In this assignment, you are to extend the moving object examples shown in class, using the moving objects applet shown on Wednesday night.

Copy the example mObjApplet.java, including the classes mPoint.java, mRectangle.java, mOval.java, and mTriangle.java from the link above.

1. First, you are to either write a new child class to add to the collection of moving objects, or extend the existing classes by choosing one of the following:
• Make a class mImage. It should be a child of mRectangle. The constructor will have a URL parameter that allows it to download an image to store in an instance variable of the class. Later, it will use the method g.drawImage in its paint method to draw the image. Add "get" and "set" methods to change the width and height of the image. And decide what other "get" and "set" methods to allow.
• Make a class mString. It should be a child of mPoint, but will be very similar to mRectangle in keeping variables w and h for the bounding box of the string (in addition to a variable for the string itself, and possibly a font). The constructor will accept a location x,y and an initial string (and font) and use the FontMetrics class to figure out what w and h are for that string. Decide what "get" and "set" methods to allow. The methods checkboundary and isInside can be the same as for mRectangle. The paint method will use g.drawString to draw the string.
• Change the class mPoint so that it has a boolean instance variable called "fill". Then in each child class, test the value of fill to decide whether to draw an outlined object or a filled object. (For example, for mRectangle, you just decide whether to call g.drawRect or g.fillRect.) Add "get" and "set" methods for the value of fill.
2. Write an applet similar mObjApplet.java that uses two or more instances or the class that you wrote in part 1 above. Make sure that it tests the various features of the class. For mImage, have the applet sometimes change the size of the image. For mString, be sure to have different strings. For the classes with the fill variable, change whether the objects are filled or not.

 

Submit your assignment by linking the description of your problem and program as described in the homework guidelines and also links to the applet itself and the Java source code.