drawandview.java

自己做一个画板 可以画直线简单图形等 还能选择浏览图片等

        fbutton.setActionCommand("Free");//添加工具栏中的空白域,使图形选择和颜色选择分开
		buttonPane.addSeparator();//分隔线
		buttonPane.addSeparator();
		JButton cbutton=new JButton("颜色");//将颜色选项添加到工具栏中
	    buttonPane.add(cbutton);
		cbutton.addActionListener(new ActionListener()//匿名内部类事件处理
			{
				public void actionPerformed(ActionEvent event)
                {
					color = JColorChooser.showDialog(drawAndViewPanel.this,"select a new color...",color);
			     }});
		cbutton.setActionCommand("Color");
        ButtonGroup group = new ButtonGroup();
        fill = new JRadioButton("实心",false);//将实心还是空心按钮添加到工具栏中
        fill.addActionListener(new ActionListener()
		    {
				public void actionPerformed(ActionEvent event)
                {  isFill = true;  }
			});
		group.add(fill);
		buttonPane.add(fill);
		draw = new JRadioButton("空心",true);
		draw.addActionListener(new ActionListener()
			{
				public void actionPerformed(ActionEvent event)
                {
					isFill = false;
			     }});
        group.add(draw);
		buttonPane.add(draw);
		add(buttonPane,"North");//置边框布局北方
		toDraw=1;
     	fill.setEnabled(false);
     	draw.setEnabled(false);
		drawField =new drawAndViewField();//新建一个画图的区域
		add(drawField,"Center");//置边框布局中央
	 }
     public void actionPerformed(ActionEvent event)//按钮的事件处理
     {
     	String a=event.getActionCommand();
     	if (a.equals("Line"))	 toDraw=1;
     	else if (a.equals("Ellipse")) toDraw=2;
     	else if (a.equals("Rectangle")) toDraw=3;
		else if (a.equals("Free")) toDraw=4;
		else toDraw=1;
     	if (toDraw==1||toDraw==4)//若是画直线或是自由画就屏蔽掉实心或空心的按钮
     	{
			  fill.setEnabled(false);
     	      draw.setEnabled(false);
		 }
		 else
		 {
			 fill.setEnabled(true);
     	     draw.setEnabled(true);
		 }
     }
     public void newImage()
     {
		 drawField.drawlist.clear();//数组清零
		 drawField.backgrand=null;
		 drawField.repaint();//重绘图
	 }
	 public void openImage(ArrayList<VImage> a,Image i)
	 {
		 newImage();
		 if(a!=null)
		 drawField.drawlist=a;
		 drawField.backgrand=i;
		 if(i!=null)
		 System.out.println("加载图片");
	 }
	 public ArrayList getImageArray()
	 {
		 return drawField.drawlist;
	 }
	 public Image getBackgrand()
	 {
		 return drawField.backgrand;
	 }
	 public BufferedImage getPicture()
	 {
         BufferedImage  bufferImage = new BufferedImage(drawField.getWidth(),drawField.getHeight(),BufferedImage.TYPE_INT_RGB) ;
         Graphics buffer= bufferImage.createGraphics();
		 Graphics2D buffer2=(Graphics2D)buffer;
		 buffer2.setPaint(Color.WHITE);
		 buffer2.fill(new Rectangle2D.Double(0,0,getWidth(),getHeight()));
		 buffer2.setPaint(Color.BLACK);
   	     if(drawField.backgrand!=null)
   	       buffer2.drawImage(drawField.backgrand,0,0,this);
		 drawField.paintMap(buffer2);
		return bufferImage;
	}
    private class KeyHandler extends KeyAdapter//对键盘事件的处理方法
    {
		public void keyPressed(KeyEvent event)
			 {
				isSquare = event.isAltDown();//如果Alt被按下,则是画正方形或者圆形
			 	if(event.isControlDown()&&event.getKeyCode()==KeyEvent.VK_Z)//当按下Ctrl+Z则取消上一次的操作
			 	     drawField.removeEle();//调用removeEle方法
				}
		public void keyReleased(KeyEvent event)
			 {
			 	isSquare = event.isAltDown();//如果Alt被按下则画正方形
			  }
   }
   //画板域
    private class drawAndViewField extends JPanel implements MouseListener,MouseMotionListener
    {
   	    public ArrayList<VImage> drawlist=new ArrayList();//建立数组
   	    public VImage a;
   	    public boolean isPaint=false;
   	    public Image backgrand=null;
		public drawAndViewField()
   	    {
   	    	setBackground(new Color(255,255,255));//背景颜色
   	    	addMouseListener(this);
   	    	addMouseMotionListener(this);
   	    	addKeyListener(new KeyHandler());//添加键盘事件处理
		    setFocusable(true);
   	    }
   	   public void removeEle()//取消操作的处理
   	    {
			int i=drawlist.size();
			if (i>0)
			{
				drawlist.remove(i-1);
			    repaint();
			}
		}
   	    public void paintComponent(Graphics g)//绘图方法
   	    {
   	    	super.paintComponent(g);
   	    	Graphics2D g2=(Graphics2D)g;//强制类型转换
   	     	if(backgrand!=null)
   	       		g2.drawImage(backgrand,0,0,this);
			paintMap(g2);
   	    }
   	    public Graphics2D paintMap(Graphics2D g2)
   	    {
			g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,RenderingHints.VALUE_ANTIALIAS_ON);
			g2.setPaint(Color.WHITE);
   	    	if(backgrand!=null)
   	    	  g2.drawImage(backgrand,0,0,this);
   	    	else g2.fill(new Rectangle2D.Double(0,0,getWidth(),getHeight()));
   	    	g2.setPaint(Color.BLACK);
   	    	for(int i=0;i<drawlist.size();i++)
   	    	{
   	    		(drawlist.get(i)).draw(g2);
   	    	}
   	    	return g2;
		}
        public void rpaint(Graphics2D g2)
   	    {
            VImage i=(drawlist.get(drawlist.size()-1));

		    i.draw(g2);
	    }
	    //鼠标事件的处理抽象方法
        public void mousePressed(MouseEvent e)//抽象方法1
   	    {   isPaint=true;
			if (toDraw==4)
   	    	    a=new VImage(e.getX(),e.getY(),toDraw,color);//自由画不用考虑实心或空心
			 else
				a=new VImage(e.getX(),e.getY(),toDraw,color,isFill,isSquare);
			drawlist.add(a);
   	         setFocusable(true);
   	    }
		public void mouseReleased(MouseEvent e)//抽象方法2
   	    {
            isPaint=false;
            Graphics2D g2=(Graphics2D)getGraphics();
			repaint();}
   	    public void mouseClicked(MouseEvent e){}  //抽象方法3
   	    public void mouseMoved(MouseEvent e){}  //抽象方法4
   	    public void mouseDragged(MouseEvent e)//抽象方法5
   	    {
			Graphics2D g2=(Graphics2D)getGraphics();
   	    	Color color=getBackground();
			if (toDraw==4)
   	    	{
				p1=new Point2D.Double(e.getX(),e.getY());//建立2D点对象
				a.points.add(p1);
			}else
			{   g2.setXORMode(color);
				rpaint(g2);
				a.compare();
				a.isSquare=isSquare;
				a.ly=e.getY();
   	    	    a.lx=e.getX();
   	    	}
		rpaint(g2);//绘制图形
   	    }
   	    public void mouseExited(java.awt.event.MouseEvent e){} //抽象方法6
   	    public void mouseEntered(java.awt.event.MouseEvent e)//抽象方法7
   	    {
			requestFocusInWindow();
		}
	}
 }
 class VImage implements Serializable//图像类
 {
 	public int fx,fy,lx,ly;//坐标起始点和终止点
 	public int lu,ld;//图形左上方的点
 	public int length;//图形的宽
 	public int height;//图形的高
 	public int type;//图形类型
 	public boolean isFill=false;//是否填充
 	public ArrayList points;
 	public Color color;//图形颜色
 	public boolean isSquare;//是否是方形
	public VImage(int fx,int fy,int type,Color color ,boolean isFill,boolean isSquare)
 	{
		this.fx=fx;
		this.fy=fy;
		this.type=type;
		this.color=color;
		this.isFill=isFill;
		this.isSquare=isSquare;
		lx=fx;
		ly=fy;
 	}
	public VImage(int x,int y,int type,Color color)
 	{
		this.type=type;
		this.color=color;
		points=new ArrayList();
		points.add(new Point2D.Double(x,y));
	}
   public void draw(Graphics2D g2)//绘图方法
 	{
        g2.setPaint(color);
 		g2.setStroke(new BasicStroke(2,BasicStroke.CAP_ROUND,BasicStroke.JOIN_MITER));
 		if (isFill)
 		    switch (type){
					case 1: g2.draw(new Line2D.Double(fx,fy,lx,ly)); break;//直线
		 		    case 2: g2.fill(new Ellipse2D.Double(lu,ld,length,height));break;//椭圆
					case 3: g2.fill(new Rectangle2D.Double(lu,ld,length,height));break;//矩形
		 		    case 4: for(int i=0;i<points.size()-1;i++)
		    	              g2.draw(new Line2D.Double((Point2D)points.get(i),(Point2D)points.get(i+1)));break;
		    	        }
 		else
 		  switch (type){
	    		case 1: g2.draw(new Line2D.Double(fx,fy,lx,ly)); break;
 		        case 2: g2.draw(new Ellipse2D.Double(lu,ld,length,height));break;
				case 3: g2.draw(new Rectangle2D.Double(lu,ld,length,height));break;
 		        case 4: for(int i=0;i<points.size()-1;i++)
    	              g2.draw(new Line2D.Double((Point2D)points.get(i),(Point2D)points.get(i+1)));break;
                }
    }
	public void compare()//处理坐标
    {
		 length = Math.abs(lx-fx);
		 height = Math.abs(ly-fy);
		 if (isSquare)
		 {
		 		if (height>length)
		 			height = length;
		 		else length=height;
		 }//是方形时宽和高相等
		 if (lx>fx)
		 {
			  lu=fx;
		 }
		 else
		 {
			 lu=fx-length;
		 }
		 if(ly>fy)
		 {
			 ld=fy;
		 }
		 else
		 {
			 ld=fy-height;
		 }
	}
 }
public class drawAndView
{//主方法
 	public static void main(String args[]) {
 		System.out.println("Starting Draw...");
 		drawAndViewFrame mainFrame = new drawAndViewFrame();//构造方法
 		mainFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
 		mainFrame.setVisible(true);//jdk1.5用mainFrame.setVisible代替
	}
}