java画图板代码原理 java实现画板

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GUI画图板（绘图板）设计，用Java编写程序代码！！谢谢！！

只有矩形有圆形能移动，其它实现起来麻烦点，办法有的只是代码太多。

画圆弧改成了画曲线，圆弧稍麻烦，当然方法是很简单的，你可以自己思考一下。

双击13个颜色中的任意一个都会弹出颜色选择器。

有保存与打开功能。扩展名请用 .jdr

基本满足条件，细节可能不是很好，另，代码比较乱，怕不好看懂咯，呼呼。

import java.awt.*;

import java.awt.event.*;

import java.awt.geom.*;

import java.awt.image.BufferedImage;

import java.io.*;

import java.util.ArrayList;

import javax.swing.*;

import javax.swing.filechooser.FileNameExtensionFilter;

public class JDraw {

public static void main(String[] args) {

JFrame f=new JFrame();

f.setDefaultCloseOperation(3);

f.setSize(880,600);

f.setLocationRelativeTo(null);

f.getContentPane().add(M.c);

f.getContentPane().add(M.m,"South");

f.setVisible(true);

}

class CVS extends Component implements ComponentListener,MouseListener,MouseMotionListener{

public void componentHidden(ComponentEvent e) {}

public void componentMoved(ComponentEvent e) {}

public void componentResized(ComponentEvent e) {resized();}

public void componentShown(ComponentEvent e) {}

private void resized() {

int w=this.getWidth();

int h=this.getHeight();

tbuff=new BufferedImage(w,h,3);

makeBuff(w,h);

}

private void makeBuff(int w,int h) {

Graphics g = tbuff.getGraphics();

g.drawImage(buff,0,0,null);

g.dispose();

buff=new BufferedImage(w,h,3);

g=buff.getGraphics();

g.drawImage(tbuff,0,0,null);

g.dispose();

}

BufferedImage buff,tbuff;

CVS(){

this.addComponentListener(this);

this.addMouseListener(this);

this.addMouseMotionListener(this);

buff=new BufferedImage(1,1,3);

}

public void paint(Graphics gr){

Graphics2D g = buff.createGraphics();

g.setBackground(new Color(0xff000000,true));

g.clearRect(0,0,getWidth(),getHeight());

g.setRenderingHint(RenderingHints.KEY_ANTIALIASING,

RenderingHints.VALUE_ANTIALIAS_ON);

M.sa.drawAll(g);

if(M.ts!=null)

M.ts.draw(g);

g.dispose();

gr.drawImage(buff,0,0,this);

gr.dispose();

}

public void mouseClicked(MouseEvent e) {}

public void mouseEntered(MouseEvent e) {}

public void mouseExited(MouseEvent e) {}

public void mousePressed(MouseEvent e) {

M.mp(e.getPoint());

}

public void mouseReleased(MouseEvent e) {

M.mr(e.getPoint());

}

public void mouseDragged(MouseEvent e) {

M.md(e.getPoint());

}

public void mouseMoved(MouseEvent e) {}

}

class Menu extends JComponent implements MouseListener,ActionListener{

JComboBox sbox,method;

CLabel[] cl;

JCheckBox fillC,drawB;

JRadioButton fc,bc;

ButtonGroup bg;

JButton clear,up,down,save,load;

Menu(){

this.setLayout(new FlowLayout());

method=new JComboBox(new Object[]{"draw","move","erase",});

add(method);

sbox=new JComboBox(new Object[]{"Pt","Ln","Rect","Cir","Arc",});

add(sbox);

cl=new CLabel[13];

for(int i=0; icl.length; i++){

cl[i]=new CLabel();

cl[i].addMouseListener(this);

add(cl[i]);

}

fc=new JRadioButton("fc",true);

bc=new JRadioButton("bc");

bg=new ButtonGroup();

bg.add(fc);bg.add(bc);

add(fc);add(bc);

fc.setOpaque(true);

bc.setOpaque(true);

fc.setBackground(Color.white);

bc.setBackground(Color.blue);

fillC=new JCheckBox("Fill",true);

drawB=new JCheckBox("Draw",true);

fillC.addActionListener(this);

drawB.addActionListener(this);

add(fillC);add(drawB);

clear=new JButton("clear");

clear.addActionListener(this);

add(clear);

up=new JButton("zUp");

up.addActionListener(this);

add(up);

down=new JButton("zDown");

down.addActionListener(this);

add(down);

save=new JButton("Save");

save.addActionListener(this);

add(save);

load=new JButton("Load");

load.addActionListener(this);

add(load);

}

public void mouseClicked(MouseEvent e) {

JLabel l=(JLabel)e.getSource();

if(e.getClickCount()==2){

Color sc=JColorChooser.showDialog(null, "Color chooser", l.getBackground());

l.setBackground(sc);

mousePressed(e);

}

public void mouseEntered(MouseEvent e) {}

public void mouseExited(MouseEvent e) {}

public void mousePressed(MouseEvent e) {

Color c=((JLabel)e.getSource()).getBackground();

if(fc.isSelected())

fc.setBackground(c);

else if(bc.isSelected())

bc.setBackground(c);

M.cp();

}

public void mouseReleased(MouseEvent e) {}

public void actionPerformed(ActionEvent e) {

if(e.getSource()==clear)M.clear();

else if(e.getSource()==up)M.up();

else if(e.getSource()==down)M.down();

else if(e.getSource()==save)M.save();

else if(e.getSource()==load)M.load();

else if(e.getSource()==fillC||e.getSource()==drawB)M.cp();

}

class CLabel extends JLabel{

static Color[] cs={Color.red,Color.orange,Color.yellow,Color.green,Color.cyan,

Color.blue,Color.magenta,Color.magenta.brighter(),

Color.white,Color.black,Color.gray,Color.LIGHT_GRAY,Color.DARK_GRAY,};

static int i;

CLabel(){

this.setOpaque(true);

this.setBackground(cs[i++]);

this.setBorder(BorderFactory.createLineBorder(Color.black));

this.setPreferredSize(new Dimension(10,20));

}

class M{

static JFileChooser jfc=new JFileChooser();

static Menu m=new Menu();

static CVS c=new CVS();

static SA sa=new SA();

static S ts=null,selected=null;

static Color fc,bc;

static void clear(){

sa.ss.clear();

c.repaint();

}

public static void cp() {

System.out.println(selected);

if(selected!=null){

selected.fillColor=m.fc.getBackground();

selected.borderColor=m.bc.getBackground();

selected.fc=m.fillC.isSelected();

selected.db=m.drawB.isSelected();

c.repaint();

}

public static void up() {

if(selected!=null){

sa.upZ(selected);

c.repaint();

}

public static void down(){

if(selected!=null){

sa.downZ(selected);

c.repaint();

}

static{

jfc.setFileFilter(new FileNameExtensionFilter("JDraw file (*.jdraw,*.jdr)","jdr","jdraw"));

}

static void save(){

int x=jfc.showSaveDialog(c);

if(x==JFileChooser.APPROVE_OPTION){

File f = jfc.getSelectedFile();

try{

ObjectOutputStream oos=new ObjectOutputStream(new FileOutputStream(f));

oos.writeObject(sa);

oos.flush();

oos.close();

}catch(Exception e){}

}

static void load(){

int x=jfc.showOpenDialog(c);

if(x==JFileChooser.APPROVE_OPTION){

File f = jfc.getSelectedFile();

try{

ObjectInputStream oos=new ObjectInputStream(new FileInputStream(f));

Object r=oos.readObject();

if(r!=null){

sa=(SA)r;

c.repaint();

}

oos.close();

}catch(Exception e){e.printStackTrace();}

}

static int mx,my,tx,ty,ox,oy;

static int pc=0,pmax;

static int sm;

static boolean ne=true;

static int mid;

static void mp(Point p){

mid=m.method.getSelectedIndex();

if(mid==0){

if(ne){

mx=p.x;my=p.y;

pc=0;

sm=m.sbox.getSelectedIndex();

pmax=sm==4?2:1;

ne=false;

}

++pc;

}

else if(mid==1){

checkSel(p);

mx=p.x;my=p.y;

}

else if(mid==2){

checkSel(p);

if(selected!=null){

sa.ss.remove(selected);

c.repaint();

}

private static void checkSel(Point p) {

selected=null;

for(int i=sa.ss.size();i0; i--)

if(sa.ss.get(i-1).shape.contains(p)){

selected=sa.ss.get(i-1);break;

}

sa.select(selected);

c.repaint();

}

static void mt(){

Shape s=null;

int cx,cy,cw,ch;

switch(sm){

case 0:

case 2:

cx=Math.min(mx,tx);

cy=Math.min(my,ty);

cw=Math.abs(mx-tx);

ch=Math.abs(my-ty);

if(sm==0)

s=new Ellipse2D.Double(cx,cy,cw,ch);

else

s=new Rectangle(cx,cy,cw,ch);

break;

case 1:

s=new Line2D.Float(mx,my,tx,ty);

break;

case 3:

cw=Math.abs(mx-tx);

ch=Math.abs(my-ty);

int cd=(int)Math.sqrt(Math.pow(mx-tx,2)+Math.pow(my-ty,2))*2;

cx=mx-cd/2;

cy=my-cd/2;

s=new Ellipse2D.Double(cx,cy,cd,cd);

break;

case 4:

Path2D p=new Path2D.Double();

p.moveTo(mx,my);

if(pc==1){

p.lineTo(tx, ty);

}

else{

p.quadTo(ox,oy,tx,ty);

}

s=p;

break;

}

ts=new S(s,m.fc.getBackground(),m.bc.getBackground(),m.fillC.isSelected(),m.drawB.isSelected(),null);

c.repaint();

}

static void md(Point p){

if(mid==0){

if(!sa.ss.isEmpty()){

sa.ss.get(sa.ss.size()-1).sel=false;

}

if(pc1){

ox=p.x;oy=p.y;

}

else{

tx=p.x;ty=p.y;

}

mt();

}

else if(mid==1){

if(selected!=null){

moveTo(selected,p);

c.repaint();

}

else if(mid==2){

checkSel(p);

if(selected!=null){

sa.ss.remove(selected);

c.repaint();

}

static void moveTo(S s, Point p) {

if(s.shape instanceof Rectangle){

Rectangle r=(Rectangle)s.shape;

r.setLocation(r.x+p.x-mx,r.y+p.y-my);

mx=p.x;my=p.y;

}

else if(s.shape instanceof Ellipse2D){

Ellipse2D e=(Ellipse2D)s.shape;

e.setFrame(e.getX()+p.x-mx,e.getY()+p.y-my,e.getWidth(),e.getHeight());

mx=p.x;my=p.y;

}

static void mr(Point p) {

if(pc==pmax){

pc=0;

ne=true;

sa.add(ts);

selected=ts;

ts=null;

}

class S implements Serializable{

boolean fc,db,sel=true;

Shape shape;

Color fillColor,borderColor;

Stroke stroke;

static Stroke bstroke=new MyBasicStroke();

static Stroke selectStroke=new BasicStroke(1,BasicStroke.CAP_BUTT,BasicStroke.JOIN_MITER,1,new float[]{5,2},1);

S(Shape s,Color c,Color b,boolean f,boolean d,Stroke k){

this.shape=s;this.fillColor=c;this.borderColor=b;this.fc=f;this.db=d;this.stroke=k==null?bstroke:k;

}

void draw(Graphics2D g){

if(fc){

g.setColor(fillColor);

g.fill(shape);

}

if(db){

g.setColor(borderColor);

g.setStroke(stroke);

g.draw(shape);

}

if(sel){

g.setColor(Color.green);

g.setStroke(selectStroke);

g.draw(shape.getBounds());

}

class MyBasicStroke extends BasicStroke implements Serializable{}

class SA implements Serializable{

ArrayListS ss=new ArrayListS();

void add(S s){

if(s!=null){

for(S sx:ss)

sx.sel=false;

ss.add(s);

}

S remove(int i){

return ss.remove(i);

}

void remove(S s){

ss.remove(s);

}

void upZ(S s){

indexZ(s,1);

}

void downZ(S s){

indexZ(s,-1);

}

void indexZ(S s, int i) {

int si=ss.indexOf(s);

if(si+i0||si+iss.size()-1)return;

swap(s,ss.get(si+i));

}

void swap(S a,S b){

int ai=ss.indexOf(a);

int bi=ss.indexOf(b);

ss.set(ai,b);

ss.set(bi,a);

}

void select(S s){

for(S x:ss)

x.sel=false;

if(s!=null)

s.sel=true;

}

void drawAll(Graphics2D g){

for(S s:ss)

s.draw(g);

}

相关问答

Q1: 求java版画图程序的源代码

找到java画图板代码原理了java画图板代码原理，很久以前写的一个简单画图，呵呵～当时要求用AWT写，很难受。

package net.miqiang.gui;

import java.awt.BasicStroke;

import java.awt.BorderLayout;

import java.awt.Button;

import java.awt.Color;

import java.awt.Cursor;

import java.awt.Dimension;

import java.awt.Frame;

import java.awt.Graphics;

import java.awt.Graphics2D;

import java.awt.GridLayout;

import java.awt.Label;

import java.awt.Panel;

import java.awt.RenderingHints;

import java.awt.Toolkit;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.awt.event.MouseAdapter;

import java.awt.event.MouseEvent;

import java.awt.event.MouseListener;

import java.awt.event.MouseMotionListener;

import java.awt.event.WindowAdapter;

import java.awt.event.WindowEvent;

import java.awt.image.BufferedImage;

/**

* 简单画图板程序

* 好久没用 AWT java画图板代码原理了，写起来真别扭，如果用 swing 会很舒服，有空再改写吧。

* @author 米强

public class TestMain extends Frame {

// 画板

private Palette palette = null;

// 显示当前颜色的面板

private Panel nonceColor = null;

// 画笔粗细

private Label drawWidth = null;

// 画笔端点的装饰

private Label drawCap = null;

// 选取颜色按钮的监听事件类

private ButtonColorAction buttonColorAction = null;

// 鼠标进入按钮后光标样式的监听事件类

private ButtonCursor buttonCursor = null;

// 画笔样式的监听事件

private ButtonStrokeAction buttonStrokeAction = null;

/**

* 构造方法

public TestMain() {

// 设置标题栏文字

super("简易画图板");

// 构造一个画图板

palette = new Palette();

Panel pane = new Panel(new GridLayout(2, 1));

// 画笔颜色选择器

Panel paneColor = new Panel(new GridLayout(1, 13));

// 12 个颜色选择按钮

Button [] buttonColor = new Button[12];

Color [] color = {Color.black, Color.blue, Color.cyan, Color.darkGray, Color.gray, Color.green, Color.magenta, Color.orange, Color.pink, Color.red, Color.white, Color.yellow};

// 显示当前颜色的面板

nonceColor = new Panel();

nonceColor.setBackground(Color.black);

paneColor.add(nonceColor);

buttonColorAction = new ButtonColorAction();

buttonCursor = new ButtonCursor();

for(int i = 0; i buttonColor.length; i++){

buttonColor[i] = new Button();

buttonColor[i].setBackground(color[i]);

buttonColor[i].addActionListener(buttonColorAction);

buttonColor[i].addMouseListener(buttonCursor);

paneColor.add(buttonColor[i]);

}

pane.add(paneColor);

// 画笔颜色选择器

Panel paneStroke = new Panel(new GridLayout(1, 13));

// 控制画笔样式

buttonStrokeAction = new ButtonStrokeAction();

Button [] buttonStroke = new Button[11];

buttonStroke[0] = new Button("1");

buttonStroke[1] = new Button("3");

buttonStroke[2] = new Button("5");

buttonStroke[3] = new Button("7");

buttonStroke[4] = new Button("9");

buttonStroke[5] = new Button("11");

buttonStroke[6] = new Button("13");

buttonStroke[7] = new Button("15");

buttonStroke[8] = new Button("17");

buttonStroke[9] = new Button("■");

buttonStroke[10] = new Button("●");

drawWidth = new Label("3", Label.CENTER);

drawCap = new Label("●", Label.CENTER);

drawWidth.setBackground(Color.lightGray);

drawCap.setBackground(Color.lightGray);

paneStroke.add(drawWidth);

for(int i = 0; i buttonStroke.length; i++){

paneStroke.add(buttonStroke[i]);

buttonStroke[i].addMouseListener(buttonCursor);

buttonStroke[i].addActionListener(buttonStrokeAction);

if(i = 8){

buttonStroke[i].setName("width");

}else{

buttonStroke[i].setName("cap");

}

if(i == 8){

paneStroke.add(drawCap);

}

pane.add(paneStroke);

// 将画笔颜色选择器添加到窗体中

this.add(pane, BorderLayout.NORTH);

// 将画图板添加到窗体中

this.add(palette);

// 添加窗口监听，点击关闭按钮时退出程序

this.addWindowListener(new WindowAdapter() {

public void windowClosing(WindowEvent e) {

System.exit(0);

}

});

// 设置窗体 ICON 图标

this.setIconImage(Toolkit.getDefaultToolkit().createImage("images/palette.png"));

// 设置窗口的大小

this.setSize(new Dimension(400, 430));

// 设置窗口位置，处于屏幕正中央

this.setLocationRelativeTo(null);

// 显示窗口

this.setVisible(true);

}

/**

* 程序入口

* @param args

* 字符串数组参数

public static void main(String[] args) {

new TestMain();

}

/**

* 选取颜色按钮的监听事件类

* @author 米强

class ButtonColorAction implements ActionListener {

public void actionPerformed(ActionEvent e) {

Color color_temp = ((Button)e.getSource()).getBackground();

nonceColor.setBackground(color_temp);

palette.setColor(color_temp);

}

/**

* 鼠标进入按钮变换光标样式监听事件类

* @author 米强

class ButtonCursor extends MouseAdapter {

public void mouseEntered(MouseEvent e) {

((Button)e.getSource()).setCursor(new Cursor(Cursor.HAND_CURSOR));

}

public void mouseExited(MouseEvent e) {

((Button)e.getSource()).setCursor(new Cursor(Cursor.DEFAULT_CURSOR));

}

/**

* 设置画笔的监听事件类

* @author 米强

class ButtonStrokeAction implements ActionListener {

public void actionPerformed(ActionEvent e) {

Button button_temp = (Button) e.getSource();

String name = button_temp.getName();

if(name.equalsIgnoreCase("width")){

drawWidth.setText(button_temp.getLabel());

palette.setStroke(Float.parseFloat(button_temp.getLabel()));

}else if(name.equalsIgnoreCase("cap")){

drawCap.setText(button_temp.getLabel());

if(button_temp.getLabel().equals("■")){

palette.setStroke(BasicStroke.CAP_SQUARE);

}else if(button_temp.getLabel().equals("●")){

palette.setStroke(BasicStroke.CAP_ROUND);

}

/**

* 画板类

* @author 米强

class Palette extends Panel implements MouseListener, MouseMotionListener {

// 鼠标 X 坐标的位置

private int mouseX = 0;

// 上一次 X 坐标位置

private int oldMouseX = 0;

// 鼠标 Y 坐标的位置

private int mouseY = 0;

// 上一次 Y 坐标位置

private int oldMouseY = 0;

// 画图颜色

private Color color = null;

// 画笔样式

private BasicStroke stroke = null;

// 缓存图形

private BufferedImage image = null;

/**

* 构造一个画板类

public Palette() {

this.addMouseListener(this);

this.addMouseMotionListener(this);

// 默认黑色画笔

color = new Color(0, 0, 0);

// 设置默认画笔样式

stroke = new BasicStroke(3.0f, BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND);

// 建立 1280 * 1024 的 RGB 缓存图象

image = new BufferedImage(1280, 1024, BufferedImage.TYPE_INT_RGB);

// 设置颜色

image.getGraphics().setColor(Color.white);

// 画背景

image.getGraphics().fillRect(0, 0, 1280, 1024);

}

/**

* 重写 paint 绘图方法

public void paint(Graphics g) {

super.paint(g);

// 转换为 Graphics2D

Graphics2D g2d = (Graphics2D) g;

// 获取缓存图形 Graphics2D

Graphics2D bg = image.createGraphics();

// 图形抗锯齿

bg.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);

// 设置绘图颜色

bg.setColor(color);

// 设置画笔样式

bg.setStroke(stroke);

// 画线，从上一个点到新的点

bg.drawLine(oldMouseX, oldMouseY, mouseX, mouseY);

// 将缓存中的图形画到画板上

g2d.drawImage(image, 0, 0, this);

}

/**

* 重写 update 方法

public void update(Graphics g) {

this.paint(g);

}

/**

* @return stroke

public BasicStroke getStroke() {

return stroke;

}

/**

* @param stroke 要设置的 stroke

public void setStroke(BasicStroke stroke) {

this.stroke = stroke;

}

/**

* 设置画笔粗细

* @param width

public void setStroke(float width) {

this.stroke = new BasicStroke(width, stroke.getEndCap(), stroke.getLineJoin());

}

/**

* 设置画笔端点的装饰

* @param cap 参考 java.awt.BasicStroke 类静态字段

public void setStroke(int cap) {

this.stroke = new BasicStroke(stroke.getLineWidth(), cap, stroke.getLineJoin());

}

/**

* @return color

public Color getColor() {

return color;

}

/**

* @param color 要设置的 color

public void setColor(Color color) {

this.color = color;

}

public void mouseClicked(MouseEvent mouseEvent) {

}

/**

* 鼠标按下

public void mousePressed(MouseEvent mouseEvent) {

this.oldMouseX = this.mouseX = mouseEvent.getX();

this.oldMouseY = this.mouseY = mouseEvent.getY();

repaint();

}

public void mouseReleased(MouseEvent mouseEvent) {

}

/**

* 鼠标进入棋盘

public void mouseEntered(MouseEvent mouseEvent) {

this.setCursor(new Cursor(Cursor.CROSSHAIR_CURSOR));

}

/**

* 鼠标退出棋盘

public void mouseExited(MouseEvent mouseEvent) {

this.setCursor(new Cursor(Cursor.DEFAULT_CURSOR));

}

/**

* 鼠标拖动

public void mouseDragged(MouseEvent mouseEvent) {

this.oldMouseX = this.mouseX;

this.oldMouseY = this.mouseY;

this.mouseX = mouseEvent.getX();

this.mouseY = mouseEvent.getY();

repaint();

}

public void mouseMoved(MouseEvent mouseEvent) {

}

Q2: java 实现简单画图功能(简单点的)

楼主给你一个我编的，直接保存成pb.java编译运行，就是你要的画图功能

____________________________________________________________________

import java.applet.*;

import java.awt.*;

import java.awt.event.*;

import java.util.*;

import javax.swing.*;

import java.awt.geom.*;

import java.io.*;

class Point implements Serializable

{

int x,y;

Color col;

int tool;

int boarder;

Point(int x, int y, Color col, int tool, int boarder)

{

this.x = x;

this.y = y;

this.col = col;

this.tool = tool;

this.boarder = boarder;

}

class paintboard extends Frame implements ActionListener,MouseMotionListener,MouseListener,ItemListener

{

int x = -1, y = -1;

int con = 1;//画笔大小

int Econ = 5;//橡皮大小

int toolFlag = 0;//toolFlag:工具标记

//toolFlag工具对应表：

//（0--画笔）；（1--橡皮）；（2--清除）；

//（3--直线）；（4--圆）；（5--矩形）；

Color c = new Color(0,0,0); //画笔颜色

BasicStroke size = new BasicStroke(con,BasicStroke.CAP_BUTT,BasicStroke.JOIN_BEVEL);//画笔粗细

Point cutflag = new Point(-1, -1, c, 6, con);//截断标志

Vector paintInfo = null;//点信息向量组

int n = 1;

FileInputStream picIn = null;

FileOutputStream picOut = null;

ObjectInputStream VIn = null;

ObjectOutputStream VOut = null;

// *工具面板--画笔，直线，圆，矩形，多边形,橡皮，清除*/

Panel toolPanel;

Button eraser, drLine,drCircle,drRect;

Button clear ,pen;

Choice ColChoice,SizeChoice,EraserChoice;

Button colchooser;

Label 颜色,大小B,大小E;

//保存功能

Button openPic,savePic;

FileDialog openPicture,savePicture;

paintboard(String s)

{

super(s);

addMouseMotionListener(this);

addMouseListener(this);

paintInfo = new Vector();

/*各工具按钮及选择项*/

//颜色选择

ColChoice = new Choice();

ColChoice.add("black");

ColChoice.add("red");

ColChoice.add("blue");

ColChoice.add("green");

ColChoice.addItemListener(this);

//画笔大小选择

SizeChoice = new Choice();

SizeChoice.add("1");

SizeChoice.add("3");

SizeChoice.add("5");

SizeChoice.add("7");

SizeChoice.add("9");

SizeChoice.addItemListener(this);

//橡皮大小选择

EraserChoice = new Choice();

EraserChoice.add("5");

EraserChoice.add("9");

EraserChoice.add("13");

EraserChoice.add("17");

EraserChoice.addItemListener(this);

////////////////////////////////////////////////////

toolPanel = new Panel();

clear = new Button("清除");

eraser = new Button("橡皮");

pen = new Button("画笔");

drLine = new Button("画直线");

drCircle = new Button("画圆形");

drRect = new Button("画矩形");

openPic = new Button("打开图画");

savePic = new Button("保存图画");

colchooser = new Button("显示调色板");

//各组件事件监听

clear.addActionListener(this);

eraser.addActionListener(this);

pen.addActionListener(this);

drLine.addActionListener(this);

drCircle.addActionListener(this);

drRect.addActionListener(this);

openPic.addActionListener(this);

savePic.addActionListener(this);

colchooser.addActionListener(this);

颜色 = new Label("画笔颜色",Label.CENTER);

大小B = new Label("画笔大小",Label.CENTER);

大小E = new Label("橡皮大小",Label.CENTER);

//面板添加组件

toolPanel.add(openPic);

toolPanel.add(savePic);

toolPanel.add(pen);

toolPanel.add(drLine);

toolPanel.add(drCircle);

toolPanel.add(drRect);

toolPanel.add(颜色); toolPanel.add(ColChoice);

toolPanel.add(大小B); toolPanel.add(SizeChoice);

toolPanel.add(colchooser);

toolPanel.add(eraser);

toolPanel.add(大小E); toolPanel.add(EraserChoice);

toolPanel.add(clear);

//工具面板到APPLET面板

add(toolPanel,BorderLayout.NORTH);

setBounds(60,60,900,600); setVisible(true);

validate();

//dialog for save and load

openPicture = new FileDialog(this,"打开图画",FileDialog.LOAD);

openPicture.setVisible(false);

savePicture = new FileDialog(this,"保存图画",FileDialog.SAVE);

savePicture.setVisible(false);

openPicture.addWindowListener(new WindowAdapter()

{

public void windowClosing(WindowEvent e)

{ openPicture.setVisible(false); }

});

savePicture.addWindowListener(new WindowAdapter()

{

public void windowClosing(WindowEvent e)

{ savePicture.setVisible(false); }

});

addWindowListener(new WindowAdapter()

{

public void windowClosing(WindowEvent e)

{ System.exit(0);}

});

}

public void paint(Graphics g)

{

Graphics2D g2d = (Graphics2D)g;

Point p1,p2;

n = paintInfo.size();

if(toolFlag==2)

g.clearRect(0,0,getSize().width,getSize().height);//清除

for(int i=0; in ;i++){

p1 = (Point)paintInfo.elementAt(i);

p2 = (Point)paintInfo.elementAt(i+1);

size = new BasicStroke(p1.boarder,BasicStroke.CAP_BUTT,BasicStroke.JOIN_BEVEL);

g2d.setColor(p1.col);

g2d.setStroke(size);

if(p1.tool==p2.tool)

{

switch(p1.tool)

{

case 0://画笔

Line2D line1 = new Line2D.Double(p1.x, p1.y, p2.x, p2.y);

g2d.draw(line1);

break;

case 1://橡皮

g.clearRect(p1.x, p1.y, p1.boarder, p1.boarder);

break;

case 3://画直线

Line2D line2 = new Line2D.Double(p1.x, p1.y, p2.x, p2.y);

g2d.draw(line2);

break;

case 4://画圆

Ellipse2D ellipse = new Ellipse2D.Double(p1.x, p1.y, Math.abs(p2.x-p1.x) , Math.abs(p2.y-p1.y));

g2d.draw(ellipse);

break;

case 5://画矩形

Rectangle2D rect = new Rectangle2D.Double(p1.x, p1.y, Math.abs(p2.x-p1.x) , Math.abs(p2.y-p1.y));

g2d.draw(rect);

break;

case 6://截断，跳过

i=i+1;

break;

default :

}//end switch

}//end if

}//end for

}

public void itemStateChanged(ItemEvent e)

{

if(e.getSource()==ColChoice)//预选颜色

{

String name = ColChoice.getSelectedItem();

if(name=="black")

{c = new Color(0,0,0); }

else if(name=="red")

{c = new Color(255,0,0);}

else if(name=="green")

{c = new Color(0,255,0);}

else if(name=="blue")

{c = new Color(0,0,255);}

}

else if(e.getSource()==SizeChoice)//画笔大小

{

String selected = SizeChoice.getSelectedItem();

if(selected=="1")

{

con = 1;