CSC305 Summer Lecture 06

Individual Software Design and Development
Listeners
(202508)

Transcript

1. Dr. Javier Gonzalez-Sanchez javiergs@calpoly.edu www.javiergs.info o ffi ce: 14 -227 CSC 305 Individual Software Design and Development | Summer Version Lecture 06. Listeners
2. Previously
4. Observer Patterns
5. cat observes __ 5
6. Scenario 6 Observer + update() Observable + addObserver() + notifyObservers() + setChanged() Teacher Student Main
7. Observer public interface Observer { public abstract void update(Observable s); } 7
8. Observable import java.util.LinkedList; public class Observable { private LinkedList<Observer> observers = new LinkedList<Observer>(); public void addObserver(Observer observer) { observers.add(observer); } public void removeObserver(Observer observer) { observers.remove(observer); } public void notifying() { for (Observer ob : observers) { ob.update(this); } } } 8
9. Student as Observer class Student implements Observer { public String answerQuestion (String question) { String answer; // solve the question return answer; } @Override public void update(Observable s) { String q = ((Teacher)s).getQuestion(); Sting answer = answerQuestion (q); System.out.println (answer); } } 9
10. Teacher as Observable class Teacher extends Observable { private String question; public String getQuestion() { return question; } public void createQuestion () { // your code here notifying(); } } 10
11. Main public class Main { public static void main(String[]a) { Teacher teacher = new Teacher(); Student s1 = new Student(); Student s2 = new Student(); teacher.addObserver(s1); teacher.addObserver(s2); // Teaching teacher.createQuestion(); // More Teaching teacher.createQuestion(); } } 11
12. Listeners
13. Release 1. GUI 13
15. Release 2. Action Listeners 15
16. Standard Solution:
18. Release 3. Draw Area 18
21. Release 4. Mouse Listeners 21
23. MouseListener • public void mousePressed (MouseEvent e) {} • public void mouseClicked(MouseEvent e) { } • public void mouseRele a sed(MouseEvent e) { } • public void mouseEntered(MouseEvent e) { } • public void mouseExited(MouseEvent e) { } • public void mouseDr a gged(MouseEvent me) { } • public void mouseMoved(MouseEvent e) { } 23
24. MouseMotionListener • public void mouseDr a gged(MouseEvent me) { } • public void mouseMoved(MouseEvent e) { } 24
25. Release 5. Draw + Mouse 25
27. Listeners 27 • ActionListener • actionPerformance(ActionEvent e) {} • addActionListener (this);
28. Paint 28
29. Full Example 29 https://github.com/CSC3100/App-Paint/
30. One Last Thing
31. How to show a Dialog Box? 31
32. How to show a Dialog Box? 32 JOptionPane.showMessageDialog (this, "Hello, I am a dialog box!");
33. Homework
34. Homework Reuse (Complete as needed) your Code from Assignment 1 Add a GUI + Listeners Class Diagram (Use Astah Tool)
35. GUI 35 Bonus: Draw the name of the file inside
36. Questions 36
37. Lab.
38. TicTaeToe 38 O O X Dr a w the Squ a res ( a nd the O a nd X), i.e., Use f illRect, dr a wOv a l, dr a wString, etc. methods
39. Lab. What about a new version for TicTaeToe 1. Cre a te a Jfr a me a nd a Jp a nel 3. Dr a w the 9 boxes to represent the TicT a cToe 5. Add MouseListeners to detect clicks on the P a nel 7. Review if the click is inside of a box 9. If so, dr a w a nd X or a 0 on th a t position (one time X, the next O, the next X, etc) Do not worry a bout the g a me (Tic-T a c-Toe) logic, yet. The go a l of this l a b is just a GUI with listeners 39
40. CSC 305 Individual Software Design and Development Javier Gonzalez-Sanchez, Ph.D. javiergs@calpoly.edu Summer 2025 Copyright. These slides can only be used as study material for the class CSC305 at Cal Poly. They cannot be distributed or used for another purpose.