Java实现简单的绘图软件.doc

项目效果图：

项目源代码：
import java.awt.*;
import java.awt.event.*;
import java.awt.geom.Ellipse2D;
import java.awt.geom.Line2D;
import java.awt.geom.Rectangle2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;

import javax.imageio.ImageIO;
import javax.swing.*;
import javax.swing.filechooser.FileNameExtensionFilter;

/* author: 蒋冰 */
public class ImageDraw {
private int typeFlag = 1;
private int endFlag = 1;
private int strokeTemp = 1;
private Color color = Color.black;
private BasicStroke stroke = new BasicStroke();
private float pre_x = 0;
private float pre_y = 0;
private float start_x = 0;
private float start_y = 0;
private float start_X = 0;
private float start_Y = 0;
private float end_x = 0;
private float end_y = 0;
private float width = 0;
private float height = 0;
private final int AREA_WIDTH = 700;
private final int AREA_HEIGHT = 400;
private Line2D.Float line;
private Rectangle2D.Float rect;
private Ellipse2D.Float ellipse;
private File imageFile;
BufferedImage image = new BufferedImage(AREA_WIDTH , AREA_HEIGHT , BufferedImage.TYPE_INT_RGB);
Graphics2D g2 = (Graphics2D) image.getGraphics();
private JFrame frame = new JFrame("简单手绘程序");
private DrawPanel drawArea = new DrawPanel();
JButton buttonShowColor = new JButton("");

public void init(){
g2.fillRect(0 , 0 ,AREA_WIDTH , AREA_HEIGHT);
g2.setColor(Color.black);
drawArea.setPreferredSize(new Dimension(AREA_WIDTH , AREA_HEIGHT));
drawArea.addMouseMotionListener(new MouseMotionAdapter()
{
public void mouseDragged(MouseEvent e)
{
do_mouseDragged(e);
}

});

drawArea.addMouseListener(new MouseAdapter()
{
public void mousePressed(MouseEvent e1){
do_mousePressed(e1);

}
public void mouseReleased(MouseEvent e)
{
g2.setColor(color);
g2.setStroke(stroke);
endFlag = typeFlag;
drawArea.repaint();
}
public void mouseEntered(MouseEvent e){
frame.setCursor(new Cursor(Cursor.CROSSHAIR_CURSOR));
}
public void mouseExited(MouseEvent e){
frame.setCursor(null);
}
});

frame.add(drawArea);

JMenuBar mb = new JMenuBar();
JMenu menuFile = new JMenu("文件");

JMenuItem menuItemSave = new JMenuItem("保存");
menuItemSave.addActionListener(new ActionListener(){

public void actionPerformed(ActionEvent arg0) {
do_save_actionPerformed(arg0);
}

});

JMenuItem menuItemOpen = new JMenuItem("打开");
menuItemOpen.addActionListener(new ActionListener(){

public void actionPerformed(ActionEvent arg0) {
try {
do_open_actionPerformed(arg0);
} catch (IOException e) {
// TODO 自动生成的 catch 块
e.printStackTrace();
}
}

});

JMenuItem menuItemExit = new JMenuItem("退出");
menuItemExit.addActionListener(new ActionListener(){

public void actionPerformed(ActionEvent arg0) {
System.exit(0);
}

});

menuFile.add(menuItemSave);
menuFile.add(menuItemOpen);
menuFile.add(menuItemExit);
mb.add(menuFile);

JPanel buttonPanel = new JPanel();
FlowLayout layout = new FlowLayout(FlowLayout.CENTER, 20, 20);
buttonPanel.setLayout(layout);
buttonPanel.setBackground(Color.gray);

JButton buttonDraw = new JButton("绘图");
buttonDraw.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0) {
typeFlag = 1;
}
});
buttonPanel.add(buttonDraw);

JButton buttonLine = new JButton("直线");
buttonLine.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0) {
typeFlag = 2;
}
});
buttonPanel.add(buttonLine);

JButton buttonRect = new JButton("矩形");
buttonRect.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0) {
typeFlag = 3;
}
});
buttonPanel.add(buttonRect);

JButton buttonEllipse = new JButton("椭圆");
buttonEllipse.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0) {
typeFlag = 4;
}
});
buttonPanel.add(buttonEllipse);

JButton buttonDrop = new JButton("清除");
buttonDrop.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0) {
typeFlag = 5;
g2.setColor(Color.white);
g2.fillRect(0 , 0 ,AREA_WIDTH , AREA_HEIGHT);
drawArea.repaint();

}
});
buttonPanel.add(buttonDrop);

JButton buttonColorChoose = new JButton("选择颜色");
buttonColorChoose.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent arg0) {
do_buttonColorChoose_actionPerformed(arg0);
}
});
buttonPanel.add(buttonColorChoose);

buttonShowColor = new JButton("");
buttonPanel.add(buttonShowColor);

JLabel label = new JLabel("边框：");
buttonPanel.add(label);

JComboBox combox = new JComboBox();
for(int i=1; i<=36; i++){
combox.addItem(i);
}
combox.addItemListener(new ItemListener() {
public void itemStateChanged(ItemEvent e) {
strokeTemp = Integer.parseInt(e.getItem().toString()) ;
stroke = new BasicStroke(strokeTemp);
}
});
buttonPanel.add(combox);

frame.add(buttonPanel,BorderLayout.SOUTH);
frame.add(mb,BorderLayout.NORTH);

frame.setBackground(Color.gray);
frame.pack();
frame.setVisible(true);
}

public static void main(String[] args)
{
new ImageDraw().init();
}

class DrawPanel extends JPanel
{
public void paint(Graphics g)
{
Graphics2D g2 = (Graphics2D) g;
g2.clearRect(0, 0, AREA_WIDTH, AREA_HEIGHT);
g2.setColor(color);
g2.setStroke(stroke);
g2.drawImage(image , 0 , 0 , null);
if(typeFlag == 2){
line = new Line2D.Float(start_x, start_y, end_x, end_y);
g2.draw(line);
}
if(typeFlag == 3){
rect = new Rectangle2D.Float(start_X, start_Y, width, height);
g2.draw(rect);
}
if(typeFlag == 4){
ellipse = new Ellipse2D.Float(start_X, start_Y, width, height);
g2.draw(ellipse);
}
if(typeFlag == 5){
g2.setColor(Color.white);
g2.fillRect(0 , 0 ,AREA_WIDTH , AREA_HEIGHT);
}
}
}

private void do_save_actionPerformed(ActionEvent arg0) {
// TODO 自动生成的方法存根
JFileChooser chooser = new JFileChooser();
chooser.setSelectedFile(new File(imageFile.getName()));
int option = chooser.showSaveDialog(null);
if(option == JFileChooser.APPROVE_OPTION){
File file = chooser.getSelectedFile();
try {
ImageIO.write(image, "jpg", file);
} catch (IOException e) {
// TODO 自动生成的 catch 块
e.printStackTrace();
}
}
}

private void do_open_actionPerformed(ActionEvent arg0) throws IOException {
// TODO 自动生成的方法存根
JFileChooser chooser = new JFileChooser();
chooser.setFileFilter(new FileNameExtensionFilter("图片文件","jpg","jpeg","jif"));
chooser.setFileSelectionMode(JFileChooser.FILES_ONLY);
int option = chooser.showOpenDialog(null);
if(option == JFileChooser.APPROVE_OPTION){
imageFile = chooser.getSelectedFile();
Image sourceImage = ImageIO.read(imageFile);
g2.drawImage(sourceImage, 0, 0, sourceImage.getWidth(null), sourceImage.getHeight(null), null);
drawArea.repaint();
}
}

private void do_buttonColorChoose_actionPerformed(ActionEvent arg0) {
// TODO 自动生成的方法存根
JColorChooser chooser = new JColorChooser();
color = chooser.showDialog(null, "请选取颜色", Color.black);
buttonShowColor.setBackground(color);
}

private void do_mouseDragged(MouseEvent e) {

end_x = e.getX();
end_y = e.getY();

width = Math.abs( end_x - start_x );
height = Math.abs( end_y - start_y );

if(end_x <= start_x && end_y <= start_y){
start_X = start_x - width;
start_Y = start_y - height;
}

if(end_x > start_x && end_y < start_y){
start_Y = start_y - height;
start_X = start_x;
}

if(end_x <= start_x && end_y >= start_y){
start_Y = start_y;
start_X = start_x - width;
}

if(end_x >= start_x && end_y >=start_y){
start_Y = start_y;
start_X = start_x;
}
if(typeFlag == 1){
if (pre_x > 0 && pre_y > 0)
{
line = new Line2D.Float(pre_x, pre_y, end_x, end_y);
g2.setColor(color);
g2.setStroke(stroke);
g2.draw(line);
}
pre_x = e.getX();
pre_y = e.getY();
drawArea.repaint();
}else{
drawArea.repaint();
}
}

private void do_mousePressed(MouseEvent e1) {
// TODO 自动生成的方法存根
width = 0;
height = 0;

start_x = end_x = pre_x = e1.getX();
start_y = end_y = pre_y = e1.getY();

if(endFlag == 2){
g2.draw(line);
}
if(endFlag == 3){
g2.draw(rect);
}
if(endFlag == 4)
{
g2.draw(ellipse);
}
drawArea.repaint();
}
}