Mousing

package swingExamples;

import java.awt.Color;
import java.awt.Container;
import java.awt.Cursor;
import java.awt.Graphics;
import java.awt.Point;

import java.awt.event.InputEvent;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;

import javax.swing.JFrame;
import javax.swing.JPanel;

class MouseScribblePanel extends JPanel
{
  // Constructor
  public MouseScribblePanel()
  {
    addMouseListener( new MouseHandler() );
    addMouseMotionListener( new MouseMotionHandler() );
    setBackground(Color.RED);
  }
  
  // Utility method to determine the color to use
  private Color getEventColor(MouseEvent e)
  {
    Color color = Color.WHITE; // No modifiers means white
    
    int modifiers = e.getModifiers();
    if ( (modifiers & InputEvent.SHIFT_MASK) != 0)
    {
      color = Color.BLACK; // SHIFT key means black
    }
    else if ( (modifiers & InputEvent.CTRL_MASK) != 0)
    {
      color = Color.ORANGE; // CTRL key means orange
    }
    else if ( (modifiers & InputEvent.META_MASK) != 0)
    {
      color = Color.BLUE; // Mouse button 2 means blue
    }
    return color;
  }
  
  ///// Private Data /////
  private Point m_start, m_end;
  
  ////////// Inner classes ////////
  
  class MouseHandler implements MouseListener
  {
    // MouseListener method
    public void mousePressed(MouseEvent e)
    {
      int x = e.getX();
      int y = e.getY();
      m_start = new Point(x, y);
      m_end = new Point(x, y);
      int clickCount = e.getClickCount();
      if (clickCount == 2) // double click?
      {
        Graphics g = getGraphics();
        g.setColor(getEventColor(e));
        g.drawOval(m_start.x, m_start.y, 70, 30);
      }
    }
    
    public void mouseEntered(MouseEvent e)
    {
      setCursor(Cursor.getPredefinedCursor(Cursor.CROSSHAIR_CURSOR));
    }
    
    public void mouseExited(MouseEvent e)
    {
      setCursor(Cursor.getDefaultCursor());
    }
    
    // Unused MouseListener methods
    public void mouseClicked(MouseEvent e)
    {}
    public void mouseReleased(MouseEvent e)
    {}
  }
  
  class MouseMotionHandler implements MouseMotionListener
  {
    public void mouseDragged(MouseEvent e)
    {
      int x = e.getX();
      int y = e.getY();
      m_end = new Point(x, y);
      Graphics g = getGraphics();
      g.setColor(getEventColor(e));
      g.drawLine(m_start.x, m_start.y, m_end.x, m_end.y);
      m_start = new Point(x, y); // Drag from here next
    }
    
    // Unused MouseMotionListener methods
    public void mouseMoved(MouseEvent e)
    {}
  }
}

class MouseScribbleFrame extends JFrame
{
  public MouseScribbleFrame()
  {
    setTitle("Mouse Scribble");
    setSize(300, 200);
    setDefaultCloseOperation(EXIT_ON_CLOSE);
    Container contentPane = getContentPane();
    contentPane.add(new MouseScribblePanel());
  }
}

public class MouseScribble
{
  public static void main(String[] args)
  {
    MouseScribbleFrame frame = new MouseScribbleFrame();
    frame.setVisible(true);
  }
}