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JAVA AWT: Choice, List & Canvas

Java AWT Choice

The object of Choice class is used to show popup menu of choices. Choice selected by user is shown on the top of a menu. It inherits Component class.

AWT Choice Class Declaration

  1. public class Choice extends Component implements ItemSelectable, Accessible  

Java AWT Choice Example

  1. import java.awt.*;  
  2. public class ChoiceExample  
  3. {  
  4.         ChoiceExample(){  
  5.         Frame f= new Frame();  
  6.         Choice c=new Choice();  
  7.         c.setBounds(100,100, 75,75);  
  8.         c.add("Item 1");  
  9.         c.add("Item 2");  
  10.         c.add("Item 3");  
  11.         c.add("Item 4");  
  12.         c.add("Item 5");  
  13.         f.add(c);  
  14.         f.setSize(400,400);  
  15.         f.setLayout(null);  
  16.         f.setVisible(true);  
  17.      }  
  18. public static void main(String args[])  
  19. {  
  20.    new ChoiceExample();  
  21. }  
  22. }  

Output:

java awt choice example 1

Java AWT Choice Example with ActionListener

  1. import java.awt.*;  
  2. import java.awt.event.*;  
  3. public class ChoiceExample  
  4. {  
  5.         ChoiceExample(){  
  6.         Frame f= new Frame();  
  7.         final Label label = new Label();          
  8.         label.setAlignment(Label.CENTER);  
  9.         label.setSize(400,100);  
  10.         Button b=new Button("Show");  
  11.         b.setBounds(200,100,50,20);  
  12.         final Choice c=new Choice();  
  13.         c.setBounds(100,100, 75,75);  
  14.         c.add("C");  
  15.         c.add("C++");  
  16.         c.add("Java");  
  17.         c.add("PHP");  
  18.         c.add("Android");  
  19.         f.add(c);f.add(label); f.add(b);  
  20.         f.setSize(400,400);  
  21.         f.setLayout(null);  
  22.         f.setVisible(true);  
  23.         b.addActionListener(new ActionListener() {  
  24.             public void actionPerformed(ActionEvent e) {       
  25.          String data = "Programming language Selected: "+ c.getItem(c.getSelectedIndex());  
  26.          label.setText(data);  
  27.         }  
  28.         });           
  29.         }  
  30. public static void main(String args[])  
  31. {  
  32.    new ChoiceExample();  
  33. }  
  34. }  

Java AWT List

The object of List class represents a list of text items. By the help of list, user can choose either one item or multiple items. It inherits Component class.

AWT List class Declaration

  1. public class List extends Component implements ItemSelectable, Accessible  

Java AWT List Example

  1. import java.awt.*;  
  2. public class ListExample  
  3. {  
  4.      ListExample(){  
  5.         Frame f= new Frame();  
  6.         List l1=new List(5);  
  7.         l1.setBounds(100,100, 75,75);  
  8.         l1.add("Item 1");  
  9.         l1.add("Item 2");  
  10.         l1.add("Item 3");  
  11.         l1.add("Item 4");  
  12.         l1.add("Item 5");  
  13.         f.add(l1);  
  14.         f.setSize(400,400);  
  15.         f.setLayout(null);  
  16.         f.setVisible(true);  
  17.      }  
  18. public static void main(String args[])  
  19. {  
  20.    new ListExample();  
  21. }  
  22. }  

Output:

java awt list example 1

Java AWT List Example with ActionListener

  1. import java.awt.*;  
  2. import java.awt.event.*;  
  3. public class ListExample  
  4. {  
  5.      ListExample(){  
  6.         Frame f= new Frame();  
  7.         final Label label = new Label();          
  8.         label.setAlignment(Label.CENTER);  
  9.         label.setSize(500,100);  
  10.         Button b=new Button("Show");  
  11.         b.setBounds(200,150,80,30);  
  12.         final List l1=new List(4, false);  
  13.         l1.setBounds(100,100, 70,70);  
  14.         l1.add("C");  
  15.         l1.add("C++");  
  16.         l1.add("Java");  
  17.         l1.add("PHP");  
  18.         final List l2=new List(4, true);  
  19.         l2.setBounds(100,200, 70,70);  
  20.         l2.add("Turbo C++");  
  21.         l2.add("Spring");  
  22.         l2.add("Hibernate");  
  23.         l2.add("CodeIgniter");  
  24.         f.add(l1); f.add(l2); f.add(label); f.add(b);  
  25.         f.setSize(450,450);  
  26.         f.setLayout(null);  
  27.         f.setVisible(true);  
  28.         b.addActionListener(new ActionListener() {  
  29.          public void actionPerformed(ActionEvent e) {       
  30.           String data = "Programming language Selected: "+l1.getItem(l1.getSelectedIndex());  
  31.           data += ", Framework Selected:";  
  32.           for(String frame:l2.getSelectedItems()){  
  33.                    data += frame + " ";  
  34.           }  
  35.           label.setText(data);  
  36.           }  
  37.          });          
  38. }  
  39. public static void main(String args[])  
  40. {  
  41.    new ListExample();  
  42. }  
  43. }  

Output:

java awt list example 2

Java AWT Canvas

The Canvas control represents a blank rectangular area where the application can draw or trap input events from the user. It inherits the Component class.

AWT Canvas class Declaration

  1. public class Canvas extends Component implements Accessible  

Java AWT Canvas Example

  1. import java.awt.*;  
  2. public class CanvasExample  
  3. {  
  4.   public CanvasExample()  
  5.   {  
  6.     Frame f= new Frame("Canvas Example");  
  7.     f.add(new MyCanvas());  
  8.     f.setLayout(null);  
  9.     f.setSize(400, 400);  
  10.     f.setVisible(true);  
  11.   }  
  12.   public static void main(String args[])  
  13.   {  
  14.     new CanvasExample();  
  15.   }  
  16. }  
  17. class MyCanvas extends Canvas  
  18. {  
  19.         public MyCanvas() {  
  20.         setBackground (Color.GRAY);  
  21.         setSize(300, 200);  
  22.      }  
  23.   public void paint(Graphics g)  
  24.   {  
  25.     g.setColor(Color.red);  
  26.     g.fillOval(75, 75, 150, 75);  
  27.   }  
  28. }    
Anurag Rana Educator CSE/IT

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