Write several JFrame subclasses (customizations) in order
to practice with writing classes, methods, method calls (including
the use of arguments and parameters), and expressions. We will have
taught all the material required for this assignment by the end
of week 2.
You may work with one partner. If you do, get on the course management system several days before the assignment is due and follow directions for telling the system who your partner will be. Don't wait until the last minute to do this; do it several days before you want to submit the assignment.
This is (very, very roughly) a 10-hour assignment. Plan accordingly.
Plan to spend as much as an hour reading this handout so that you thoroughly understand what we are asking for. Do this with your partner before you start programming!
We strongly, strongly suggest that you and your partner alternate writing the classes (but with the other person watching and helping). You will both benefit from this, even if you find it feels like it is taking longer.
Here are some very specific rules that you must follow. If you break any of these, you will automatically get a zero on part or all this assignment.
static
anywhere in assignment 1. public,
and every instance variable must be marked private.
System.out.println or
System.out.print in any class that you write.JFrame You will write several subclasses of JFrame. Here are the
sources of help that you can use, in no particular order: the course
textbooks, your lecture notes, your programming partner, the course
website, the Java APIs, the consultants in Carpenter, the TAs, and
the instructor.
You should write a short javadoc comment at the top of each class that describes what the class is for. You should write a comment for each method. As a reminder, javadoc comments look like these:
/** this is a javadoc comment for class X */
public class X {
/** this is a javadoc comment for method m.
Put a blank line before me. */
public void m() {
}
}
The comment on a method MUST be a specification of the method. It should
follow the guidelines given in Sec. 13.3.1 of the text. Also, use the
specifications shown in Sec. 2.1 as examples. One way to get the specification
is simply to copy it from the material below.
Here are the five subclasses that you should write:
JFrame that
can double and halve its height. Has these additional methods:
doubleHeight(). Double this window's height.halveHeight(). Cut this window's height in half. Hints:Write and check out one method at a time. In the Interactions
pane, initialize a JFrame and figure out a statement
that doubles the size of that window. Then write the subclass outline,
copy the statement into the method, and change the variable name to
"this". Also, check your lecture notes.
Note: doubling and halving may stop working properly if the windows
become too large for your screen or too small. Don't worry about this;
your class need work only when the window is of a reasonable size.
JFrame that can be
resized in several different ways. Has these additional methods:
changeSizeToLoc(). Change this window's width to
this window's X coordinate and set this window's height to this
window's Y coordinate. addToSize(int dW, int dH). Add dW to
this window's width and dH to this window's height.
swapOrientation(). Change this window's height to
its width and its width to its height. Hints: write and test one method at a time. For example, after you
write class SizingFrame and method changeSizeToLoc,
try this in the Interactions pane:
SizingFrame rw= new SizingFrame();
rw.show();
rw.setLocation(400, 400);
rw.changeSizeToLoc();
You should see the window change shape.
JFrame that can get
its size and location from a Date object. Has these additional
methods:
setSizeAndLocToDate(Date d). Set this window's height
to 120 + (d's year modulo 300), set this
window's width to 120 + (d's month times 10),
set this window's X coordinate to 50 + (d's hour times
5), set this window's Y coordinate to 50
+ (d's seconds times 5), and set this window's
title to the value of "Date " + d.toString().
b modulo c using b % c . JFrame that can create
a partner frame. Has these additional methods:
createPartner(). Create a JFrame that
is 50 pixels wider and 50 pixels taller than this frame and has
its top-left corner 25 pixels to the left and 25 pixels up from
this frame. The original frame should appear on top of this one,
so that the partner sort of "frames" this original one. resetPartner(). Resize the partner frame so that
it is 50 pixels taller and wider than this frame and move it so
that it "frames" this frame, as discussed in method createPartner.
Again, this partner should appear behind this frame. This method
is called only after createPartner has been called.getPartner(). = The partner (null if not yet created).
That is, return the name of the manilla folder of the partner frame. Note: The first method creates a partner frame; the second one doesn't.
It just moves and resizes the partner. For example, you, the user,
can drag and resize the frame; then you can call resetPartner to fix
its partner.
Hint: Save the partner frame as an instance variable. Draw a picture
to work out the coordinates before you program it.
Hint: You have to show the partner frame in the two methods; otherwise,
it won't become visible. You will also want to show the main frame
itself, so that it appears before the partner frame.
Hint: Methods createPartner and resetPartner have much in common.
See whether you can put most of the work in one of them and call that
one from the other one.
JFrame that can create
a "cross" of frames around it. Has these additional methods:
createCross(). Create 4 JFrames that
are all half the size of this frame (i.e. the width is half the
size and the length is half the size). One appears just above this
frame and is centered horizontally. In the same way, one appears
below and is centered horizontally, one appears to the left and
is centered vertically, and one appears to the right and is centered
vertically. Thus, the five frames look something like a cross. resetCross(). Move and resize the 4 frames created
in createCross so that they are all half the size
of this frame and and are positioned as explained in the specification
of method createCross. This method is called only
after createCross has been called.getTop(). = the partner that is above this frame
(null if not yet created). That is, return the name of the partner
frame above this one.getBottom(). = the partner that is below this frame
(null if not yet created). That is, return the name of the partner
frame below this one.getLeft(). = the partner that is to the left of this
frame (null if not yet created). That is, return the name of the
partner frame that is to the left of this one.getRight(). = the partner that is to the right of
this frame (null if not yet created). That is, return the name of
the partner frame that is to the right of this one. Hint: save the partner frames as instance variables. Draw pictures
to work out the coordinates.
Note: Suppose frame N is the one that goes above this frame. Suppose
N's width is w and its height is h. Then the top-left corner of N
MUST be h+1 pixels above and w/2 pixels to the right of the top-left
corner of this frame. Similar statements hold for the other three
frames.
Hint: Methods createCross and resetCross have much in common. See
whether you can put most of the work in one of them and call that
one from the other one.
Note: Windows apparently has a minimum width of 112 pixels. Even if
you do j.setSize(0, 0);, the width is 112. You don't need
to fix this, and you will not be penalized for this.
Use link http://cms.csuglab.cornell.edu/
to get on the course website and submit the following five files.
DoublingHalvingFrame.java,SizingFrame.java,DateFrame.java,FramingFrame.java,CrossFrame.java.