所以我有一个GUI Imageviewer，我已经浏览了这本书并在网上找不到任何关于如何使菜单工具栏垂直的信息。我希望文件，过滤器和帮助只显示在左侧的verticlaly。真的很挣扎。建议？
import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
import javax.swing.*;
import javax.swing.border.*;
import java.io.File;
import java.util.List;
import java.util.ArrayList;
import java.util.Iterator;
/**
* ImageViewer is the main class of the image viewer application. It builds and
* displays the application GUI and initialises all other components.
*
* To start the application, create an object of this class.
*
* @author Michael Kölling and David J. Barnes.
* @version 3.1
*/
public class ImageViewer
// fields:
private JFrame frame;
private ImagePanel imagePanel;
private JLabel filenameLabel;
private JLabel statusLabel;
private JButton smallerButton;
private JButton largerButton;
private OFImage currentImage;
private List<Filter> filters;
/**
* Create an ImageViewer and display its GUI on screen.
*/
public ImageViewer()
{
currentImage = null;
filters = createFilters();
makeFrame();
}
// ---- implementation of menu functions ----
/**
* Open function: open a file chooser to select a new image file,
* and then display the chosen image.
*/
private void openFile()
{
int returnVal = fileChooser.showOpenDialog(frame);
if(returnVal != JFileChooser.APPROVE_OPTION) {
return; // cancelled
}
File selectedFile = fileChooser.getSelectedFile();
currentImage = ImageFileManager.loadImage(selectedFile);
if(currentImage == null) { // image file was not a valid image
JOptionPane.showMessageDialog(frame,
"The file was not in a recognized image file format.",
"Image Load Error",
JOptionPane.ERROR_MESSAGE);
return;
}
imagePanel.setImage(currentImage);
setButtonsEnabled(true);
showFilename(selectedFile.getPath());
showStatus("File loaded.");
frame.pack();
}
/**
* Close function: close the current image.
*/
private void close()
{
currentImage = null;
imagePanel.clearImage();
showFilename(null);
setButtonsEnabled(false);
}
/**
* Save As function: save the current image to a file.
*/
private void saveAs()
{
if(currentImage != null) {
int returnVal = fileChooser.showSaveDialog(frame);
if(returnVal != JFileChooser.APPROVE_OPTION) {
return; // cancelled
}
File selectedFile = fileChooser.getSelectedFile();
ImageFileManager.saveImage(currentImage, selectedFile);
showFilename(selectedFile.getPath());
}
}
/**
* Quit function: quit the application.
*/
private void quit()
{
System.exit(0);
}
/**
* Apply a given filter to the current image.
*
* @param filter The filter object to be applied.
*/
private void applyFilter(Filter filter)
{
if(currentImage != null) {
filter.apply(currentImage);
frame.repaint();
showStatus("Applied: " + filter.getName());
}
else {
showStatus("No image loaded.");
}
}
/**
* 'About' function: show the 'about' box.
*/
private void showAbout()
{
JOptionPane.showMessageDialog(frame,
"ImageViewer\n" + VERSION,
"About ImageViewer",
JOptionPane.INFORMATION_MESSAGE);
}
/**
* Make the current picture larger.
*/
private void makeLarger()
{
if(currentImage != null) {
// create new image with double size
int width = currentImage.getWidth();
int height = currentImage.getHeight();
OFImage newImage = new OFImage(width * 2, height * 2);
// copy pixel data into new image
for(int y = 0; y < height; y++) {
for(int x = 0; x < width; x++) {
Color col = currentImage.getPixel(x, y);
newImage.setPixel(x * 2, y * 2, col);
newImage.setPixel(x * 2 + 1, y * 2, col);
newImage.setPixel(x * 2, y * 2 + 1, col);
newImage.setPixel(x * 2+1, y * 2 + 1, col);
}
}
currentImage = newImage;
imagePanel.setImage(currentImage);
frame.pack();
}
}
/**
* Make the current picture smaller.
*/
private void makeSmaller()
{
if(currentImage != null) {
// create new image with double size
int width = currentImage.getWidth() / 2;
int height = currentImage.getHeight() / 2;
OFImage newImage = new OFImage(width, height);
// copy pixel data into new image
for(int y = 0; y < height; y++) {
for(int x = 0; x < width; x++) {
newImage.setPixel(x, y, currentImage.getPixel(x * 2, y * 2));
}
}
currentImage = newImage;
imagePanel.setImage(currentImage);
frame.pack();
}
}
// ---- support methods ----
/**
* Show the file name of the current image in the fils display label.
* 'null' may be used as a parameter if no file is currently loaded.
*
* @param filename The file name to be displayed, or null for 'no file'.
*/
private void showFilename(String filename)
{
if(filename == null) {
filenameLabel.setText("No file displayed.");
}
else {
filenameLabel.setText("File: " + filename);
}
}
/**
* Show a message in the status bar at the bottom of the screen.
* @param text The status message.
*/
private void showStatus(String text)
{
statusLabel.setText(text);
}
/**
* Enable or disable all toolbar buttons.
*
* @param status 'true' to enable the buttons, 'false' to disable.
*/
private void setButtonsEnabled(boolean status)
{
smallerButton.setEnabled(status);
largerButton.setEnabled(status);
}
/**
* Create a list with all the known filters.
* @return The list of filters.
*/
private List<Filter> createFilters()
{
List<Filter> filterList = new ArrayList<Filter>();
filterList.add(new DarkerFilter("Darker"));
filterList.add(new LighterFilter("Lighter"));
filterList.add(new ThresholdFilter("Threshold"));
filterList.add(new InvertFilter("Invert"));
filterList.add(new SolarizeFilter("Solarize"));
filterList.add(new SmoothFilter("Smooth"));
filterList.add(new PixelizeFilter("Pixelize"));
filterList.add(new MirrorFilter("Mirror"));
filterList.add(new GrayScaleFilter("Grayscale"));
filterList.add(new EdgeFilter("Edge Detection"));
filterList.add(new FishEyeFilter("Fish Eye"));
return filterList;
}
// ---- Swing stuff to build the frame and all its components and menus ----
/**
* Create the Swing frame and its content.
*/
private void makeFrame()
{
frame = new JFrame("ImageViewer");
JPanel contentPane = (JPanel)frame.getContentPane();
contentPane.setBorder(new EmptyBorder(12, 12, 12, 12));
makeMenuBar(frame);
// Specify the layout manager with nice spacing
contentPane.setLayout(new BorderLayout(6, 6));
// Create the image pane in the center
imagePanel = new ImagePanel();
imagePanel.setBorder(new EtchedBorder());
contentPane.add(imagePanel, BorderLayout.CENTER);
// Create two labels at top and bottom for the file name and status messages
filenameLabel = new JLabel();
contentPane.add(filenameLabel, BorderLayout.NORTH);
statusLabel = new JLabel(VERSION);
contentPane.add(statusLabel, BorderLayout.SOUTH);
// Create the toolbar with the buttons
JPanel toolbar = new JPanel();
toolbar.setLayout(new GridLayout(0, 1));
smallerButton = new JButton("Smaller");
smallerButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) { makeSmaller(); }
});
toolbar.add(smallerButton);
largerButton = new JButton("Larger");
largerButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) { makeLarger(); }
});
toolbar.add(largerButton);
// Add toolbar into panel with flow layout for spacing
JPanel flow = new JPanel();
flow.add(toolbar);
contentPane.add(flow, BorderLayout.WEST);
// building is done - arrange the components
showFilename(null);
setButtonsEnabled(false);
frame.pack();
// place the frame at the center of the screen and show
Dimension d = Toolkit.getDefaultToolkit().getScreenSize();
frame.setLocation(d.width/2 - frame.getWidth()/2, d.height/2 - frame.getHeight()/2);
frame.setVisible(true);
}
/**
* Create the main frame's menu bar.
*
* @param frame The frame that the menu bar should be added to.
*/
private void makeMenuBar(JFrame frame)
{
final int SHORTCUT_MASK =
Toolkit.getDefaultToolkit().getMenuShortcutKeyMask();
JMenuBar menubar = new JMenuBar();
frame.setJMenuBar(menubar);
JMenu menu;
JMenuItem item;
// create the File menu
menu = new JMenu("File");
menubar.add(menu);
item = new JMenuItem("Open...");
item.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_O, SHORTCUT_MASK));
item.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) { openFile(); }
});
menu.add(item);
item = new JMenuItem("Close");
item.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_W, SHORTCUT_MASK));
item.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) { close(); }
});
menu.add(item);
menu.addSeparator();
item = new JMenuItem("Save As...");
item.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_S, SHORTCUT_MASK));
item.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) { saveAs(); }
});
menu.add(item);
menu.addSeparator();
item = new JMenuItem("Quit");
item.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_Q, SHORTCUT_MASK));
item.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) { quit(); }
});
menu.add(item);
// create the Filter menu
menu = new JMenu("Filter");
menubar.add(menu);
for(final Filter filter : filters) {
item = new JMenuItem(filter.getName());
item.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
applyFilter(filter);
}
});
menu.add(item);
}
// create the Help menu
menu = new JMenu("Help");
menubar.add(menu);
item = new JMenuItem("About ImageViewer...");
item.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) { showAbout(); }
});
menu.add(item);
}
}