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

Part 2

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. The simplest 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.

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

Grading Guidelines

Value	Feature
	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
1 pt.	Design issues

	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

Turning in your program

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.

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

Double click on "Home".

Click the "Create Folder" button. Type in a name for the folder. A good folder name is one that identifies you and the lab you are working on, such as "Bruce-Lab2" or "Bruce-Laundry" and then click "OK". (Dashes in names are OK, but don't include spaces or periods.) Then click "Finish".

Quit Eclipse.

Double click on your Home folder. You should see the folder you just created.

Open a second window by double-clicking the cs051 folder icon on the left side of the screen. Within the "CSC 051" folder you should see a "dropbox" folder.

Drag your new folder into the dropbox folder. When you do this, the computer may 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 in your home folder. 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.) Press the right mouse button on the trash icon to bring up a menu and select "empty trash".

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