2. PC02 Consolidation
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3. This is the consolidation for this term
Introduction
This is the consolidation for this term
Has lots of exercises on all the topics covered
And some small things that are interesting, but you haven’t seen yet
Start at any point you want
Put all these in a single project called “Term01Consolidation”
And then packages for each topic you do

4. Choose a Topic to Recap Constructors JFrames JPanels GUI Components
Topic Index
Choose a Topic to Recap Constructors JFrames JPanels GUI Components

5. When making classes, we can add constructors
Functions that are run when an object of the class is instantiated
Setting memory aside on the computer for the object
Often used to ‘set up’ the object
Like giving instance variables values

6. When making classes, we can add constructors
Constructors (EX)
When making classes, we can add constructors
Functions that are run when an object of the class is instantiated
Setting memory aside on the computer for the object
Often used to ‘set up’ the object
Like giving instance variables values

7. Constructors (EX 1) Make a package called constructor_practice
In it, a class called Axolotl
Create two instance variables for the name and age
Create a constructor without any parameters
Sets name to “Unknown”
Sets age to 0
Outputs “Making an Axolotl with no known values” to the console
Create a class called ConstructorProgram (and give it the main)
Instantiate an Axolotl object (using the constructor you made)

8. Constructors (EX 2) Create a constructor in Axolotl with one parameter
The Axolotl’s name
This constructor should
Assign the parameter to name
Set the age to 0
Output “Making name, the Axolotl, with no known age”
Instantiate an Axolotl object in the ConstructorProgram main
Use this new constructor by giving it a name

9. Constructors (EX 3) Create a constructor in Axolotl with one parameter
The Axolotl’s age
This constructor should
Assign the parameter to age
Set the name to “Unknown”
Output “Making a age year old Axolotl with no name”
Instantiate an Axolotl object in the ConstructorProgram main
Use this new constructor by giving it an age

10. Constructors (EX 4)
Create a constructor in Axolotl with two parameters
The Axolotl’s name and age
This constructor should
Assign the parameters to the correct variables
Output “Making name, the age year old Axolotl”
Instantiate an Axolotl object in the ConstructorProgram main
Use this new constructor by giving it a name and an age

11. JFrames act as windows for a GUI
We add a JPanel to it to add other components
Can do three main things
Make JFrame with title
Set the close operation
Pack and show

12. JFrames (EX) Make a package called jframe_practice
In it, a class called JFrameProgram
Make a JFrame object:
Set it to quit the program when closed
Set its size
Make it visible
Try using pack() before making it visible
What’s the difference?

13. Allows multiple components to be shown
JPanels
Allows multiple components to be shown
Rather than just one via JFrames
Handles layout (e.g. BorderLayout, GridLayout)
Can also change colour
It’s background

14. JPanels (EX 1) Make a package called jpanel_practice
In it, a class called JPanelProgram
Make a JFrame window (and make it close the program on exit)
Make a JPanel object
Change its colour
Give it a preferred size
Add it to the window
Pack and show the window
What happens if you don’t pack()?

15. JPanels (EX 2) Set the layout of this JPanel to BorderLayout
Create two more JPanels
Give them both different colours
Give them both the same preferred size
Add one JPanel to the north of the main JPanel
Add the other JPanel to the south of the main JPanel

16. We have looked at multiple JComponents (things we add to a JPanel)
JLabel
JTextField
JButton
Each have different uses

17. Make a package called jcomponent_practice
JComponents (EX 1)
Make a package called jcomponent_practice
In it, a class called JComponentProgram
Make a JFrame window (and make it close the program on exit)
Make a JPanel object (using the BorderLayout)
Give the JPanel a colour and preferred size
Pack and show the window

18. JComponents (EX 2) Before packing the window, create a JLabel object
Set the font of the JLabel
Set the colour of the JLabel
Set the text to centrally align horizontally
Add the JLabel to the north of the JPanel
What does this look like now?

19. JComponents (EX 3)
Before packing the window, create a JTextField object
Set the font of the JTextField
Add the JTextField to the centre of the JPanel
What does this look like now?
Try adding the JTextField to a blank JPanel (with no layout)
And give JTextField a preferred size
Then add this new JPanel to centre of main JPanel
Does it look different?

20. JComponents (EX 4) Before packing the window, create a JButton object
Give the JButton an anonymous ActionListener
Make it get the text from the JTextField
And output the text to the console
Add the JButton to the south of the main JPanel

21. You will make a timer that counts down from the chosen number
Final Project
This will act as a final project (if you don’t need a recap on anything else)
You will make a timer that counts down from the chosen number

22. Make a new package called final_project Create a class called Program
Create a new JFrame

23. Set the following for the JFrame:
Final Project (2)
Set the following for the JFrame:
DefaultCloseOperation to WindowConstants.EXIT_ON_CLOSE
Resizable to false
Visible to true
Pack it

24. Make another class and call it TimerPanel Make it extend JPanel
Final Project (3)
Make another class and call it TimerPanel
Make it extend JPanel
Give it a constructor
Also give it three attributes:
private int maximum = 30
private int current = maximum
private boolean isRunning = false

25. We will need a label as well:
Final Project (4)
Change your size and layout. Because our class extends Jpanel, we can set it’s properties like this:
setPreferredSize(new Dimension(250, 100));
setLayout(new BorderLayout());
We will need a label as well:
JLabel label = new JLabel("" + current, SwingConstants.CENTER);
add(label, BorderLayout.CENTER);
label.setFont(new Font("Serif", Font.PLAIN, 72));

26. Next, make a new panel and 3 buttons:
Final Project (5)
Next, make a new panel and 3 buttons:
JPanel panel = new JPanel();
JButton reset = new JButton("Reset");
JButton pause = new JButton("Pause");
JButton play = new JButton("Play");
Add your buttons to the panel:
panel.add(play);
panel.add(pause);
panel.add(reset);

27. Next, make a new panel and 3 buttons:
Final Project (6)
Next, make a new panel and 3 buttons:
JPanel panel = new JPanel();
JButton reset = new JButton("Reset");
JButton pause = new JButton("Pause");
JButton play = new JButton("Play");
Add your buttons to the panel:
panel.add(play);
panel.add(pause);
panel.add(reset);

28. Now we need to add some action listeners All of them look like this:
Final Project (7)
Now we need to add some action listeners
All of them look like this:
play.addActionListener(new ActionListener() { @Override public void actionPerformed(ActionEvent e) { CODE } });

29. They should do the following things:
Final Project (8)
They should do the following things:
Play: isPlaying = true;
Pause: isPlaying = false;
Reset:
current = maximum;
label.setText("" + current);
isPlaying = false;

30. Final Project (9)
Finally, let’s add the main thread. Make a new Runnable, and in run() add an infinite while loop. It should do the following:
if (isPlaying) { if(current <=0){ isPlaying = false; } label.setText("" + current); current--; Thread.sleep(1000); } else { Thread.sleep(100); }

31. You will need a try catch block around the whole thing
Final Project (10)
You will need a try catch block around the whole thing
Also, make sure to call start().

32. THE END
Have a nice holiday!