sketchframe.java

JAVA 2入门经典 练习答案

      }
      statusBar.setColorPane(elementColor);
    }

    // The arrays below could be put in the Constants interface definition
    private final String[] choices = {"Red", "Yellow", "Green", "Blue", "Custom..." };
    private final Color[] colors = {Color.RED, Color.YELLOW, Color.GREEN, Color.BLUE};
  }

  // We will add inner classes defining action objects here...
  class FileAction extends AbstractAction {    
    // Constructor
    FileAction(String name) {
      super(name);
      String iconFileName = "Images/" + name + ".gif";
      if(new File(iconFileName).exists())
        putValue(SMALL_ICON, new ImageIcon(iconFileName));
    }

   // Constructor
    FileAction(String name, KeyStroke keystroke) {
      this(name);
      if(keystroke != null)
        putValue(ACCELERATOR_KEY, keystroke);
    }

    FileAction(String name, String tooltip) {
      this(name);                                // Call the other constructor
      if(tooltip != null)                        // If there is tooltip text
        putValue(SHORT_DESCRIPTION, tooltip);    // ...squirrel it away
    }

    FileAction(String name, KeyStroke keystroke, String tooltip) {
      this(name, keystroke);                         // Call the other constructor
      if(tooltip != null)                             // If there is tooltip text
        putValue(SHORT_DESCRIPTION, tooltip);         // ...squirrel it away
    }
    
    // Event handler
    public void actionPerformed(ActionEvent e) {
      // We will add action code here eventually...
    }
  }

  class TypeAction extends AbstractAction {    
    TypeAction(String name, int typeID) {
      super(name);
      this.typeID = typeID;
      String iconFileName = "Images/" + name + ".gif";
      if(new File(iconFileName).exists())
        putValue(SMALL_ICON, new ImageIcon(iconFileName));
    }
    
    TypeAction(String name, int typeID, String tooltip) {
      this(name, typeID);
      if(tooltip != null)                               // If there is a tooltip
        putValue(SHORT_DESCRIPTION, tooltip);           // ...squirrel it away
    }

    public void actionPerformed(ActionEvent e) {
      elementType = typeID;  
      statusBar.setTypePane(typeID);
    }

    private int typeID;
  }

  // Handles color menu items
  class ColorAction  extends AbstractAction {
    public ColorAction(String name, Color color) {
      super(name);
      this.color = color;
      String iconFileName = "Images/" + name + ".gif";
      if(new File(iconFileName).exists())
        putValue(SMALL_ICON, new ImageIcon(iconFileName));
    }
    
    public ColorAction(String name, Color color, String tooltip) {
      this(name, color);
       if(tooltip != null)                               // If there is a tooltip
         putValue(SHORT_DESCRIPTION, tooltip);           // ...squirrel it away
    }
    
    public void actionPerformed(ActionEvent e) {
      elementColor = color;
      statusBar.setColorPane(color);
    }

    private Color color;
  }

  private JMenuItem addMenuItem(JMenu menu, Action action) {
    JMenuItem item = menu.add(action);                  // Add the menu item

    KeyStroke keystroke = (KeyStroke)action.getValue(action.ACCELERATOR_KEY);
    if(keystroke != null)
      item.setAccelerator(keystroke);
      
    // remove this comments to disable icons
    // item.setIcon(null);                                 // Remove the icon
    return item;                                        // Return the menu item
  }

  public Color getElementColor() { 
    return elementColor; 
  }

  public void setElementColor(Color color) {
    elementColor = color;
    statusBar.setColorPane(color);
  }

  public int getElementType() { 
    return elementType; 
  }

  // Handle About menu action events
  public void actionPerformed(ActionEvent e)  {
    if(e.getSource() == aboutItem) {
      // Create about dialog with the menu item as parent
      JOptionPane.showMessageDialog(this,                          // Parent
                            "Sketcher Copyright Ivor Horton 2001", // Message
                            "About Sketcher",                      // Title
                            JOptionPane.INFORMATION_MESSAGE);      // Message type

    } else if(e.getSource() == fontItem) {      // Set the dialog window position
      Rectangle bounds = getBounds();
      fontDlg.setLocation(bounds.x + bounds.width/3, bounds.y + bounds.height/3);
      fontDlg.setVisible(true);            // Show the dialog

    } else if(e.getSource() == customColorItem) {
      Color color = JColorChooser.showDialog(this, "Select Custom Color",
                                                           elementColor);
      if(color != null) {
        elementColor = color;
        statusBar.setColorPane(color);
      }
    }
  }

  public Font getCurrentFont() {  
    return font;  
  }

  public void setCurrentFont(Font font) {  
    this.font = font;  
  }

  private JPopupMenu popup = new JPopupMenu("General");       // Window pop-up

  // Element color actions
  private ColorAction redAction, yellowAction, greenAction, blueAction;

  // Element type actions
  private TypeAction lineAction, rectangleAction, circleAction, curveAction, textAction;

  // File actions
  private FileAction newAction, openAction, closeAction, saveAction, saveAsAction, printAction;

  private JMenuBar menuBar = new JMenuBar();     // Window menu bar

  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
  private Sketcher theApp;

  private StatusBar statusBar = new StatusBar();    // Window status bar

  // Sundry menu items
  private JMenuItem aboutItem, fontItem;
  private Font font = DEFAULT_FONT;                      // Current font

  private FontDialog fontDlg;                           // The font dialog
 
    // Class defining a general purpose message box
  class AboutDialog extends JDialog implements ActionListener   {
    public AboutDialog(Frame parent, String title, String message)  {
      super(parent, title, true);
      // If there was a parent, set dialog position inside
      if(parent != null) {
        Dimension parentSize = parent.getSize();     // Parent size
        Point p = parent.getLocation();              // Parent position
        setLocation(p.x+parentSize.width/4,p.y+parentSize.height/4); 
      }

      // Create the message pane
      JPanel messagePane = new JPanel();
      messagePane.add(new JLabel(message));        
      getContentPane().add(messagePane);

      // Create the button pane
      JPanel buttonPane = new JPanel();
      JButton button = new JButton("OK");        // Create OK button
      buttonPane.add(button);                    // add to content pane
      button.addActionListener(this);
      getContentPane().add(buttonPane, BorderLayout.SOUTH);
      setDefaultCloseOperation(DISPOSE_ON_CLOSE);
      pack();                                    // Size window for components
      setVisible(true);
    }

    // OK button action
    public void actionPerformed(ActionEvent e)  {
      setVisible(false);                         // Set dialog invisible
      dispose();                                 // Release the dialog resources
    }
  }
  private JMenuItem customColorItem;
}