Abstract Factory

1// Abstract Products
2interface Button {
3    void render();
4    void onClick();
5}
6
7interface TextField {
8    void render();
9    String getValue();
10}
11
12interface Checkbox {
13    void render();
14    boolean isChecked();
15}
16
17// Concrete Products - Windows Family
18class WindowsButton implements Button {
19    public void render() { System.out.println("Windows-style button"); }
20    public void onClick() { System.out.println("Windows click"); }
21}
22
23class WindowsTextField implements TextField {
24    public void render() { System.out.println("Windows text field"); }
25    public String getValue() { return "Windows input"; }
26}
27
28class WindowsCheckbox implements Checkbox {
29    public void render() { System.out.println("Windows checkbox"); }
30    public boolean isChecked() { return true; }
31}
32
33// Concrete Products - Mac Family
34class MacButton implements Button {
35    public void render() { System.out.println("Mac-style button"); }
36    public void onClick() { System.out.println("Mac click"); }
37}
38
39class MacTextField implements TextField {
40    public void render() { System.out.println("Mac text field"); }
41    public String getValue() { return "Mac input"; }
42}
43
44class MacCheckbox implements Checkbox {
45    public void render() { System.out.println("Mac checkbox"); }
46    public boolean isChecked() { return false; }
47}
48
49// Abstract Factory
50interface UIFactory {
51    Button createButton();
52    TextField createTextField();
53    Checkbox createCheckbox();
54}
55
56// Concrete Factories
57class WindowsUIFactory implements UIFactory {
58    public Button createButton() { return new WindowsButton(); }
59    public TextField createTextField() { return new WindowsTextField(); }
60    public Checkbox createCheckbox() { return new WindowsCheckbox(); }
61}
62
63class MacUIFactory implements UIFactory {
64    public Button createButton() { return new MacButton(); }
65    public TextField createTextField() { return new MacTextField(); }
66    public Checkbox createCheckbox() { return new MacCheckbox(); }
67}
68
69// Client - works with abstractions
70class Application {
71    private Button button;
72    private TextField textField;
73    private Checkbox checkbox;
74    
75    public Application(UIFactory factory) {
76        button = factory.createButton();
77        textField = factory.createTextField();
78        checkbox = factory.createCheckbox();
79    }
80    
81    public void render() {
82        button.render();
83        textField.render();
84        checkbox.render();
85    }
86}
87
88// Usage
89public class Main {
90    public static void main(String[] args) {
91        // Determine OS and create appropriate factory
92        UIFactory factory;
93        String os = System.getProperty("os.name").toLowerCase();
94        
95        if (os.contains("windows")) {
96            factory = new WindowsUIFactory();
97        } else {
98            factory = new MacUIFactory();
99        }
100        
101        Application app = new Application(factory);
102        app.render();  // Renders OS-specific UI components
103    }
104}