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import java.awt.*;import java.awt.event.*;import javax.swing.*;public class HelloWorld3 { public static void main(String[] args){ JFrame frame = new JFrame(" HelloWorld3 "); frame.add(new HelloComponent3("Hellow")); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setSize(300,300); frame.setVisible(true); }}class HelloComponent3 extends JComponent implements MouseMotionListener,ActionListener { String theMessage; int messageX=125,messageY=95; JButton theButton; int colorIndex; static Color[] someColors={Color.black,Color.red,Color.green,Color.blue,Color.magenta}; public HelloComponent3(String message){ theMessage=message; theButton=new JButton("change message"); setLayout(new FlowLayout()); add(theButton); theButton.addActionListener(this); addMouseMotionListener(this); } public void painComponent(Graphics g){ g.drawString(theMessage, messageX, messageY); } public void mouseDragged(MouseEvent e){ messageX=e.getX(); messageY=e.getY(); repaint(); } public void mouseMoved(MouseEvent e){} public void actionperformed(ActionEvent e){ if(e.getSource()== theButton) changeColor(); } synchronized private void changeColor(){ if(++colorIndex==someColors.length) colorIndex=0; setForeground(currentColor()); repaint(); } synchronized private Color currentColor(){ return someColors[colorIndex]; } public void actionPerformed(ActionEvent e) { } } |
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