circlepanel.java

使用java语言编写的画图板

/*
 * circlepanel.java
 *
 * Created on 2005年12月25日, 下午3:51
 */

package painttool;

/**
 *
 * @author cb
 */
import java.io.*;
import java.awt.*;
import java.awt.event.*;

public class circlepanel
{
   public static int dotnumber=1;
   public static Button drawcircle=new Button("drawcircle");
   public static Button clear=new Button("clear");
   public static Button construct=new Button("建立坐标");
   public static TextField  t1=new TextField();
   public static TextField  t2=new TextField();
   public static TextField  t3=new TextField();
    public circlepanel()
    {
        TextField  t1=new TextField();
        TextField  t2=new TextField();
        TextField  t3=new TextField();
        
        BorderLayout bl=new BorderLayout();            
        Button b1=new Button("center");
        Button b2=new Button("edge");
        Button b3=new Button("radius");
        Panel p=new Panel();
        Panel p1=new Panel();
        Panel p2=new Panel();
        Main.circlep.setLayout(new BorderLayout()); 
        Main.circlep.add(p,bl.SOUTH);        
        p.setLayout(new GridLayout(1,2));
        p.setVisible(true);
        p1.setVisible(true);p2.setVisible(true);
        p1.setLayout(new GridLayout(1,3));
        p2.setLayout(new GridLayout(2,3));
        p.add(p1);p.add(p2);         
        p1.add(drawcircle);p1.add(clear);p1.add(construct);
        p2.add(b1);p2.add(b2);p2.add(b3);
        p2.add(t1);p2.add(t2);p2.add(t3);
        monitorc watch=new monitorc();
        clear.addActionListener(watch);
        drawcircle.addActionListener(watch);
        construct.addActionListener(watch);
        Main.circlep.addMouseListener(watch);
        Main.card.show(Main.mainFrame,"third");
        Main.card.show(Main.mainFrame,"second");        
    }
}
class monitorc extends Canvas implements MouseListener,ActionListener
{
    int x1=0,x2=0,y1=0,y2=0;
    int k=0;
    public void actionPerformed(ActionEvent e)
    {
       Graphics g=Main.circlep.getGraphics();
      
       if(e.getSource()==circlepanel.drawcircle)
       {
           k=(int)Math.sqrt((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2));
           drawcirclemid(k,x1,y1);
       }
       if(e.getSource()==circlepanel.construct)
       {           
           int i=0;
           g.drawLine(0, 200, 400, 200);
           g.drawLine(200, 0, 200, 400);
           while(i<200)
           {
               g.drawString(""+i,200+i,200);
               i=i+40;
           }
           i=0;
           while(i<200)
           {
               g.drawString(""+(-200+i),i,200);
               i=i+40;
           }
           i=0;
           while(i<200)
           {
               g.drawString(""+i,200,200+i);
               i=i+40;
           }
           i=0;
           while(i<200)
           {
               g.drawString(""+(-200+i),200,i);
               i=i+40;
           }
       }
       if(e.getSource()==circlepanel.clear)
       {           
            g.clearRect(0,0,400,350);
            circlepanel.t1.setText("");
            circlepanel.t2.setText("");
            circlepanel.t3.setText(""); 
            x1=0;x2=0;y1=0;y2=0;
            k=0;
            circlepanel.dotnumber=1;
       }      
    }    
    public void mouseClicked(MouseEvent e)
    {   
        Graphics g=Main.circlep.getGraphics();
          if(circlepanel.dotnumber==1)
            {  
                x1=e.getX();y1=e.getY();
                circlepanel.t1.setText(""+e.getX());
                circlepanel.t2.setText(""+e.getY());     
                g.drawString("start", e.getX()-20,e.getY());
            }
            if(circlepanel.dotnumber==2)
            { 
                x2=e.getX();y2=e.getY();                
                g.drawString("end", e.getX(),e.getY());
            }
            g.drawLine(e.getX(),e.getY(),e.getX(),e.getY());
            circlepanel.dotnumber++;
        
          
        
    }     
    public void mouseReleased(MouseEvent e){   }  
    public void mousePressed(MouseEvent e){   } 
    public void mouseEntered(MouseEvent e){   } 
    public void mouseExited(MouseEvent e) {   }
    public void drawcirclemid(int r,int x1,int y1)
    {
            Graphics g=Main.circlep.getGraphics();
            //g.drawLine(33,33,55,55);
             int deltax=0,deltay=0,d=0;
             int x=0,y=0;
                 deltax=3;
	         deltay=2-(int)r-(int)r;
	         d=1-(int)r;
	         x=0;
	         y=(int)r;
	         while(x<y)
	         {
	         	if(d<0)
	         	{
	         		d+=deltax;
	         		deltax+=2;
	         		x++;
	         	}
	         	else
	         	{
	         		d+=(deltax+deltay);
	         		deltax+=2;
	         		deltay+=2;
	         		x++;
	         		y--;
	         	}
	         	deltax=3;
	         deltay=2-r-r;
	         d=1-r;
	         x=0;
	         y=r;
	         while(x<y)
	         {
	         	if(d<0)
	         	{
	         		d+=deltax;
	         		deltax+=2;
	         		x++;
	         	}
	         	else
	         	{
	         		d+=(deltax+deltay);
	         		deltax+=2;
	         		deltay+=2;
	         		x++;
	         		y--;
	         	}
	         	g.drawLine(x+x1,y1-y,x+x1,y1-y);
	         	g.drawLine(x1-x,y1+y,x1-x,y1+y);
	         	g.drawLine(x1-x,y1-y,x1-x,y1-y);
	         	g.drawLine(x+x1,y1+y,x+x1,y1+y);
	         	g.drawLine(x1-y,x+y1,x1-y,x+y1);
	         	g.drawLine(x1+y,y1-x,x1+y,y1-x);
	         	g.drawLine(x1+y,x+y1,x1+y,x+y1);
	         	g.drawLine(x1-y,y1-x,x1-y,y1-x);
	         		         	
	         	
	         } 


	         } 

    }
}