//四葉玫瑰：r=asin2θ,或r=acos2θ
//三葉玫瑰：r=asin3θ,或r=acos3θ
//星形線：x=asinθ.sinθ.sinθ,或y=acosθcosθcosθ
//心形線：r=a(1-cosθ)
//阿基米德螺線：r=aθ
//雙曲螺線：rθ=a
//伯努利雙紐線：rr=aasin2θ或rr=aacos2θ

import java.awt.*;
import java.awt.event.*;
public class DoubleLine extends Frame 
             implements WindowListener,ComponentListener,ItemListener
{
    int width1=600,height1=400;                //窗口尺寸 
    Color color = Color.blue;                  //畫線的顏色
    CheckboxGroup cg1 ;
    Checkbox  cb1,cb2,cb3;
    public DoubleLine()
    {
        setTitle("Rose");
        setSize(width1,height1);
        setBackground(Color.white);
        setLayout(new FlowLayout());
        addWindowListener(this);
        addComponentListener(this);
        cg1 = new CheckboxGroup();
        cb1 = new Checkbox("blue",cg1,true);
        cb2 = new Checkbox("red",cg1,false);
        cb3 = new Checkbox("green",cg1,false);
        cb1.addItemListener(this);
        cb2.addItemListener(this);
        cb3.addItemListener(this);
        add(cb1);
        add(cb2);
        add(cb3);
    }
    public void paint(Graphics g)
    {
        int x0,y0;                             //原點坐標
        x0 = width1 /2;
        y0 = height1 /2;
        g.setColor(color);
        g.drawLine(x0,0,x0,height1);
        g.drawLine(0,y0,width1,y0);
        int i,x,y;
        double pi=3.14,angle,r;
        for (i=0;i<1023;i++){
            angle = i*pi/512;
            r = 25/angle;
            x =(int) Math.round(r*Math.cos(angle)*2);
            y =(int) Math.round(r*Math.sin(angle));
            g.fillOval(x0+x,y0+y,1,1);     //畫圓點
        }
            
        
    }
    public void windowClosing(WindowEvent e)
    {
        System.exit(0);
    }
    public void componentResized(ComponentEvent e)   //改變窗口大小時
    {  
        width1 = getWidth();                         //取得窗口的大小
        height1 = getHeight(); 
    }
    public void itemStateChanged(ItemEvent e)
    {                                                //選中單選按鈕時
        if (e.getSource()==cb1)           //判斷產(chǎn)生事件對象e的組件是誰
            color = Color.blue;
        if (cb2.getState())                     //判斷單選按鈕cb2的狀態(tài)
            color = Color.red;
        if (cg1.getSelectedCheckbox()==cb3) //判斷復選框組cg1選中的是誰
            color = Color.green;
        repaint();                                   //重畫
    }
    public static void main(String arg[])
    {                            //創(chuàng)建并顯示Frame對象，F(xiàn)rame作為畫布
        new DoubleLine().setVisible(true);
    }
    public void componentMoved(ComponentEvent e)    {  }
    public void componentHidden(ComponentEvent e)   {  }
    public void componentShown(ComponentEvent e)    {  }
    public void windowOpened(WindowEvent e)         {  }
    public void windowActivated(WindowEvent e)      {  }
    public void windowDeactivated(WindowEvent e)    {  }
    public void windowClosed(WindowEvent e)         {  }
    public void windowIconified(WindowEvent e)      {  }
    public void windowDeiconified(WindowEvent e)    {  }
}