paint.java

来自「java应用举例3」· Java 代码 · 共 106 行

import java.applet.*;
import java.awt.*;
import java.awt.event.*;
public class Paint extends Applet implements ItemListener, java.awt.Paint { 
    //声明组件
	Checkbox  box1,box2,box3,box4,box5,box6;
    CheckboxGroup xBox,yBox; 
    Label   label;
	//定义图形标志位和颜色标志位
	int  flag,color;
	public void init()	{ 
	    //初始化小应用程序
		color= 0;
		flag = 0;
		xBox = new CheckboxGroup();
		box1 = new Checkbox("画直线",false,xBox);
		box2 = new Checkbox("画矩形",false,xBox);
		box3 = new Checkbox("画圆形",false,xBox);
		yBox = new CheckboxGroup();
		box4 = new Checkbox("蓝色", false,yBox);
		box5 = new Checkbox("红色", false,yBox);
		box6 = new Checkbox("绿色", false,yBox);
		label= new Label("下面是画板",Label.CENTER);
		//设为空布局
		setLayout(null);
		//添加各种组件
		add(box1);
		add(box2);
		add(box3);
		add(box4);
		add(box5);
		add(box6);
		add(label);
		//设置各组件位置
		box1.setBounds(0,0,60,30);
		box2.setBounds(60,0,60,30);
		box3.setBounds(120,0,60,30);
		box4.setBounds(0,30,60,30);
		box5.setBounds(60,30,60,30);
		box6.setBounds(120,30,60,30);
		label.setBounds(0,60,180,30);
		//向单选按钮添加监视器
		box1.addItemListener(this);
		box2.addItemListener(this);
		box3.addItemListener(this);
		box4.addItemListener(this);
		box5.addItemListener(this);
		box6.addItemListener(this);
	}
	public void itemStateChanged(ItemEvent e){
		if(e.getItemSelectable()==box1){
			//选择画直线
			flag=1;
			repaint();	
		} else if (e.getItemSelectable()==box2){
            //选择画矩形
			flag=2;
			repaint();
		} else if (e.getItemSelectable()==box3){
            //选择画圆形
			flag=3;
			repaint();
		} else if(e.getItemSelectable()==box4){
			//设置画笔颜色为蓝色
			color=1;
			repaint();	
		} else if (e.getItemSelectable()==box5){
            //设置画笔颜色为红色
			color=2;
			repaint();
		} else if (e.getItemSelectable()==box6){
            //设置画笔颜色为绿色
			color=3;
			repaint();
		}

	}
	
	public void start(){
	}
	public void stop(){
	}
	public void paint(Graphics g){
		if(color==1){
			g.setColor(Color.blue);
		} else if(color==2) {
			g.setColor(Color.red);
		} else if(color==3) {
			g.setColor(Color.green);
		}
		if(flag==1){
		    //画直线
			g.drawLine(70,150,100,180);
		} else if(flag==2) {
		    //画矩形
			g.drawRect(70,150,30,30);
		} else if(flag==3) {
		    //画圆形
			g.drawRoundRect(70,150,30,30,30,30);
		}
	}
		 
}