drawboard.java

java画图程序. 能完成大多数的功能.

/**画板类。初始化画板，捕捉鼠标事件。
 * 由454zhx编写 。May 20th
 */
package cn.edu.xmu.LHand;
import javax.swing.*;
import java.awt.event.*;
import java.awt.*;
import java.awt.Graphics;
import java.util.ArrayList;
/**
 * 
 * @author Administrator
 *昏迷 怎么用啊
 */
public class DrawBoard extends JPanel implements 
	MouseListener,MouseMotionListener{
	
	public static int buttonPressed = 0;
	public static final Stroke[] STROKES = new Stroke[]{
        new BasicStroke(1.0f),
        new BasicStroke(2.0f),
        new BasicStroke(5.0f),
        new BasicStroke(7.5f),
        new BasicStroke(10.0f)
    };
	public static float strokeIndex = 0; 				//指定选择的粗细
	public static IShape currentShape = null;			//用来指向继承他的各个子类
	public static ArrayList IShapes = null;			//存放画过的图 
	public static String strings;
	
	public DrawBoard(){
		
		IShapes = new ArrayList();
		addMouseListener(this);
		addMouseMotionListener(this);
		
		
		setDoubleBuffered(true);                                   //设置双缓冲
		setCursor(new Cursor(Cursor.CROSSHAIR_CURSOR));            //设置鼠标样式
		this.setPreferredSize((new Dimension(700,600)));          //设置工作区域
		this.setBorder(BorderFactory.createRaisedBevelBorder());  //设置边框
		this.setForeground(Color.BLACK);
		this.setBackground(Color.WHITE);
		setVisible(true);
	}
	
	public void clearBoard(){
		IShapes.clear();
		currentShape = null;
		repaint();
	}
	
	public void paintComponent(Graphics g){
		super.paintComponent(g);
		
		int i = IShapes.size();
		Graphics2D g2D = (Graphics2D) g;
		for(int j=0; j<i; j++){
			((IShape)IShapes.get(j)).draw(g2D);
		}
	}
	
    public void mousePressed(MouseEvent event){
    	Drawer.statusBar.setText("                               |"
    			+event.getX()+","+event.getY()+"|");
    	
    	if(DrawBoard.buttonPressed == 0)
    		return;
    	else if(event.getButton() == MouseEvent.BUTTON1){
    		switch(buttonPressed){
    			case 1:
    				strings = JOptionPane.showInputDialog(this,"Enter the strings");
    				currentShape = new Word(getForeground(), strokeIndex,
    						event.getX(), event.getY());
    				break;
    			case 2:
    				currentShape = new Line(getForeground(), strokeIndex,
    						event.getX(), event.getY());
    				break;
    			case 3:
    				currentShape = new Rect(getForeground(), strokeIndex,
    						event.getX(), event.getY());
    				break;
    			case 4:
    				currentShape = new RoundRect(getForeground(), strokeIndex,
    						event.getX(), event.getY());
    				break;
    			case 5:
    				currentShape = new Oval(getForeground(), strokeIndex,
    						event.getX(), event.getY());
    				break;
    			case 6:
    				if(currentShape == null)
    					currentShape = new Polygon(getForeground(), strokeIndex,
    							event.getX(), event.getY());
    				else{
    					currentShape.mousePressed(event);
    					repaint();
    					return;
    				}
    				break;
    			case 7:
    				currentShape = new PaintBrush(getForeground(), strokeIndex,
       						event.getX(), event.getY());
    				break;
       			case 8:
       				currentShape = new PolyLine(getForeground(), strokeIndex,
       						event.getX(), event.getY());
       				break;
       			case 9:
       				currentShape = new Eraser(getBackground(),strokeIndex,
       						event.getX(), event.getY());
       				break;
    			default: 
    				break;
    		}
    		
    	if(currentShape != null){
    		IShapes.add(currentShape);
    		repaint();
    		}
    	}
    	else 
			return;
    }
    
    public void mouseDragged(MouseEvent event){
    	
    	Drawer.statusBar.setText("                               |"
    			+event.getX()+","+event.getY()+"|");
    	
    	if(currentShape == null)
    		return;
    	
    	currentShape.mouseDragged(event);
    	repaint();
    }
    
    public void mouseReleased(MouseEvent event){
    	//这里无法判断什么时候 多边形绘画结束。 = =~！
    	if(currentShape != null && buttonPressed == 6){
    		currentShape.mouseReleased(event);
    		repaint();
    	}
    	else
    		currentShape = null;
    	return;
    }
    /*public static  void nullPolygonShape(){
    	currentShape = null;
    }*/
    public void mouseClicked(MouseEvent event){}
    public void mouseEntered(MouseEvent event){}
    public void mouseExited(MouseEvent event){
    	Drawer.statusBar.setText("                               |"+"       |");
    }
    public void mouseMoved(MouseEvent event){
    	Drawer.statusBar.setText("                               |"
    			+event.getX()+","+event.getY()+"|");
    	
    }
}