Variables and constants
1/2	Pseudo-code in begin & onMouseClick

	Style, Design, and Efficiency (10 pts total)
2 pts.	Descriptive comments
2 pts.	Good variable names
2 pts.	Good use of constants
2 pts.	Appropriate formatting
1 pt.	Does not generate new objects unnecessarily

	Correctness (10 pts total)
2 pts.	Generates a new color swatch only if previous one placed correctly
2 pts.	Swatch displayed in the correct initial position; returns to original location if incorrectly sorted
2 pts.	Updates number correct and incorrect properly
2 pts.	Drags swatch properly (-1 pt if can use clicking instead of dragging)
2 pts.	Appropriate behavior if user does unexpected things like starting to drag outside the swatch

	Extra credit (1 pt)
1 pt.	Does not update either # correct or # incorrect if user misses all baskets

Final remarks

Be sure to do the basic version of the lab before attempting the more advanced features. Just work on adding one feature at a time, testing each thoroughly before working on the next.

Turning in your program

Your program is due at 11p.m. on Monday evening. Turn in your program as you did last week. Here are the instructions again:

First, return to Eclipse and make sure you included your name and course number in a comment at the start of the program.

Next, click on the "Laundry" project in the Package Explorer panel on the left side of the Eclipse window.

Now, select "Export" from the "File menu.

Select "File system" in the dialog box and click next.

Make sure the folder with your project has a check mark next to it. (That will make all the files on the right have checks too!)

Click the "Browse" button next to the "To directory:" entry.

Double click on "Desktop".

Click the "Finish" button. It will create a new folder on your desktop.

Quit Eclipse.

Click on the new folder's name and type in a name for the folder that identifies you and the lab you are working on, such as "Yourname-Lab2" or "Yourname-Laundry" and then click "OK". (Dashes in names are OK, but don't include spaces or periods.)

Open the cs051 folder icon to find the "dropbox" folder.

Drag your new folder into the dropbox folder. When you do this, the computer will warn you that you will not be able to look at this folder. That is fine. Just click "OK".

The new folder will still show up on your desktop. Drag it into the trash both to save space and to keep anyone from copying it. (Files in your CSC 051 folder are protected so that others cannot read them.) Select "empty trash" from the file menu to completely delete those files. Do NOT throw away the version of the program in your workspace. You should save that so you can study it later.

If you should accidentally turn in a bad version of your program, you may drag another copy in as long as you change the name to be slightly different from the one you used before (e.g. Jane Doe - lab 2a). The new name should make it clear which is the newer version.

Good luck and have fun!

Part 2