drawpanel.java

用JAVA实现。一个简单的画图软件。可以进行简单的操作。还可以实现简单的图形绘画。如三角形等。

package DrawPlat;

import javax.swing.*;
import java.awt.*;
 class DrawPanel extends JPanel{
	
	 private DrawPlat mdp;
	 private drawings[] itemList;	  //用来存放基本图形的数组
	 private int index ;
	 Image offScreenImage = null;
	
	public DrawPanel(DrawPlat mdp) {
		
		this.mdp = mdp;
		this.setSize(mdp.WIDTH, mdp.HEIGHT);
		index = mdp.index;
		itemList = mdp.itemList;
		this.setCursor(Cursor.getPredefinedCursor(Cursor.CROSSHAIR_CURSOR));
		this.setBackground(Color.white);
		this.addMouseListener(new mouseA(mdp));
		this.addMouseMotionListener(new mouseB(mdp));

		new Thread( new PaintThread()).start();
	} 

	private class PaintThread extends Thread {

		
		public void run() {
			while(true) {
				paintComponent(mdp.drawingArea.getGraphics());
				repaint();
	//			mdp.repaint();
				try {
					Thread.sleep(50);
				} catch (InterruptedException e) {
					// TODO 自动生成 catch 块
				e.printStackTrace();
				} catch(NullPointerException npe) {
					
				} catch(Exception ee) {
					
					
				}
			}
			
		} //run
		
	} //PaintThread	


	public void paintComponent(Graphics g) {
		super.paintComponent(g);
		
		Graphics2D g2d = (Graphics2D)g; //定义画笔
		
		int j = 0;
		while(j <= index) {
			draw(g2d,itemList[j]);
			
			j++;
			
			
		}
	   	
		
	}
	

	
	void draw(Graphics2D g2d,drawings i){
		i.draw(g2d);
	}
	
}//DrawPanel