panel1.java~7~

java灵感设计

package controlpolygon;

import java.awt.*;
import javax.swing.JPanel;
import java.awt.geom.*;
import java.util.*;
import java.awt.event.*;

/**
 * <p>Title: ControlPolygonDemo</p>
 * <p>Description: This is a Control Polygon demo</p>
 * <p>Copyright: Copyright (c) 2002</p>
 * <p>Company: d6-125</p>
 * @author Liujun
 * @version 1.0
 */

public class Panel1 extends JPanel {
  BorderLayout borderLayout1 = new BorderLayout();
    //在此添加自己的变量
    int n = 5;//一个多边形有五个控制点
    int current = -1;//当前的控制点
    static   double SIZE = 12.0;//控制点大小
    Point2D []   points = new Point2D[5];//五个控制点

  public Panel1() {
    try {
      jbInit();
    }
    catch(Exception ex) {
      ex.printStackTrace();
    }
  }
  void jbInit() throws Exception {
    this.addMouseMotionListener(new java.awt.event.MouseMotionAdapter() {
      public void mouseDragged(MouseEvent e) {
        this_mouseDragged(e);
      }
    });
    this.addMouseListener(new java.awt.event.MouseAdapter() {
      public void mousePressed(MouseEvent e) {
        this_mousePressed(e);
      }
      public void mouseReleased(MouseEvent e) {
        this_mouseReleased(e);
      }
    });
    this.setLayout(borderLayout1);
       //add code here
         //产生五个初始的点，构造一个五边形
         points[0] = new Point2D.Double(100.0, 100.0);
         points[1] = new Point2D.Double(100.0, 150.0);
         points[2] = new Point2D.Double(130.0, 170.0);
         points[3] = new Point2D.Double(250.0, 260.0);
         points[4] = new Point2D.Double(300.0, 200.0);
 }

  void this_mousePressed(MouseEvent e) {
    Point p = e.getPoint();
      for (int i = 0; i < n; i++)
      {  double x = points[i].getX() - SIZE / 2;
         double y = points[i].getY() - SIZE / 2;
         Rectangle2D r = new Rectangle2D.Double(x, y, SIZE, SIZE);
         if (r.contains(p))//判断当前鼠标位置是否在控制点上
         {  current = i;//如果是，则设current为当前点
            return;
         }
      }
  }

  void this_mouseReleased(MouseEvent e) {
   current = -1;//鼠标被释放
  }

  void this_mouseDragged(MouseEvent e) {
     if (current == -1) return;//如果鼠标没有按下，则返回
      points[current] = e.getPoint();//设置当前点为鼠标的位置
      this.repaint();//重绘图形
  }
  protected void paintComponent(Graphics g) {
    /**@todo: Override this javax.swing.JComponent method*/
    super.paintComponent( g);
      if (points == null) return;
      Graphics2D g2 = (Graphics2D)g;//使用Java 2D
      for (int i = 0; i < n; i++)//画控制点
      {  double x = points[i].getX() - SIZE / 2;
         double y = points[i].getY() - SIZE / 2;
         g2.fill(new Rectangle2D.Double(x, y, SIZE, SIZE));
      }
      //重画多边形
      GeneralPath Polygon = new GeneralPath();
      Polygon.moveTo((float)points[0].getX(), (float)points[0].getY());
      for (int i = 1; i < n; i++)
         Polygon.lineTo((float)points[i].getX(), (float)points[i].getY());
      Polygon.closePath();
      g2.draw(Polygon);
  }
}