Java：使用文件选择器保存绘图板 (JComponent) 的图像。
Java: Save Image Of DrawingBoard(JComponent) Using A File Chooser.
该程序允许绘画，然后当您单击“文件”>“导出”时，绘图板的内容将导出为 JPeg 格式并保存到桌面。
但是保存时，即使声明它必须是白色，图像也会出现并且背景是黑色（问题）。
我还想让程序询问用户图片保存位置然后保存图片
你能解决这个问题吗？并帮助我添加 FileChooser
.不知道放哪了
这是我的代码：请帮忙。
import javax.swing.*;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyListener;
import java.awt.event.*;
import java.awt.*;
import java.awt.geom.*;
import java.text.DecimalFormat;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;
import java.io.File;
import javax.swing.ButtonGroup;
import javax.swing.JCheckBoxMenuItem;
import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JRadioButtonMenuItem;
import java.util.*;
import javax.imageio.ImageIO;
import javax.swing.event.MenuListener;
import java.awt.image.BufferedImage;
@SuppressWarnings("serial")
public class Lesson49_1 extends JFrame
{
JMenuBar menubar;
JMenu File, Exit;
JMenuItem New,Open;
JComponent DrawingBoard;
JButton brushBut, lineBut, ellipseBut, rectBut, strokeBut, fillBut;
// Slider used to change the transparency
JSlider transSlider;
JLabel transLabel;
// Makes sure the float for transparency only shows 2 digits
DecimalFormat dec = new DecimalFormat("#.##");
// Contains all of the rules for drawing
Graphics2D graphSettings;
// Homework use graphSettings.setStroke(new BasicStroke(5F));
// To change the stroke dynamically with a component
// Going to be used to monitor what shape to draw next
int currentAction = 1;
// Transparency of the shape
float transparentVal = 1.0f;
// Default stroke and fill colors
Color strokeColor=Color.RED, fillColor=Color.WHITE;
public static void main(String [] args)
{
new Lesson49_1();
}
public Lesson49_1()
{
// Define the defaults for the JFrame
this.setSize(800, 600);
this.setTitle("Java Paint");
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setJMenuBar(menubar);
JMenuBar menuBar = new JMenuBar();
// Add the menubar to the frame
setJMenuBar(menuBar);
// Define and add two drop down menu to the menubar
JMenu fileMenu = new JMenu("File");
JMenu editMenu = new JMenu("Edit");
JMenu dbMenu = new JMenu("Database");
JMenu ToolsMenu = new JMenu("Tools");
JMenu HelpMenu = new JMenu("Help");
menuBar.add(fileMenu);
menuBar.add(editMenu);
menuBar.add(dbMenu);
menuBar.add(ToolsMenu);
menuBar.add(HelpMenu);
// Create and add simple menu item to one of the drop down menu
JMenuItem newAction = new JMenuItem("New Project");
JMenuItem openAction = new JMenuItem("Open File");
JMenuItem exitAction = new JMenuItem("Quit");
JMenuItem cutAction = new JMenuItem("Cut");
JMenuItem copyAction = new JMenuItem("Copy");
JMenuItem pasteAction = new JMenuItem("Paste");
JMenuItem UndoAction = new JMenuItem("Undo");
JMenuItem RedoAction = new JMenuItem("Redo");
JMenuItem clearAction = new JMenuItem("Clear");
JMenuItem saveAction = new JMenuItem("Save");
JMenuItem exportAction = new JMenuItem("Export");
JMenuItem printAction = new JMenuItem("Print");
JMenuItem ConvertAction = new JMenuItem("Convert To Tables");
JMenuItem ColorAction = new JMenuItem("Color Picker");
JMenuItem ZoomAction = new JMenuItem("Zoom");
JMenuItem EntityAction = new JMenuItem("Entity & Attributes");
JMenuItem RelationshipAction = new JMenuItem("Relationship Attributes");
JMenuItem HelpAction = new JMenuItem("Help");
JMenuItem AboutAction = new JMenuItem("About");
fileMenu.add(newAction);
fileMenu.addSeparator();
fileMenu.add(openAction);
fileMenu.addSeparator();
fileMenu.add(saveAction);
fileMenu.addSeparator();
fileMenu.add(exportAction);
fileMenu.addSeparator();
fileMenu.add(printAction);
fileMenu.addSeparator();
fileMenu.add(exitAction);
editMenu.add(UndoAction);
editMenu.addSeparator();
editMenu.add(RedoAction);
editMenu.addSeparator();
editMenu.add(cutAction);
editMenu.addSeparator();
editMenu.add(copyAction);
editMenu.addSeparator();
editMenu.add(pasteAction);
editMenu.addSeparator();
editMenu.add(clearAction);
dbMenu.add(ConvertAction);
ToolsMenu.add(ColorAction);
ToolsMenu.addSeparator();
ToolsMenu.add(ZoomAction);
ToolsMenu.addSeparator();
ToolsMenu.add(EntityAction);
ToolsMenu.addSeparator();
ToolsMenu.add(RelationshipAction);
HelpMenu.add(HelpAction);
HelpMenu.addSeparator();
HelpMenu.add(AboutAction);
newAction.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
new Lesson49_1().setVisible(true);
}
});
JPanel buttonPanel = new JPanel();
// Swing box that will hold all the buttons
Box theBox = Box.createVerticalBox();
// Make all the buttons in makeMeButtons by passing the
// button icon.
brushBut = makeMeButtons("./src/brush.png", 1);
lineBut = makeMeButtons("./src/line.png", 2);
ellipseBut = makeMeButtons("./src/ellipse.png", 3);
rectBut = makeMeButtons("./src/rectangle.png", 4);
// Make all the buttons in makeMeColorButton by passing the
// button icon and true for stroke color or false for fill
strokeBut = makeMeColorButton("./src/stroke.png", 5, true);
fillBut = makeMeColorButton("./src/fill.png", 6, false);
// Add the buttons to the box
theBox.add(brushBut);
theBox.add(lineBut);
theBox.add(ellipseBut);
theBox.add(rectBut);
theBox.add(strokeBut);
theBox.add(fillBut);
// Add the transparent label and slider
transLabel = new JLabel("Transparent: 1");
// Min value, Max value and starting value for slider
transSlider = new JSlider(1, 99, 99);
// Create an instance of ListenForEvents to handle events
ListenForSlider lForSlider = new ListenForSlider();
// Tell Java that you want to be alerted when an event
// occurs on the slider
transSlider.addChangeListener(lForSlider);
theBox.add(transLabel);
theBox.add(transSlider);
buttonPanel.add(theBox);
this.add(buttonPanel, BorderLayout.WEST);
// Make the drawing area take up the rest of the frame
// this.add(new DrawingBoard(), BorderLayout.CENTER);
DrawingBoard drawPanel = new DrawingBoard();
this.add(drawPanel,BorderLayout.CENTER );
this.getContentPane().setBackground(Color.WHITE);
exportAction.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
BufferedImage image = new BufferedImage(drawPanel.getWidth(), drawPanel.getHeight(),
BufferedImage.TYPE_INT_RGB);
Graphics2D g = image.createGraphics();
drawPanel.paint(g);
try{
ImageIO.write(image,"png", new File("C:\Users\Wenda\Desktop\Image.png"));
JOptionPane.showMessageDialog(null,"Image Saved to desktop");
}
catch(Exception ex){
ex.printStackTrace();
}
}
});
// Show the frame
this.setVisible(true);
}
// Spits out buttons based on the image supplied
// actionNum represents each shape to be drawn
public JButton makeMeButtons(String iconFile, final int actionNum){
JButton theBut = new JButton();
Icon butIcon = new ImageIcon(iconFile);
theBut.setIcon(butIcon);
// Make the proper actionPerformed method execute when the
// specific button is pressed
theBut.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
currentAction = actionNum;
}
});
return theBut;
}
// Spits out buttons based on the image supplied and
// whether a stroke or fill is to be defined
public JButton makeMeColorButton(String iconFile, final int actionNum, final boolean stroke){
JButton theBut = new JButton();
Icon butIcon = new ImageIcon(iconFile);
theBut.setIcon(butIcon);
theBut.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if(stroke){
// JColorChooser is a popup that lets you pick a color
strokeColor = JColorChooser.showDialog(null, "Pick a Stroke", Color.BLACK);
} else {
fillColor = JColorChooser.showDialog(null, "Pick a Fill", Color.WHITE);
}
}
});
return theBut;
}
public class DrawingBoard extends JComponent
{
// ArrayLists that contain each shape drawn along with
// that shapes stroke and fill
ArrayList<Shape> shapes = new ArrayList<Shape>();
ArrayList<Color> shapeFill = new ArrayList<Color>();
ArrayList<Color> shapeStroke = new ArrayList<Color>();
ArrayList<Float> transPercent = new ArrayList<Float>();
Point drawStart, drawEnd;
// Monitors events on the drawing area of the frame
public DrawingBoard()
{
this.addMouseListener(new MouseAdapter()
{
public void mousePressed(MouseEvent e)
{
if(currentAction != 1){
// When the mouse is pressed get x & y position
drawStart = new Point(e.getX(), e.getY());
drawEnd = drawStart;
repaint();
}
}
public void mouseReleased(MouseEvent e)
{
if(currentAction != 1){
// Create a shape using the starting x & y
// and finishing x & y positions
Shape aShape = null;
if (currentAction == 2){
aShape = drawLine(drawStart.x, drawStart.y,
e.getX(), e.getY());
} else
if (currentAction == 3){
aShape = drawEllipse(drawStart.x, drawStart.y,
e.getX(), e.getY());
} else
if (currentAction == 4) {
// Create a new rectangle using x & y coordinates
aShape = drawRectangle(drawStart.x, drawStart.y,
e.getX(), e.getY());
}
// Add shapes, fills and colors to there ArrayLists
shapes.add(aShape);
shapeFill.add(fillColor);
shapeStroke.add(strokeColor);
// Add transparency value to ArrayList
transPercent.add(transparentVal);
drawStart = null;
drawEnd = null;
// repaint the drawing area
repaint();
}
}
} );
this.addMouseMotionListener(new MouseMotionAdapter()
{
public void mouseDragged(MouseEvent e)
{
// If this is a brush have shapes go on the screen quickly
if(currentAction == 1){
int x = e.getX();
int y = e.getY();
Shape aShape = null;
// Make stroke and fill equal to eliminate the fact that this is an ellipse
strokeColor = fillColor;
aShape = drawBrush(x,y,5,5);
shapes.add(aShape);
shapeFill.add(fillColor);
shapeStroke.add(strokeColor);
// Add the transparency value
transPercent.add(transparentVal);
}
// Get the final x & y position after the mouse is dragged
drawEnd = new Point(e.getX(), e.getY());
repaint();
}
} );
}
public void paint(Graphics g)
{
// Class used to define the shapes to be drawn
graphSettings = (Graphics2D)g;
// Antialiasing cleans up the jagged lines and defines rendering rules
graphSettings.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
// Defines the line width of the stroke
graphSettings.setStroke(new BasicStroke(4));
// Iterators created to cycle through strokes and fills
Iterator<Color> strokeCounter = shapeStroke.iterator();
Iterator<Color> fillCounter = shapeFill.iterator();
// Iterator for transparency
Iterator<Float> transCounter = transPercent.iterator();
for (Shape s : shapes)
{
// Sets the shapes transparency value
graphSettings.setComposite(AlphaComposite.getInstance(
AlphaComposite.SRC_OVER, transCounter.next()));
// Grabs the next stroke from the color arraylist
graphSettings.setPaint(strokeCounter.next());
graphSettings.draw(s);
// Grabs the next fill from the color arraylist
graphSettings.setPaint(fillCounter.next());
graphSettings.fill(s);
}
// Guide shape used for drawing
if (drawStart != null && drawEnd != null)
{
// Makes the guide shape transparent
graphSettings.setComposite(AlphaComposite.getInstance(
AlphaComposite.SRC_OVER, 0.40f));
// Make guide shape gray for professional look
graphSettings.setPaint(Color.LIGHT_GRAY);
Shape aShape = null;
if (currentAction == 2){
aShape = drawLine(drawStart.x, drawStart.y,
drawEnd.x, drawEnd.y);
} else
if (currentAction == 3){
aShape = drawEllipse(drawStart.x, drawStart.y,
drawEnd.x, drawEnd.y);
} else
if (currentAction == 4) {
// Create a new rectangle using x & y coordinates
aShape = drawRectangle(drawStart.x, drawStart.y,
drawEnd.x, drawEnd.y);
}
graphSettings.draw(aShape);
}
}
private Rectangle2D.Float drawRectangle(
int x1, int y1, int x2, int y2)
{
// Get the top left hand corner for the shape
// Math.min returns the points closest to 0
int x = Math.min(x1, x2);
int y = Math.min(y1, y2);
// Gets the difference between the coordinates and
int width = Math.abs(x1 - x2);
int height = Math.abs(y1 - y2);
return new Rectangle2D.Float(
x, y, width, height);
}
// The other shapes will work similarly
// More on this in the next tutorial
private Ellipse2D.Float drawEllipse(
int x1, int y1, int x2, int y2)
{
int x = Math.min(x1, x2);
int y = Math.min(y1, y2);
int width = Math.abs(x1 - x2);
int height = Math.abs(y1 - y2);
return new Ellipse2D.Float(
x, y, width, height);
}
private Line2D.Float drawLine(
int x1, int y1, int x2, int y2)
{
return new Line2D.Float(
x1, y1, x2, y2);
}
private Ellipse2D.Float drawBrush(
int x1, int y1, int brushStrokeWidth, int brushStrokeHeight)
{
return new Ellipse2D.Float(
x1, y1, brushStrokeWidth, brushStrokeHeight);
}
}
// Implements ActionListener so it can react to events on components
private class ListenForSlider implements ChangeListener{
// Called when the spinner is changed
public void stateChanged(ChangeEvent e) {
// Check if the source of the event was the button
if(e.getSource() == transSlider){
// Change the value for the label next to the spinner
// Use decimal format to make sure only 2 decimals are ever displayed
transLabel.setText("Transparent: " + dec.format(transSlider.getValue() * .01) );
// Set the value for transparency for every shape drawn after
transparentVal = (float) (transSlider.getValue() * .01);
}
}
}
}
你有 1 个编译错误我必须修复。你有几个我没有的输入 png 图片。
我将 JFileChooser 添加到您的导出操作侦听器。我还格式化了你的 Java 应用程序。
您应该在 JPanel 上绘画并覆盖 paintComponent 方法。我通过创建 ARGB BufferedImage 修复了黑色背景。
这是代码。
package com.ggl.fse;
import java.awt.AlphaComposite;
import java.awt.BasicStroke;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.RenderingHints;
import java.awt.Shape;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionAdapter;
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.text.DecimalFormat;
import java.util.ArrayList;
import java.util.Iterator;
import javax.imageio.ImageIO;
import javax.swing.Box;
import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JColorChooser;
import javax.swing.JComponent;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JSlider;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
import javax.swing.filechooser.FileNameExtensionFilter;
public class Lesson49_1 extends JFrame {
private static final long serialVersionUID = -140274271716086522L;
JMenuBar menubar;
JMenu File, Exit;
JMenuItem New, Open;
JComponent DrawingBoard;
JButton brushBut, lineBut, ellipseBut, rectBut, strokeBut, fillBut;
// Slider used to change the transparency
JSlider transSlider;
JLabel transLabel;
// Makes sure the float for transparency only shows 2 digits
DecimalFormat dec = new DecimalFormat("#.##");
// Contains all of the rules for drawing
Graphics2D graphSettings;
// Homework use graphSettings.setStroke(new BasicStroke(5F));
// To change the stroke dynamically with a component
// Going to be used to monitor what shape to draw next
int currentAction = 1;
// Transparency of the shape
float transparentVal = 1.0f;
// Default stroke and fill colors
Color strokeColor = Color.RED, fillColor = Color.WHITE;
public static void main(String[] args) {
new Lesson49_1();
}
public Lesson49_1() {
// Define the defaults for the JFrame
this.setSize(800, 600);
this.setTitle("Java Paint");
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setJMenuBar(menubar);
JMenuBar menuBar = new JMenuBar();
// Add the menubar to the frame
setJMenuBar(menuBar);
// Define and add two drop down menu to the menubar
JMenu fileMenu = new JMenu("File");
JMenu editMenu = new JMenu("Edit");
JMenu dbMenu = new JMenu("Database");
JMenu ToolsMenu = new JMenu("Tools");
JMenu HelpMenu = new JMenu("Help");
menuBar.add(fileMenu);
menuBar.add(editMenu);
menuBar.add(dbMenu);
menuBar.add(ToolsMenu);
menuBar.add(HelpMenu);
// Create and add simple menu item to one of the drop down menu
JMenuItem newAction = new JMenuItem("New Project");
JMenuItem openAction = new JMenuItem("Open File");
JMenuItem exitAction = new JMenuItem("Quit");
JMenuItem cutAction = new JMenuItem("Cut");
JMenuItem copyAction = new JMenuItem("Copy");
JMenuItem pasteAction = new JMenuItem("Paste");
JMenuItem UndoAction = new JMenuItem("Undo");
JMenuItem RedoAction = new JMenuItem("Redo");
JMenuItem clearAction = new JMenuItem("Clear");
JMenuItem saveAction = new JMenuItem("Save");
JMenuItem exportAction = new JMenuItem("Export");
JMenuItem printAction = new JMenuItem("Print");
JMenuItem ConvertAction = new JMenuItem("Convert To Tables");
JMenuItem ColorAction = new JMenuItem("Color Picker");
JMenuItem ZoomAction = new JMenuItem("Zoom");
JMenuItem EntityAction = new JMenuItem("Entity & Attributes");
JMenuItem RelationshipAction = new JMenuItem("Relationship Attributes");
JMenuItem HelpAction = new JMenuItem("Help");
JMenuItem AboutAction = new JMenuItem("About");
fileMenu.add(newAction);
fileMenu.addSeparator();
fileMenu.add(openAction);
fileMenu.addSeparator();
fileMenu.add(saveAction);
fileMenu.addSeparator();
fileMenu.add(exportAction);
fileMenu.addSeparator();
fileMenu.add(printAction);
fileMenu.addSeparator();
fileMenu.add(exitAction);
editMenu.add(UndoAction);
editMenu.addSeparator();
editMenu.add(RedoAction);
editMenu.addSeparator();
editMenu.add(cutAction);
editMenu.addSeparator();
editMenu.add(copyAction);
editMenu.addSeparator();
editMenu.add(pasteAction);
editMenu.addSeparator();
editMenu.add(clearAction);
dbMenu.add(ConvertAction);
ToolsMenu.add(ColorAction);
ToolsMenu.addSeparator();
ToolsMenu.add(ZoomAction);
ToolsMenu.addSeparator();
ToolsMenu.add(EntityAction);
ToolsMenu.addSeparator();
ToolsMenu.add(RelationshipAction);
HelpMenu.add(HelpAction);
HelpMenu.addSeparator();
HelpMenu.add(AboutAction);
newAction.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
new Lesson49_1().setVisible(true);
}
});
JPanel buttonPanel = new JPanel();
// Swing box that will hold all the buttons
Box theBox = Box.createVerticalBox();
// Make all the buttons in makeMeButtons by passing the
// button icon.
brushBut = makeMeButtons("./src/brush.png", 1);
lineBut = makeMeButtons("./src/line.png", 2);
ellipseBut = makeMeButtons("./src/ellipse.png", 3);
rectBut = makeMeButtons("./src/rectangle.png", 4);
// Make all the buttons in makeMeColorButton by passing the
// button icon and true for stroke color or false for fill
strokeBut = makeMeColorButton("./src/stroke.png", 5, true);
fillBut = makeMeColorButton("./src/fill.png", 6, false);
// Add the buttons to the box
theBox.add(brushBut);
theBox.add(lineBut);
theBox.add(ellipseBut);
theBox.add(rectBut);
theBox.add(strokeBut);
theBox.add(fillBut);
// Add the transparent label and slider
transLabel = new JLabel("Transparent: 1");
// Min value, Max value and starting value for slider
transSlider = new JSlider(1, 99, 99);
// Create an instance of ListenForEvents to handle events
ListenForSlider lForSlider = new ListenForSlider();
// Tell Java that you want to be alerted when an event
// occurs on the slider
transSlider.addChangeListener(lForSlider);
theBox.add(transLabel);
theBox.add(transSlider);
buttonPanel.add(theBox);
this.add(buttonPanel, BorderLayout.WEST);
// Make the drawing area take up the rest of the frame
// this.add(new DrawingBoard(), BorderLayout.CENTER);
final DrawingBoard drawPanel = new DrawingBoard();
this.add(drawPanel, BorderLayout.CENTER);
this.getContentPane().setBackground(Color.WHITE);
exportAction.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
BufferedImage image = new BufferedImage(drawPanel.getWidth(),
drawPanel.getHeight(), BufferedImage.TYPE_INT_ARGB);
Graphics2D g = image.createGraphics();
drawPanel.paint(g);
g.dispose();
JFileChooser fileChooser = new JFileChooser();
File theDirectory = new File("C:/Users/Wenda/Desktop");
fileChooser.setCurrentDirectory(theDirectory);
FileNameExtensionFilter pngFilter = new FileNameExtensionFilter(
"PNG file (*.png)", "png");
fileChooser.addChoosableFileFilter(pngFilter);
fileChooser.setFileFilter(pngFilter);
int status = fileChooser.showSaveDialog(Lesson49_1.this);
if (status == JFileChooser.APPROVE_OPTION) {
try {
ImageIO.write(image, "png",
fileChooser.getSelectedFile());
JOptionPane.showMessageDialog(null, "Image saved to "
+ fileChooser.getSelectedFile().getName());
} catch (Exception ex) {
ex.printStackTrace();
}
}
}
});
// Show the frame
this.setVisible(true);
}
// Spits out buttons based on the image supplied
// actionNum represents each shape to be drawn
public JButton makeMeButtons(String iconFile, final int actionNum) {
JButton theBut = new JButton();
Icon butIcon = new ImageIcon(iconFile);
theBut.setIcon(butIcon);
// Make the proper actionPerformed method execute when the
// specific button is pressed
theBut.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
currentAction = actionNum;
}
});
return theBut;
}
// Spits out buttons based on the image supplied and
// whether a stroke or fill is to be defined
public JButton makeMeColorButton(String iconFile, final int actionNum,
final boolean stroke) {
JButton theBut = new JButton();
Icon butIcon = new ImageIcon(iconFile);
theBut.setIcon(butIcon);
theBut.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if (stroke) {
// JColorChooser is a popup that lets you pick a color
strokeColor = JColorChooser.showDialog(null,
"Pick a Stroke", Color.BLACK);
} else {
fillColor = JColorChooser.showDialog(null, "Pick a Fill",
Color.WHITE);
}
}
});
return theBut;
}
public class DrawingBoard extends JComponent {
private static final long serialVersionUID = -4431176095451940075L;
// ArrayLists that contain each shape drawn along with
// that shapes stroke and fill
ArrayList<Shape> shapes = new ArrayList<Shape>();
ArrayList<Color> shapeFill = new ArrayList<Color>();
ArrayList<Color> shapeStroke = new ArrayList<Color>();
ArrayList<Float> transPercent = new ArrayList<Float>();
Point drawStart, drawEnd;
// Monitors events on the drawing area of the frame
public DrawingBoard() {
this.addMouseListener(new MouseAdapter() {
public void mousePressed(MouseEvent e) {
if (currentAction != 1) {
// When the mouse is pressed get x & y position
drawStart = new Point(e.getX(), e.getY());
drawEnd = drawStart;
repaint();
}
}
public void mouseReleased(MouseEvent e) {
if (currentAction != 1) {
// Create a shape using the starting x & y
// and finishing x & y positions
Shape aShape = null;
if (currentAction == 2) {
aShape = drawLine(drawStart.x, drawStart.y,
e.getX(), e.getY());
} else
if (currentAction == 3) {
aShape = drawEllipse(drawStart.x, drawStart.y,
e.getX(), e.getY());
} else
if (currentAction == 4) {
// Create a new rectangle using x & y coordinates
aShape = drawRectangle(drawStart.x, drawStart.y,
e.getX(), e.getY());
}
// Add shapes, fills and colors to there ArrayLists
shapes.add(aShape);
shapeFill.add(fillColor);
shapeStroke.add(strokeColor);
// Add transparency value to ArrayList
transPercent.add(transparentVal);
drawStart = null;
drawEnd = null;
// repaint the drawing area
repaint();
}
}
});
this.addMouseMotionListener(new MouseMotionAdapter() {
public void mouseDragged(MouseEvent e) {
// If this is a brush have shapes go on the screen quickly
if (currentAction == 1) {
int x = e.getX();
int y = e.getY();
Shape aShape = null;
// Make stroke and fill equal to eliminate the fact that
// this is an ellipse
strokeColor = fillColor;
aShape = drawBrush(x, y, 5, 5);
shapes.add(aShape);
shapeFill.add(fillColor);
shapeStroke.add(strokeColor);
// Add the transparency value
transPercent.add(transparentVal);
}
// Get the final x & y position after the mouse is dragged
drawEnd = new Point(e.getX(), e.getY());
repaint();
}
});
}
public void paint(Graphics g) {
// Class used to define the shapes to be drawn
graphSettings = (Graphics2D) g;
// Antialiasing cleans up the jagged lines and defines rendering
// rules
graphSettings.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
// Defines the line width of the stroke
graphSettings.setStroke(new BasicStroke(4));
// Iterators created to cycle through strokes and fills
Iterator<Color> strokeCounter = shapeStroke.iterator();
Iterator<Color> fillCounter = shapeFill.iterator();
// Iterator for transparency
Iterator<Float> transCounter = transPercent.iterator();
for (Shape s : shapes) {
// Sets the shapes transparency value
graphSettings.setComposite(AlphaComposite.getInstance(
AlphaComposite.SRC_OVER, transCounter.next()));
// Grabs the next stroke from the color arraylist
graphSettings.setPaint(strokeCounter.next());
graphSettings.draw(s);
// Grabs the next fill from the color arraylist
graphSettings.setPaint(fillCounter.next());
graphSettings.fill(s);
}
// Guide shape used for drawing
if (drawStart != null && drawEnd != null) {
// Makes the guide shape transparent
graphSettings.setComposite(AlphaComposite.getInstance(
AlphaComposite.SRC_OVER, 0.40f));
// Make guide shape gray for professional look
graphSettings.setPaint(Color.LIGHT_GRAY);
Shape aShape = null;
if (currentAction == 2) {
aShape = drawLine(drawStart.x, drawStart.y, drawEnd.x,
drawEnd.y);
} else
if (currentAction == 3) {
aShape = drawEllipse(drawStart.x, drawStart.y, drawEnd.x,
drawEnd.y);
} else
if (currentAction == 4) {
// Create a new rectangle using x & y coordinates
aShape = drawRectangle(drawStart.x, drawStart.y, drawEnd.x,
drawEnd.y);
}
graphSettings.draw(aShape);
}
}
private Rectangle2D.Float drawRectangle(int x1, int y1, int x2, int y2) {
// Get the top left hand corner for the shape
// Math.min returns the points closest to 0
int x = Math.min(x1, x2);
int y = Math.min(y1, y2);
// Gets the difference between the coordinates and
int width = Math.abs(x1 - x2);
int height = Math.abs(y1 - y2);
return new Rectangle2D.Float(x, y, width, height);
}
// The other shapes will work similarly
// More on this in the next tutorial
private Ellipse2D.Float drawEllipse(int x1, int y1, int x2, int y2) {
int x = Math.min(x1, x2);
int y = Math.min(y1, y2);
int width = Math.abs(x1 - x2);
int height = Math.abs(y1 - y2);
return new Ellipse2D.Float(x, y, width, height);
}
private Line2D.Float drawLine(int x1, int y1, int x2, int y2) {
return new Line2D.Float(x1, y1, x2, y2);
}
private Ellipse2D.Float drawBrush(int x1, int y1, int brushStrokeWidth,
int brushStrokeHeight) {
return new Ellipse2D.Float(x1, y1, brushStrokeWidth,
brushStrokeHeight);
}
}
// Implements ActionListener so it can react to events on components
private class ListenForSlider implements ChangeListener {
// Called when the spinner is changed
public void stateChanged(ChangeEvent e) {
// Check if the source of the event was the button
if (e.getSource() == transSlider) {
// Change the value for the label next to the spinner
// Use decimal format to make sure only 2 decimals are ever
// displayed
transLabel.setText("Transparent: "
+ dec.format(transSlider.getValue() * .01));
// Set the value for transparency for every shape drawn after
transparentVal = (float) (transSlider.getValue() * .01);
}
}
}
}
该程序允许绘画，然后当您单击“文件”>“导出”时，绘图板的内容将导出为 JPeg 格式并保存到桌面。 但是保存时，即使声明它必须是白色，图像也会出现并且背景是黑色（问题）。
我还想让程序询问用户图片保存位置然后保存图片
你能解决这个问题吗？并帮助我添加 FileChooser .不知道放哪了
这是我的代码：请帮忙。
import javax.swing.*;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyListener;
import java.awt.event.*;
import java.awt.*;
import java.awt.geom.*;
import java.text.DecimalFormat;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;
import java.io.File;
import javax.swing.ButtonGroup;
import javax.swing.JCheckBoxMenuItem;
import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JRadioButtonMenuItem;
import java.util.*;
import javax.imageio.ImageIO;
import javax.swing.event.MenuListener;
import java.awt.image.BufferedImage;
@SuppressWarnings("serial")
public class Lesson49_1 extends JFrame
{
JMenuBar menubar;
JMenu File, Exit;
JMenuItem New,Open;
JComponent DrawingBoard;
JButton brushBut, lineBut, ellipseBut, rectBut, strokeBut, fillBut;
// Slider used to change the transparency
JSlider transSlider;
JLabel transLabel;
// Makes sure the float for transparency only shows 2 digits
DecimalFormat dec = new DecimalFormat("#.##");
// Contains all of the rules for drawing
Graphics2D graphSettings;
// Homework use graphSettings.setStroke(new BasicStroke(5F));
// To change the stroke dynamically with a component
// Going to be used to monitor what shape to draw next
int currentAction = 1;
// Transparency of the shape
float transparentVal = 1.0f;
// Default stroke and fill colors
Color strokeColor=Color.RED, fillColor=Color.WHITE;
public static void main(String [] args)
{
new Lesson49_1();
}
public Lesson49_1()
{
// Define the defaults for the JFrame
this.setSize(800, 600);
this.setTitle("Java Paint");
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setJMenuBar(menubar);
JMenuBar menuBar = new JMenuBar();
// Add the menubar to the frame
setJMenuBar(menuBar);
// Define and add two drop down menu to the menubar
JMenu fileMenu = new JMenu("File");
JMenu editMenu = new JMenu("Edit");
JMenu dbMenu = new JMenu("Database");
JMenu ToolsMenu = new JMenu("Tools");
JMenu HelpMenu = new JMenu("Help");
menuBar.add(fileMenu);
menuBar.add(editMenu);
menuBar.add(dbMenu);
menuBar.add(ToolsMenu);
menuBar.add(HelpMenu);
// Create and add simple menu item to one of the drop down menu
JMenuItem newAction = new JMenuItem("New Project");
JMenuItem openAction = new JMenuItem("Open File");
JMenuItem exitAction = new JMenuItem("Quit");
JMenuItem cutAction = new JMenuItem("Cut");
JMenuItem copyAction = new JMenuItem("Copy");
JMenuItem pasteAction = new JMenuItem("Paste");
JMenuItem UndoAction = new JMenuItem("Undo");
JMenuItem RedoAction = new JMenuItem("Redo");
JMenuItem clearAction = new JMenuItem("Clear");
JMenuItem saveAction = new JMenuItem("Save");
JMenuItem exportAction = new JMenuItem("Export");
JMenuItem printAction = new JMenuItem("Print");
JMenuItem ConvertAction = new JMenuItem("Convert To Tables");
JMenuItem ColorAction = new JMenuItem("Color Picker");
JMenuItem ZoomAction = new JMenuItem("Zoom");
JMenuItem EntityAction = new JMenuItem("Entity & Attributes");
JMenuItem RelationshipAction = new JMenuItem("Relationship Attributes");
JMenuItem HelpAction = new JMenuItem("Help");
JMenuItem AboutAction = new JMenuItem("About");
fileMenu.add(newAction);
fileMenu.addSeparator();
fileMenu.add(openAction);
fileMenu.addSeparator();
fileMenu.add(saveAction);
fileMenu.addSeparator();
fileMenu.add(exportAction);
fileMenu.addSeparator();
fileMenu.add(printAction);
fileMenu.addSeparator();
fileMenu.add(exitAction);
editMenu.add(UndoAction);
editMenu.addSeparator();
editMenu.add(RedoAction);
editMenu.addSeparator();
editMenu.add(cutAction);
editMenu.addSeparator();
editMenu.add(copyAction);
editMenu.addSeparator();
editMenu.add(pasteAction);
editMenu.addSeparator();
editMenu.add(clearAction);
dbMenu.add(ConvertAction);
ToolsMenu.add(ColorAction);
ToolsMenu.addSeparator();
ToolsMenu.add(ZoomAction);
ToolsMenu.addSeparator();
ToolsMenu.add(EntityAction);
ToolsMenu.addSeparator();
ToolsMenu.add(RelationshipAction);
HelpMenu.add(HelpAction);
HelpMenu.addSeparator();
HelpMenu.add(AboutAction);
newAction.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
new Lesson49_1().setVisible(true);
}
});
JPanel buttonPanel = new JPanel();
// Swing box that will hold all the buttons
Box theBox = Box.createVerticalBox();
// Make all the buttons in makeMeButtons by passing the
// button icon.
brushBut = makeMeButtons("./src/brush.png", 1);
lineBut = makeMeButtons("./src/line.png", 2);
ellipseBut = makeMeButtons("./src/ellipse.png", 3);
rectBut = makeMeButtons("./src/rectangle.png", 4);
// Make all the buttons in makeMeColorButton by passing the
// button icon and true for stroke color or false for fill
strokeBut = makeMeColorButton("./src/stroke.png", 5, true);
fillBut = makeMeColorButton("./src/fill.png", 6, false);
// Add the buttons to the box
theBox.add(brushBut);
theBox.add(lineBut);
theBox.add(ellipseBut);
theBox.add(rectBut);
theBox.add(strokeBut);
theBox.add(fillBut);
// Add the transparent label and slider
transLabel = new JLabel("Transparent: 1");
// Min value, Max value and starting value for slider
transSlider = new JSlider(1, 99, 99);
// Create an instance of ListenForEvents to handle events
ListenForSlider lForSlider = new ListenForSlider();
// Tell Java that you want to be alerted when an event
// occurs on the slider
transSlider.addChangeListener(lForSlider);
theBox.add(transLabel);
theBox.add(transSlider);
buttonPanel.add(theBox);
this.add(buttonPanel, BorderLayout.WEST);
// Make the drawing area take up the rest of the frame
// this.add(new DrawingBoard(), BorderLayout.CENTER);
DrawingBoard drawPanel = new DrawingBoard();
this.add(drawPanel,BorderLayout.CENTER );
this.getContentPane().setBackground(Color.WHITE);
exportAction.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
BufferedImage image = new BufferedImage(drawPanel.getWidth(), drawPanel.getHeight(),
BufferedImage.TYPE_INT_RGB);
Graphics2D g = image.createGraphics();
drawPanel.paint(g);
try{
ImageIO.write(image,"png", new File("C:\Users\Wenda\Desktop\Image.png"));
JOptionPane.showMessageDialog(null,"Image Saved to desktop");
}
catch(Exception ex){
ex.printStackTrace();
}
}
});
// Show the frame
this.setVisible(true);
}
// Spits out buttons based on the image supplied
// actionNum represents each shape to be drawn
public JButton makeMeButtons(String iconFile, final int actionNum){
JButton theBut = new JButton();
Icon butIcon = new ImageIcon(iconFile);
theBut.setIcon(butIcon);
// Make the proper actionPerformed method execute when the
// specific button is pressed
theBut.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
currentAction = actionNum;
}
});
return theBut;
}
// Spits out buttons based on the image supplied and
// whether a stroke or fill is to be defined
public JButton makeMeColorButton(String iconFile, final int actionNum, final boolean stroke){
JButton theBut = new JButton();
Icon butIcon = new ImageIcon(iconFile);
theBut.setIcon(butIcon);
theBut.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if(stroke){
// JColorChooser is a popup that lets you pick a color
strokeColor = JColorChooser.showDialog(null, "Pick a Stroke", Color.BLACK);
} else {
fillColor = JColorChooser.showDialog(null, "Pick a Fill", Color.WHITE);
}
}
});
return theBut;
}
public class DrawingBoard extends JComponent
{
// ArrayLists that contain each shape drawn along with
// that shapes stroke and fill
ArrayList<Shape> shapes = new ArrayList<Shape>();
ArrayList<Color> shapeFill = new ArrayList<Color>();
ArrayList<Color> shapeStroke = new ArrayList<Color>();
ArrayList<Float> transPercent = new ArrayList<Float>();
Point drawStart, drawEnd;
// Monitors events on the drawing area of the frame
public DrawingBoard()
{
this.addMouseListener(new MouseAdapter()
{
public void mousePressed(MouseEvent e)
{
if(currentAction != 1){
// When the mouse is pressed get x & y position
drawStart = new Point(e.getX(), e.getY());
drawEnd = drawStart;
repaint();
}
}
public void mouseReleased(MouseEvent e)
{
if(currentAction != 1){
// Create a shape using the starting x & y
// and finishing x & y positions
Shape aShape = null;
if (currentAction == 2){
aShape = drawLine(drawStart.x, drawStart.y,
e.getX(), e.getY());
} else
if (currentAction == 3){
aShape = drawEllipse(drawStart.x, drawStart.y,
e.getX(), e.getY());
} else
if (currentAction == 4) {
// Create a new rectangle using x & y coordinates
aShape = drawRectangle(drawStart.x, drawStart.y,
e.getX(), e.getY());
}
// Add shapes, fills and colors to there ArrayLists
shapes.add(aShape);
shapeFill.add(fillColor);
shapeStroke.add(strokeColor);
// Add transparency value to ArrayList
transPercent.add(transparentVal);
drawStart = null;
drawEnd = null;
// repaint the drawing area
repaint();
}
}
} );
this.addMouseMotionListener(new MouseMotionAdapter()
{
public void mouseDragged(MouseEvent e)
{
// If this is a brush have shapes go on the screen quickly
if(currentAction == 1){
int x = e.getX();
int y = e.getY();
Shape aShape = null;
// Make stroke and fill equal to eliminate the fact that this is an ellipse
strokeColor = fillColor;
aShape = drawBrush(x,y,5,5);
shapes.add(aShape);
shapeFill.add(fillColor);
shapeStroke.add(strokeColor);
// Add the transparency value
transPercent.add(transparentVal);
}
// Get the final x & y position after the mouse is dragged
drawEnd = new Point(e.getX(), e.getY());
repaint();
}
} );
}
public void paint(Graphics g)
{
// Class used to define the shapes to be drawn
graphSettings = (Graphics2D)g;
// Antialiasing cleans up the jagged lines and defines rendering rules
graphSettings.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
// Defines the line width of the stroke
graphSettings.setStroke(new BasicStroke(4));
// Iterators created to cycle through strokes and fills
Iterator<Color> strokeCounter = shapeStroke.iterator();
Iterator<Color> fillCounter = shapeFill.iterator();
// Iterator for transparency
Iterator<Float> transCounter = transPercent.iterator();
for (Shape s : shapes)
{
// Sets the shapes transparency value
graphSettings.setComposite(AlphaComposite.getInstance(
AlphaComposite.SRC_OVER, transCounter.next()));
// Grabs the next stroke from the color arraylist
graphSettings.setPaint(strokeCounter.next());
graphSettings.draw(s);
// Grabs the next fill from the color arraylist
graphSettings.setPaint(fillCounter.next());
graphSettings.fill(s);
}
// Guide shape used for drawing
if (drawStart != null && drawEnd != null)
{
// Makes the guide shape transparent
graphSettings.setComposite(AlphaComposite.getInstance(
AlphaComposite.SRC_OVER, 0.40f));
// Make guide shape gray for professional look
graphSettings.setPaint(Color.LIGHT_GRAY);
Shape aShape = null;
if (currentAction == 2){
aShape = drawLine(drawStart.x, drawStart.y,
drawEnd.x, drawEnd.y);
} else
if (currentAction == 3){
aShape = drawEllipse(drawStart.x, drawStart.y,
drawEnd.x, drawEnd.y);
} else
if (currentAction == 4) {
// Create a new rectangle using x & y coordinates
aShape = drawRectangle(drawStart.x, drawStart.y,
drawEnd.x, drawEnd.y);
}
graphSettings.draw(aShape);
}
}
private Rectangle2D.Float drawRectangle(
int x1, int y1, int x2, int y2)
{
// Get the top left hand corner for the shape
// Math.min returns the points closest to 0
int x = Math.min(x1, x2);
int y = Math.min(y1, y2);
// Gets the difference between the coordinates and
int width = Math.abs(x1 - x2);
int height = Math.abs(y1 - y2);
return new Rectangle2D.Float(
x, y, width, height);
}
// The other shapes will work similarly
// More on this in the next tutorial
private Ellipse2D.Float drawEllipse(
int x1, int y1, int x2, int y2)
{
int x = Math.min(x1, x2);
int y = Math.min(y1, y2);
int width = Math.abs(x1 - x2);
int height = Math.abs(y1 - y2);
return new Ellipse2D.Float(
x, y, width, height);
}
private Line2D.Float drawLine(
int x1, int y1, int x2, int y2)
{
return new Line2D.Float(
x1, y1, x2, y2);
}
private Ellipse2D.Float drawBrush(
int x1, int y1, int brushStrokeWidth, int brushStrokeHeight)
{
return new Ellipse2D.Float(
x1, y1, brushStrokeWidth, brushStrokeHeight);
}
}
// Implements ActionListener so it can react to events on components
private class ListenForSlider implements ChangeListener{
// Called when the spinner is changed
public void stateChanged(ChangeEvent e) {
// Check if the source of the event was the button
if(e.getSource() == transSlider){
// Change the value for the label next to the spinner
// Use decimal format to make sure only 2 decimals are ever displayed
transLabel.setText("Transparent: " + dec.format(transSlider.getValue() * .01) );
// Set the value for transparency for every shape drawn after
transparentVal = (float) (transSlider.getValue() * .01);
}
}
}
}
你有 1 个编译错误我必须修复。你有几个我没有的输入 png 图片。
我将 JFileChooser 添加到您的导出操作侦听器。我还格式化了你的 Java 应用程序。
您应该在 JPanel 上绘画并覆盖 paintComponent 方法。我通过创建 ARGB BufferedImage 修复了黑色背景。
这是代码。
package com.ggl.fse;
import java.awt.AlphaComposite;
import java.awt.BasicStroke;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.RenderingHints;
import java.awt.Shape;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionAdapter;
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.text.DecimalFormat;
import java.util.ArrayList;
import java.util.Iterator;
import javax.imageio.ImageIO;
import javax.swing.Box;
import javax.swing.Icon;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JColorChooser;
import javax.swing.JComponent;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JSlider;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
import javax.swing.filechooser.FileNameExtensionFilter;
public class Lesson49_1 extends JFrame {
private static final long serialVersionUID = -140274271716086522L;
JMenuBar menubar;
JMenu File, Exit;
JMenuItem New, Open;
JComponent DrawingBoard;
JButton brushBut, lineBut, ellipseBut, rectBut, strokeBut, fillBut;
// Slider used to change the transparency
JSlider transSlider;
JLabel transLabel;
// Makes sure the float for transparency only shows 2 digits
DecimalFormat dec = new DecimalFormat("#.##");
// Contains all of the rules for drawing
Graphics2D graphSettings;
// Homework use graphSettings.setStroke(new BasicStroke(5F));
// To change the stroke dynamically with a component
// Going to be used to monitor what shape to draw next
int currentAction = 1;
// Transparency of the shape
float transparentVal = 1.0f;
// Default stroke and fill colors
Color strokeColor = Color.RED, fillColor = Color.WHITE;
public static void main(String[] args) {
new Lesson49_1();
}
public Lesson49_1() {
// Define the defaults for the JFrame
this.setSize(800, 600);
this.setTitle("Java Paint");
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.setJMenuBar(menubar);
JMenuBar menuBar = new JMenuBar();
// Add the menubar to the frame
setJMenuBar(menuBar);
// Define and add two drop down menu to the menubar
JMenu fileMenu = new JMenu("File");
JMenu editMenu = new JMenu("Edit");
JMenu dbMenu = new JMenu("Database");
JMenu ToolsMenu = new JMenu("Tools");
JMenu HelpMenu = new JMenu("Help");
menuBar.add(fileMenu);
menuBar.add(editMenu);
menuBar.add(dbMenu);
menuBar.add(ToolsMenu);
menuBar.add(HelpMenu);
// Create and add simple menu item to one of the drop down menu
JMenuItem newAction = new JMenuItem("New Project");
JMenuItem openAction = new JMenuItem("Open File");
JMenuItem exitAction = new JMenuItem("Quit");
JMenuItem cutAction = new JMenuItem("Cut");
JMenuItem copyAction = new JMenuItem("Copy");
JMenuItem pasteAction = new JMenuItem("Paste");
JMenuItem UndoAction = new JMenuItem("Undo");
JMenuItem RedoAction = new JMenuItem("Redo");
JMenuItem clearAction = new JMenuItem("Clear");
JMenuItem saveAction = new JMenuItem("Save");
JMenuItem exportAction = new JMenuItem("Export");
JMenuItem printAction = new JMenuItem("Print");
JMenuItem ConvertAction = new JMenuItem("Convert To Tables");
JMenuItem ColorAction = new JMenuItem("Color Picker");
JMenuItem ZoomAction = new JMenuItem("Zoom");
JMenuItem EntityAction = new JMenuItem("Entity & Attributes");
JMenuItem RelationshipAction = new JMenuItem("Relationship Attributes");
JMenuItem HelpAction = new JMenuItem("Help");
JMenuItem AboutAction = new JMenuItem("About");
fileMenu.add(newAction);
fileMenu.addSeparator();
fileMenu.add(openAction);
fileMenu.addSeparator();
fileMenu.add(saveAction);
fileMenu.addSeparator();
fileMenu.add(exportAction);
fileMenu.addSeparator();
fileMenu.add(printAction);
fileMenu.addSeparator();
fileMenu.add(exitAction);
editMenu.add(UndoAction);
editMenu.addSeparator();
editMenu.add(RedoAction);
editMenu.addSeparator();
editMenu.add(cutAction);
editMenu.addSeparator();
editMenu.add(copyAction);
editMenu.addSeparator();
editMenu.add(pasteAction);
editMenu.addSeparator();
editMenu.add(clearAction);
dbMenu.add(ConvertAction);
ToolsMenu.add(ColorAction);
ToolsMenu.addSeparator();
ToolsMenu.add(ZoomAction);
ToolsMenu.addSeparator();
ToolsMenu.add(EntityAction);
ToolsMenu.addSeparator();
ToolsMenu.add(RelationshipAction);
HelpMenu.add(HelpAction);
HelpMenu.addSeparator();
HelpMenu.add(AboutAction);
newAction.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
new Lesson49_1().setVisible(true);
}
});
JPanel buttonPanel = new JPanel();
// Swing box that will hold all the buttons
Box theBox = Box.createVerticalBox();
// Make all the buttons in makeMeButtons by passing the
// button icon.
brushBut = makeMeButtons("./src/brush.png", 1);
lineBut = makeMeButtons("./src/line.png", 2);
ellipseBut = makeMeButtons("./src/ellipse.png", 3);
rectBut = makeMeButtons("./src/rectangle.png", 4);
// Make all the buttons in makeMeColorButton by passing the
// button icon and true for stroke color or false for fill
strokeBut = makeMeColorButton("./src/stroke.png", 5, true);
fillBut = makeMeColorButton("./src/fill.png", 6, false);
// Add the buttons to the box
theBox.add(brushBut);
theBox.add(lineBut);
theBox.add(ellipseBut);
theBox.add(rectBut);
theBox.add(strokeBut);
theBox.add(fillBut);
// Add the transparent label and slider
transLabel = new JLabel("Transparent: 1");
// Min value, Max value and starting value for slider
transSlider = new JSlider(1, 99, 99);
// Create an instance of ListenForEvents to handle events
ListenForSlider lForSlider = new ListenForSlider();
// Tell Java that you want to be alerted when an event
// occurs on the slider
transSlider.addChangeListener(lForSlider);
theBox.add(transLabel);
theBox.add(transSlider);
buttonPanel.add(theBox);
this.add(buttonPanel, BorderLayout.WEST);
// Make the drawing area take up the rest of the frame
// this.add(new DrawingBoard(), BorderLayout.CENTER);
final DrawingBoard drawPanel = new DrawingBoard();
this.add(drawPanel, BorderLayout.CENTER);
this.getContentPane().setBackground(Color.WHITE);
exportAction.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
BufferedImage image = new BufferedImage(drawPanel.getWidth(),
drawPanel.getHeight(), BufferedImage.TYPE_INT_ARGB);
Graphics2D g = image.createGraphics();
drawPanel.paint(g);
g.dispose();
JFileChooser fileChooser = new JFileChooser();
File theDirectory = new File("C:/Users/Wenda/Desktop");
fileChooser.setCurrentDirectory(theDirectory);
FileNameExtensionFilter pngFilter = new FileNameExtensionFilter(
"PNG file (*.png)", "png");
fileChooser.addChoosableFileFilter(pngFilter);
fileChooser.setFileFilter(pngFilter);
int status = fileChooser.showSaveDialog(Lesson49_1.this);
if (status == JFileChooser.APPROVE_OPTION) {
try {
ImageIO.write(image, "png",
fileChooser.getSelectedFile());
JOptionPane.showMessageDialog(null, "Image saved to "
+ fileChooser.getSelectedFile().getName());
} catch (Exception ex) {
ex.printStackTrace();
}
}
}
});
// Show the frame
this.setVisible(true);
}
// Spits out buttons based on the image supplied
// actionNum represents each shape to be drawn
public JButton makeMeButtons(String iconFile, final int actionNum) {
JButton theBut = new JButton();
Icon butIcon = new ImageIcon(iconFile);
theBut.setIcon(butIcon);
// Make the proper actionPerformed method execute when the
// specific button is pressed
theBut.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
currentAction = actionNum;
}
});
return theBut;
}
// Spits out buttons based on the image supplied and
// whether a stroke or fill is to be defined
public JButton makeMeColorButton(String iconFile, final int actionNum,
final boolean stroke) {
JButton theBut = new JButton();
Icon butIcon = new ImageIcon(iconFile);
theBut.setIcon(butIcon);
theBut.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
if (stroke) {
// JColorChooser is a popup that lets you pick a color
strokeColor = JColorChooser.showDialog(null,
"Pick a Stroke", Color.BLACK);
} else {
fillColor = JColorChooser.showDialog(null, "Pick a Fill",
Color.WHITE);
}
}
});
return theBut;
}
public class DrawingBoard extends JComponent {
private static final long serialVersionUID = -4431176095451940075L;
// ArrayLists that contain each shape drawn along with
// that shapes stroke and fill
ArrayList<Shape> shapes = new ArrayList<Shape>();
ArrayList<Color> shapeFill = new ArrayList<Color>();
ArrayList<Color> shapeStroke = new ArrayList<Color>();
ArrayList<Float> transPercent = new ArrayList<Float>();
Point drawStart, drawEnd;
// Monitors events on the drawing area of the frame
public DrawingBoard() {
this.addMouseListener(new MouseAdapter() {
public void mousePressed(MouseEvent e) {
if (currentAction != 1) {
// When the mouse is pressed get x & y position
drawStart = new Point(e.getX(), e.getY());
drawEnd = drawStart;
repaint();
}
}
public void mouseReleased(MouseEvent e) {
if (currentAction != 1) {
// Create a shape using the starting x & y
// and finishing x & y positions
Shape aShape = null;
if (currentAction == 2) {
aShape = drawLine(drawStart.x, drawStart.y,
e.getX(), e.getY());
} else
if (currentAction == 3) {
aShape = drawEllipse(drawStart.x, drawStart.y,
e.getX(), e.getY());
} else
if (currentAction == 4) {
// Create a new rectangle using x & y coordinates
aShape = drawRectangle(drawStart.x, drawStart.y,
e.getX(), e.getY());
}
// Add shapes, fills and colors to there ArrayLists
shapes.add(aShape);
shapeFill.add(fillColor);
shapeStroke.add(strokeColor);
// Add transparency value to ArrayList
transPercent.add(transparentVal);
drawStart = null;
drawEnd = null;
// repaint the drawing area
repaint();
}
}
});
this.addMouseMotionListener(new MouseMotionAdapter() {
public void mouseDragged(MouseEvent e) {
// If this is a brush have shapes go on the screen quickly
if (currentAction == 1) {
int x = e.getX();
int y = e.getY();
Shape aShape = null;
// Make stroke and fill equal to eliminate the fact that
// this is an ellipse
strokeColor = fillColor;
aShape = drawBrush(x, y, 5, 5);
shapes.add(aShape);
shapeFill.add(fillColor);
shapeStroke.add(strokeColor);
// Add the transparency value
transPercent.add(transparentVal);
}
// Get the final x & y position after the mouse is dragged
drawEnd = new Point(e.getX(), e.getY());
repaint();
}
});
}
public void paint(Graphics g) {
// Class used to define the shapes to be drawn
graphSettings = (Graphics2D) g;
// Antialiasing cleans up the jagged lines and defines rendering
// rules
graphSettings.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
// Defines the line width of the stroke
graphSettings.setStroke(new BasicStroke(4));
// Iterators created to cycle through strokes and fills
Iterator<Color> strokeCounter = shapeStroke.iterator();
Iterator<Color> fillCounter = shapeFill.iterator();
// Iterator for transparency
Iterator<Float> transCounter = transPercent.iterator();
for (Shape s : shapes) {
// Sets the shapes transparency value
graphSettings.setComposite(AlphaComposite.getInstance(
AlphaComposite.SRC_OVER, transCounter.next()));
// Grabs the next stroke from the color arraylist
graphSettings.setPaint(strokeCounter.next());
graphSettings.draw(s);
// Grabs the next fill from the color arraylist
graphSettings.setPaint(fillCounter.next());
graphSettings.fill(s);
}
// Guide shape used for drawing
if (drawStart != null && drawEnd != null) {
// Makes the guide shape transparent
graphSettings.setComposite(AlphaComposite.getInstance(
AlphaComposite.SRC_OVER, 0.40f));
// Make guide shape gray for professional look
graphSettings.setPaint(Color.LIGHT_GRAY);
Shape aShape = null;
if (currentAction == 2) {
aShape = drawLine(drawStart.x, drawStart.y, drawEnd.x,
drawEnd.y);
} else
if (currentAction == 3) {
aShape = drawEllipse(drawStart.x, drawStart.y, drawEnd.x,
drawEnd.y);
} else
if (currentAction == 4) {
// Create a new rectangle using x & y coordinates
aShape = drawRectangle(drawStart.x, drawStart.y, drawEnd.x,
drawEnd.y);
}
graphSettings.draw(aShape);
}
}
private Rectangle2D.Float drawRectangle(int x1, int y1, int x2, int y2) {
// Get the top left hand corner for the shape
// Math.min returns the points closest to 0
int x = Math.min(x1, x2);
int y = Math.min(y1, y2);
// Gets the difference between the coordinates and
int width = Math.abs(x1 - x2);
int height = Math.abs(y1 - y2);
return new Rectangle2D.Float(x, y, width, height);
}
// The other shapes will work similarly
// More on this in the next tutorial
private Ellipse2D.Float drawEllipse(int x1, int y1, int x2, int y2) {
int x = Math.min(x1, x2);
int y = Math.min(y1, y2);
int width = Math.abs(x1 - x2);
int height = Math.abs(y1 - y2);
return new Ellipse2D.Float(x, y, width, height);
}
private Line2D.Float drawLine(int x1, int y1, int x2, int y2) {
return new Line2D.Float(x1, y1, x2, y2);
}
private Ellipse2D.Float drawBrush(int x1, int y1, int brushStrokeWidth,
int brushStrokeHeight) {
return new Ellipse2D.Float(x1, y1, brushStrokeWidth,
brushStrokeHeight);
}
}
// Implements ActionListener so it can react to events on components
private class ListenForSlider implements ChangeListener {
// Called when the spinner is changed
public void stateChanged(ChangeEvent e) {
// Check if the source of the event was the button
if (e.getSource() == transSlider) {
// Change the value for the label next to the spinner
// Use decimal format to make sure only 2 decimals are ever
// displayed
transLabel.setText("Transparent: "
+ dec.format(transSlider.getValue() * .01));
// Set the value for transparency for every shape drawn after
transparentVal = (float) (transSlider.getValue() * .01);
}
}
}
}