Java基础之处理事件——添加菜单图标（Sketcher 8 with toolbar buttons and menu icons）

控制台程序。

要为菜单项添加图标以补充工具栏图标，只需要在创建菜单项的Action对象中添加IconImage对象，作为SMALL_ICON键的值即可。

 // Defines application wide constants
 package Constants;
 import java.awt.Color;
 import javax.swing.*;

 public class SketcherConstants {
   // Path for images
   public final static String imagePath = "E:/JavaProject/BeginningJava/Images/";

   // Toolbar icons
   public final static Icon NEW24 = new ImageIcon(imagePath + "New24.gif");
   public final static Icon OPEN24 = new ImageIcon(imagePath + "Open24.gif");
   public final static Icon SAVE24 = new ImageIcon(imagePath + "Save24.gif");
   public final static Icon SAVEAS24 = new ImageIcon(imagePath + "SaveAs24.gif");
   public final static Icon PRINT24 = new ImageIcon(imagePath + "Print24.gif");

   public final static Icon LINE24 = new ImageIcon(imagePath + "Line24.gif");
   public final static Icon RECTANGLE24 = new ImageIcon(imagePath + "Rectangle24.gif");
   public final static Icon CIRCLE24 = new ImageIcon(imagePath + "Circle24.gif");
   public final static Icon CURVE24 = new ImageIcon(imagePath + "Curve24.gif");

   public final static Icon RED24 = new ImageIcon(imagePath + "Red24.gif");
   public final static Icon GREEN24 = new ImageIcon(imagePath + "Green24.gif");
   public final static Icon BLUE24 = new ImageIcon(imagePath + "Blue24.gif");
   public final static Icon YELLOW24 = new ImageIcon(imagePath + "Yellow24.gif");

   // Menu item icons
   public final static Icon NEW16 = new ImageIcon(imagePath + "new16.gif");
   public final static Icon OPEN16 = new ImageIcon(imagePath + "Open16.gif");
   public final static Icon SAVE16 = new ImageIcon(imagePath + "Save16.gif");
   public final static Icon SAVEAS16 = new ImageIcon(imagePath + "SaveAs16.gif");
   public final static Icon PRINT16 = new ImageIcon(imagePath + "print16.gif");

   public final static Icon LINE16 = new ImageIcon(imagePath + "Line16.gif");
   public final static Icon RECTANGLE16 = new ImageIcon(imagePath + "Rectangle16.gif");
   public final static Icon CIRCLE16 = new ImageIcon(imagePath + "Circle16.gif");
   public final static Icon CURVE16 = new ImageIcon(imagePath + "Curve16.gif");

   public final static Icon RED16 = new ImageIcon(imagePath + "Red16.gif");
   public final static Icon GREEN16 = new ImageIcon(imagePath + "Green16.gif");
   public final static Icon BLUE16 = new ImageIcon(imagePath + "Blue16.gif");
   public final static Icon YELLOW16 = new ImageIcon(imagePath + "Yellow16.gif");

   // Element type definitions
   public final static int LINE      = 101;
   public final static int RECTANGLE = 102;
   public final static int CIRCLE    = 103;
   public final static int CURVE     = 104;

   // Initial conditions
   public final static int DEFAULT_ELEMENT_TYPE = LINE;
   public final static Color DEFAULT_ELEMENT_COLOR = Color.BLUE;
 }

 // Frame for the Sketcher application
 import javax.swing.*;
 import javax.swing.border.*;
 import java.awt.event.*;
 import java.awt.*;

 import static java.awt.event.InputEvent.*;
 import static java.awt.AWTEvent.*;
 import static java.awt.Color.*;
 import static Constants.SketcherConstants.*;
 import static javax.swing.Action.*;

 @SuppressWarnings("serial")
 public class SketcherFrame extends JFrame {
   // Constructor
   public SketcherFrame(String title) {
     setTitle(title);                                                   // Set the window title
     setJMenuBar(menuBar);                                              // Add the menu bar to the window
     setDefaultCloseOperation(EXIT_ON_CLOSE);                           // Default is exit the application

     createFileMenu();                                                  // Create the File menu
     createElementMenu();                                               // Create the element menu
     createColorMenu();                                                 // Create the element menu
     createToolbar();
     toolBar.setRollover(true);
     getContentPane().add(toolBar, BorderLayout.NORTH);
   }

   // Create File menu item actions
   private void createFileMenuActions() {
     newAction = new FileAction("New", 'N', CTRL_DOWN_MASK);
     openAction = new FileAction("Open", 'O', CTRL_DOWN_MASK);
     closeAction = new FileAction("Close");
     saveAction = new FileAction("Save", 'S', CTRL_DOWN_MASK);
     saveAsAction = new FileAction("Save As...");
     printAction = new FileAction("Print", 'P', CTRL_DOWN_MASK);
     exitAction = new FileAction("Exit", 'X', CTRL_DOWN_MASK);

     // Initialize the array
     FileAction[] actions = {openAction, closeAction, saveAction, saveAsAction, printAction, exitAction};
     fileActions = actions;

     // Add toolbar icons
     newAction.putValue(LARGE_ICON_KEY, NEW24);
     openAction.putValue(LARGE_ICON_KEY, OPEN24);
     saveAction.putValue(LARGE_ICON_KEY, SAVE24);
     saveAsAction.putValue(LARGE_ICON_KEY, SAVEAS24);
     printAction.putValue(LARGE_ICON_KEY, PRINT24);

     // Add menu item icons
     newAction.putValue(SMALL_ICON, NEW16);
     openAction.putValue(SMALL_ICON, OPEN16);
     saveAction.putValue(SMALL_ICON, SAVE16);
     saveAsAction.putValue(SMALL_ICON,SAVEAS16);
     printAction.putValue(SMALL_ICON, PRINT16);
   }

   // Create the File menu
   private void createFileMenu() {
     JMenu fileMenu = new JMenu("File");                                // Create File menu
     fileMenu.setMnemonic('F');                                         // Create shortcut
     createFileMenuActions();                                           // Create Actions for File menu item

     // Construct the file drop-down menu
     fileMenu.add(newAction);                                           // New Sketch menu item
     fileMenu.add(openAction);                                          // Open sketch menu item
     fileMenu.add(closeAction);                                         // Close sketch menu item
     fileMenu.addSeparator();                                           // Add separator
     fileMenu.add(saveAction);                                          // Save sketch to file
     fileMenu.add(saveAsAction);                                        // Save As menu item
     fileMenu.addSeparator();                                           // Add separator
     fileMenu.add(printAction);                                         // Print sketch menu item
     fileMenu.addSeparator();                                           // Add separator
     fileMenu.add(exitAction);                                          // Print sketch menu item
     menuBar.add(fileMenu);                                             // Add the file menu
   }

   // Create Element  menu actions
   private void createElementTypeActions() {
     lineAction = new TypeAction("Line", LINE, 'L', CTRL_DOWN_MASK);
     rectangleAction = new TypeAction("Rectangle", RECTANGLE, 'R', CTRL_DOWN_MASK);
     circleAction =  new TypeAction("Circle", CIRCLE,'C', CTRL_DOWN_MASK);
     curveAction = new TypeAction("Curve", CURVE,'U', CTRL_DOWN_MASK);

     // Initialize the array
     TypeAction[] actions = {lineAction, rectangleAction, circleAction, curveAction};
     typeActions = actions;

     // Add toolbar icons
     lineAction.putValue(LARGE_ICON_KEY, LINE24);
     rectangleAction.putValue(LARGE_ICON_KEY, RECTANGLE24);
     circleAction.putValue(LARGE_ICON_KEY, CIRCLE24);
     curveAction.putValue(LARGE_ICON_KEY, CURVE24);

     // Add menu item icons
     lineAction.putValue(SMALL_ICON, LINE16);
     rectangleAction.putValue(SMALL_ICON, RECTANGLE16);
     circleAction.putValue(SMALL_ICON, CIRCLE16);
     curveAction.putValue(SMALL_ICON, CURVE16);
   }

   // Create the Elements menu
   private void createElementMenu() {
     createElementTypeActions();
     elementMenu = new JMenu("Elements");                               // Create Elements menu
     elementMenu.setMnemonic('E');                                      // Create shortcut
     createRadioButtonDropDown(elementMenu, typeActions, lineAction);
     menuBar.add(elementMenu);                                          // Add the element menu
   }

   // Create Color menu actions
   private void createElementColorActions() {
     redAction = new ColorAction("Red", RED, 'R', CTRL_DOWN_MASK|ALT_DOWN_MASK);
     yellowAction = new ColorAction("Yellow", YELLOW, 'Y', CTRL_DOWN_MASK|ALT_DOWN_MASK);
     greenAction = new ColorAction("Green", GREEN, 'G', CTRL_DOWN_MASK|ALT_DOWN_MASK);
     blueAction = new ColorAction("Blue", BLUE, 'B', CTRL_DOWN_MASK|ALT_DOWN_MASK);

     // Initialize the array
     ColorAction[] actions = {redAction, greenAction, blueAction, yellowAction};
     colorActions = actions;

     // Add toolbar icons
     redAction.putValue(LARGE_ICON_KEY, RED24);
     greenAction.putValue(LARGE_ICON_KEY, GREEN24);
     blueAction.putValue(LARGE_ICON_KEY, BLUE24);
     yellowAction.putValue(LARGE_ICON_KEY, YELLOW24);

     // Add menu item icons
     redAction.putValue(SMALL_ICON, RED16);
     greenAction.putValue(SMALL_ICON, GREEN16);
     blueAction.putValue(SMALL_ICON, BLUE16);
     yellowAction.putValue(SMALL_ICON, YELLOW16);
   }

   // Create the Color menu
   private void createColorMenu() {
     createElementColorActions();
     colorMenu = new JMenu("Color");                                    // Create Elements menu
     colorMenu.setMnemonic('C');                                        // Create shortcut
     createRadioButtonDropDown(colorMenu, colorActions, blueAction);
     menuBar.add(colorMenu);                                            // Add the color menu
   }

   // Menu creation helper
   private void createRadioButtonDropDown(JMenu menu, Action[] actions, Action selected) {
     ButtonGroup group = new ButtonGroup();
     JRadioButtonMenuItem item = null;
     for(Action action : actions) {
       group.add(menu.add(item = new JRadioButtonMenuItem(action)));
       if(action == selected) {
         item.setSelected(true);                                        // This is default selected
       }
     }
   }

   // Create toolbar buttons on the toolbar
   private void createToolbar() {
     for(FileAction action: fileActions){
       if(action != exitAction && action != closeAction)
         addToolbarButton(action);                                      // Add the toolbar button
     }
     toolBar.addSeparator();

     // Create Color menu buttons
     for(ColorAction action:colorActions){
         addToolbarButton(action);                                      // Add the toolbar button
     }
     toolBar.addSeparator();

     // Create Elements menu buttons
     for(TypeAction action:typeActions){
         addToolbarButton(action);                                      // Add the toolbar button
     }
  }

   // Create and add a toolbar button
   private void addToolbarButton(Action action) {
     JButton button = new JButton(action);                              // Create from Action
     button.setBorder(BorderFactory.createCompoundBorder(               // Add button border
            new EmptyBorder(2,5,5,2),                                   // Outside border
            BorderFactory.createRaisedBevelBorder()));                  // Inside border
     button.setHideActionText(true);                                    // No label on the button
     toolBar.add(button);                                               // Add the toolbar button
   }

   // Set radio button menu checks
   private void setChecks(JMenu menu, Object eventSource) {
     if(eventSource instanceof JButton){
       JButton button = (JButton)eventSource;
       Action action = button.getAction();
       for(int i = 0 ; i < menu.getItemCount() ; ++i) {
         JMenuItem item = menu.getItem(i);
         item.setSelected(item.getAction() == action);
       }
     }
   }

   // Inner class defining Action objects for File menu items
   class FileAction extends AbstractAction {
     // Create action with a name
     FileAction(String name) {
       super(name);
     }

     // Create action with a name and accelerator
     FileAction(String name, char ch, int modifiers) {
       super(name);
       putValue(ACCELERATOR_KEY, KeyStroke.getKeyStroke(ch, modifiers));

       // Now find the character to underline
       int index = name.toUpperCase().indexOf(ch);
       if(index != -1) {
         putValue(DISPLAYED_MNEMONIC_INDEX_KEY, index);
       }
     }

     // Event handler
     public void actionPerformed(ActionEvent e) {
       // You will add action code here eventually...
     }
   }

   // Inner class defining Action objects for Element type menu items
   class TypeAction extends AbstractAction {
     // Create action with just a name property
     TypeAction(String name, int typeID) {
       super(name);
       this.typeID = typeID;
     }

     // Create action with a name and an accelerator
     private TypeAction(String name,int typeID, char ch, int modifiers) {
       this(name, typeID);
       putValue(ACCELERATOR_KEY, KeyStroke.getKeyStroke(ch, modifiers));

       // Now find the character to underline
       int index = name.toUpperCase().indexOf(ch);
       if(index != -1) {
         putValue(DISPLAYED_MNEMONIC_INDEX_KEY, index);
       }
     }

     public void actionPerformed(ActionEvent e) {
       elementType = typeID;
       setChecks(elementMenu, e.getSource());
     }

     private int typeID;
   }

   // Handles color menu items
   class ColorAction  extends AbstractAction {
     // Create an action with a name and a color
     public ColorAction(String name, Color color) {
       super(name);
       this.color = color;
     }

     // Create an action with a name, a color, and an accelerator
     public ColorAction(String name, Color color, char ch, int modifiers) {
       this(name, color);
       putValue(ACCELERATOR_KEY, KeyStroke.getKeyStroke(ch, modifiers));

       // Now find the character to underline
       int index = name.toUpperCase().indexOf(ch);
       if(index != -1) {
         putValue(DISPLAYED_MNEMONIC_INDEX_KEY, index);
       }
     }

     public void actionPerformed(ActionEvent e) {
       elementColor = color;
       setChecks(colorMenu, e.getSource());
     }

     private Color color;
   }

   // File actions
   private FileAction newAction, openAction, closeAction, saveAction, saveAsAction, printAction, exitAction;
   private FileAction[] fileActions;                                    // File actions as an array

   // Element type actions
   private TypeAction lineAction, rectangleAction, circleAction, curveAction;
   private TypeAction[] typeActions;                                    // Type actions as an array

 // Element color actions
   private ColorAction redAction, yellowAction,greenAction, blueAction;
   private ColorAction[] colorActions;                                  // Color actions as an array

   private JMenuBar menuBar = new JMenuBar();                           // Window menu bar
   private JMenu elementMenu;                                           // Elements menu
   private JMenu colorMenu;                                             // Color menu

   private Color elementColor = DEFAULT_ELEMENT_COLOR;                  // Current element color
   private int elementType = DEFAULT_ELEMENT_TYPE;                      // Current element type
   private JToolBar toolBar = new JToolBar();                           // Window toolbar
 }

 // Sketching application
 import javax.swing.*;
 import java.awt.*;
 import java.awt.event.*;

 public class Sketcher {
   public static void main(String[] args) {
      theApp = new Sketcher();                                          // Create the application object
    SwingUtilities.invokeLater(new Runnable() {
             public void run() {
                           theApp.createGUI();                          // Call GUI creator
             }
         });
   }

   // Method to create the application GUI
   private void createGUI() {
     window = new SketcherFrame("Sketcher");                            // Create the app window
     Toolkit theKit = window.getToolkit();                              // Get the window toolkit
     Dimension wndSize = theKit.getScreenSize();                        // Get screen size

     // Set the position to screen center & size to half screen size
     window.setSize(wndSize.width/2, wndSize.height/2);                 // Set window size
     window.setLocationRelativeTo(null);                                // Center window

     window.addWindowListener(new WindowHandler());                     // Add window listener
     window.setVisible(true);
   }

   // Handler class for window events
   class WindowHandler extends WindowAdapter {
     // Handler for window closing event
     @Override
     public void windowClosing(WindowEvent e) {
       // Code to be added here...
     }
   }

   private SketcherFrame window;                                        // The application window
   private static Sketcher theApp;                                      // The application object
 }