Description
Introduction
This homework will cover images, buttons, and event handling.
Be sure to name your classes as required by the instructions. Also be sure to use good coding
style and indentation, and to use appropriate and descriptive variable names.
Do not forget about the collaboration policies detailed in homework 1, or about javadocing and
commenting detailed in homework 2 and 3.
Your finished homework will look something like this:
In this assignment, you’ll be programming a pet that a user can interact with. As the user plays
with the pet, different circumstances will put the pet into different states. We’ve drawn sample
images for each state, and have included them with this guide. You may also draw your own.
You can choose how you want to render the images on your GUI, but we recommend using the
ImageIcon + Jlabel method (link). You can change the image on a label using the setIcon(Icon)
method in JLabel.
5.1: Pet.java
Create a class called Pet, which will represent our pet. The pet will have 5 states: normal,
sleeping, eating, laughing, and dead.
1. Define an enumerated type called State, which contains the following types:
SLEEPING, EATING, DEAD, LAUGHING, and NORMAL. If you’ve forgotten how to
make an enum, check Chapter 4 for more details.
2. Make instance variables for the Pet. It should have a variable of type State to hold the
current state of the pet, an int to hold the pet’s hunger, and variables for all the
ImageIcons of the pet.
3. The pet should also have a final instance variable to represent how full the pet can be.
Call this variable FULL and set it initially to 10.
4. Create a constructor for the pet. The constructor should set the initial state to NORMAL,
set hunger to FULL, and instantiate all the ImageIcon instance variables.
5. You should have getters for the status and hunger instance variables, following standard
getter / setter naming convention.
6. Create the following methods:
a. getCurrentIcon: returns the ImageIcon corresponding to the current state of
the pet. For example, if the current state is SLEEPING, then it should return the
sleeping ImageIcon.
b. poke: sets the state of the pet to LAUGHING, and decrements the hunger variable.
If the pet is dead, do nothing.
c. feed: sets the state of the pet to EATING, and resets the hunger variable to
FULL. If the pet is already eating, then the pet will overeat, so the state of the pet
should be set to DEAD. If the pet is already dead, do nothing.
d. sleep: sets the state of the pet to SLEEP. Do not modify the hunger variable. If
the pet is dead, do nothing.
e. sit: sets the state of the pet to NORMAL, and decrements the hunger variable. If
the pet is dead, do nothing.
f. watch: randomly calls the poke, sleep, or sit method. If the pet is dead, do
nothing.
g. kill: sets the state of the pet to DEAD.
h. checkForStarvation: checks to see if the hunger value is zero. If it is, sets the
state of the pet to DEAD. Should be called in the poke and sit methods.
Don’t forget to javadoc the class, constructor, and methods, javadocing parameters where
applicable (see the previous homeworks for an example of this).
5.2: PetPanel.java
Create a class called PetPanel that extends JPanel. This will display the pet and provide
buttons for the user to interact with. It should have:
1. An instance variable to store the Pet, instance variables for the hunger display and
picture of the pet (both of type JLabel), and instance variables for the buttons (feed,
poke, watch, and kill). They should have the appropriate visibility / protection.
2. A constructor that takes a Pet parameter, and stores it into the instance variable.
3. Also in the constructor:
a. Set the size of the PetPanel
b. Instantiate the two JLabels. The pet label should use the current icon of the pet,
and the hunger label should use the current hunger of the pet.
c. Instantiate the four buttons (feed, poke, watch, and kill).
d. Add action listeners to the buttons (see step 5).
e. Add the labels and the buttons to the PetPanel.
4. A method called refresh which updates the pet label to use the current ImageIcon of
the pet, and updates the hunger label to use the current hunger of the pet.
5. An ActionListener to handle the event listening of the 4 buttons. This may be done
with a private inner class, or any other method you have learned. Make sure to call
refresh at the end of your actionPerformed method.
Don’t forget to javadoc the class, constructor, and methods, javadocing parameters where
applicable (see the previous homeworks for an example of this)
5.3: PetMain.java
Finally, create a class named PetMain with a main method that creates a JFrame, and brings
together a Pet object and a PetPanel object:
1. Create a JFrame, and set the default close operation
2. Create a Pet object.
3. Create a PetPanel object, using the Pet above.
4. Add the PetPanel to the JFrame.
5. Pack, and set the visibility of the JFrame.
Turn-in Procedure
Turn in the following files on T-Square. When you’re ready, double-check that you have
submitted and not just saved as draft.
• Pet.java
• PetPanel.java
• PetMain.java
• Any other files needed to run your program. Please include the state photos!
All .java files should have a descriptive javadoc comment.
Don’t forget your collaboration statement. You should include a statement with every homework
you submit, even if you worked alone.
Verify the Success of Your HW Turn-In
Practice “safe submission”! Verify that your HW files were truly submitted correctly, the upload
was successful, and that the files compile and run. It is solely your responsibility to turn in your
homework and practice this safe submission safeguard.
1. After uploading the files to T-Square you should receive an email from T-Square listing
the names of the files that were uploaded and received. If you do not get the confirmation
email almost immediately, something is wrong with your HW submission and/or your
email. Even receiving the email does not guarantee that you turned in exactly what you
intended.
2. After submitting the files to T-Square, return to the Assignment menu option and this
homework. It should show the submitted files.
3. Download copies of your submitted files from the T-Square Assignment page placing
them in a new folder.
4. Recompile and test those exact files.
5. This helps guard against a few things.
a. It helps insure that you turn in the correct files.
b. It helps you realize if you omit a file or files.**
(If you do discover that you omitted a file, submit all of your files again, not just
the missing one.)
c. Helps find last minute causes of files not compiling and/or running.
**Note: Missing files will not be given any credit, and non-compiling homework solutions will
receive few to zero points. Also recall that late homework (past the grace period of 2 am) will not
be accepted regardless of excuse. Treat the due date with respect. The real due date and time is 8
pm Friday. Do not wait until the last minute!
