shapemain.java

用java编的一个画图

//#8.15
//#filename: ShapeMain.java

import javax.swing.*;
import java.awt.event.*;
import java.awt.*;

public class  ShapeMain extends JFrame{
	int x,y,x1,y1,x2,y2,width,height;
	boolean isFirstPoint = true;
	//初始化开始画的是线
	int drawType = PaintingGround.LINE;
	//初始化开始不是填充
	boolean isFill = false;
	
	ButtonGroup btg = new ButtonGroup();
	JRadioButton btLine = new JRadioButton("线",true);
	JRadioButton btRectangle = new JRadioButton("矩形");
	JRadioButton btRound = new JRadioButton("圆");
	JRadioButton btEllipse = new JRadioButton("椭圆");
	JToggleButton tbFillState = new JToggleButton("填充");
	
	JPanel buttonPanel = new JPanel();
	PaintingGround paintingGround = new PaintingGround();
	//Main Method
	public static void main(String[] args) {
		//设置显示外观
		try{
			UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
		}catch(Exception e) {
			e.printStackTrace();
		}
		new ShapeMain();
	}
	
	//构造函数
	public ShapeMain() {
		btg.add(btLine);
		btg.add(btRectangle);
		btg.add(btRound);
		btg.add(btEllipse);
		
		buttonPanel.add(btLine);
		buttonPanel.add(btRectangle);
		buttonPanel.add(btRound);
		buttonPanel.add(btEllipse);
		buttonPanel.add(tbFillState);
		
		Container cp = this.getContentPane();
		cp.setLayout(new BorderLayout());
		cp.add(BorderLayout.NORTH,buttonPanel);
		cp.add(BorderLayout.CENTER,paintingGround);
		
		setLocation(300,150);
		setSize(600,480);
		setVisible(true);
		setDefaultCloseOperation(EXIT_ON_CLOSE);
		
		paintingGround.addMouseListener(new MouseAdapter() {
				public void mouseReleased(MouseEvent evn) {
						isFirstPoint = true;
				}
			});
			
		paintingGround.addMouseMotionListener(new MouseMotionAdapter() {
				public void mouseDragged(MouseEvent evn) {
					if(isFirstPoint) {
						x1 = evn.getX();
						y1 = evn.getY();
						isFirstPoint = false;		
					}
					else {
						x2 = evn.getX();
						y2 = evn.getY();
						switch(drawType) {
							case PaintingGround.LINE:
								//画线
								paintingGround.drawLine(x1,y1,x2,y2);
								break;
							case PaintingGround.RECTANGLE:
								//画矫形
								paintingGround.drawRect(x1,y1,x2-x1,y2-y1);
								break;
							case PaintingGround.ROUND:
								//画圆
								//两点距离公式
								int size = Math.abs((int)Math.sqrt((x2-x1)*(x2-x1) + (y2-y1)*(y2-y1)));
								paintingGround.drawRound(x1,y1,size);
								break;
							case PaintingGround.ELLIPSE:
								//画椭圆
								paintingGround.drawEllipse(x1,y1,x2-x1,y2-y1);
								break;
							default:
								break;
						}
					}
				}
			});
			
		 btLine.addActionListener(new ActionListener(){
		 		public void actionPerformed(ActionEvent evn) {
		 			drawType = PaintingGround.LINE;
		 		}
		 	});
		 
		 btRectangle.addActionListener(new ActionListener(){
		 		public void actionPerformed(ActionEvent evn) {
		 			drawType = PaintingGround.RECTANGLE;
		 		}
		 	});
		 
		 btRound.addActionListener(new ActionListener(){
		 		public void actionPerformed(ActionEvent evn) {
		 			drawType = PaintingGround.ROUND;
		 		}
		 	});
		 
		 btEllipse.addActionListener(new ActionListener(){
		 		public void actionPerformed(ActionEvent evn) {
		 			drawType = PaintingGround.ELLIPSE;
		 		}
		 	});
		 
		 tbFillState.addActionListener(new ActionListener(){
		 		public void actionPerformed(ActionEvent evn) {
		 			isFill = tbFillState.isSelected();
		 			paintingGround.setFillState(isFill);
		 		}
		 	});
	}
}

class PaintingGround extends JPanel {
	public static final int LINE = 1;
	public static final int RECTANGLE = 2;
	public static final int ROUND = 3;
	public static final int ELLIPSE = 4;
	
	private int x,y;
	private int x1,y1,x2,y2;
	private int width, height,size;
	private int drawType = 0;
	private boolean isFill = false;
	//构造函数
	public PaintingGround() {
		setBackground(Color.lightGray);
	}
	
	public void paint(Graphics g) {
		super.paint(g);
		g.setColor(Color.red);
		if(isFill) {
			switch(drawType) {
				case LINE:
					g.drawLine(x1,y1,x2,y2);
					break;
				case RECTANGLE:
					g.fillRect(x,y,width,height);
					break;
				case ROUND:
					g.fillOval(x,y,size,size);
					break;
				case ELLIPSE:
					g.fillOval(x,y,width,height);
					break;
				default:
					break;
			}
		}
		else {
			switch(drawType) {
				case LINE:
					g.drawLine(x1,y1,x2,y2);
					break;
				case RECTANGLE:
					g.drawRect(x,y,width,height);
					break;
				case ROUND:
					g.drawOval(x,y,size,size);
					break;
				case ELLIPSE:
					g.drawOval(x,y,width,height);
					break;
				default:
					break;
			}
		}		
	}
	
	public void drawLine(int x1, int y1, int x2,int y2) {
		this.x1 = x1;
		this.y1 = y1;
		this.x2 = x2;
		this.y2 = y2;
		
		drawType = LINE;
		repaint();
	}
	
	public void drawRect(int x,int y,int width, int height) {
		this.x = x;
		this.y = y;
		this.width = width;
		this.height = height;
		drawType = RECTANGLE;
		repaint();
	}
	
	public void drawRound(int x,int y,int size) {
		this.x = x;
		this.y = y;
		this.size = size;
		drawType = ROUND;
		repaint();
	}
	
	public void drawEllipse(int x,int y,int width,int height) {
		this.x = x;
		this.y = y;
		this.width = width;
		this.height = height;
		drawType = ELLIPSE;
		repaint();
	}
	
	public void setFillState(boolean isFill) {
		this.isFill = isFill;
	}
	
}