fontdialog.java

非常好的java事例以及带源码事例的java2教程

// Class to define a dialog to choose a font

import java.awt.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.border.*;
import java.awt.event.*;

class FontDialog extends JDialog
                implements Constants,
                           ActionListener,        // For buttons etc
                           ListSelectionListener  // For list box
  {
    // Constructor
    public FontDialog(SketchFrame window)
    {
      // Call the base constructor to create a modal dialog
      super(window, "Font Selection", true);   
 
      this.window = window;                          // Save the window reference
      font = window.getCurrentFont();                // Get the current font
      fontStyle = font.getStyle();                   // ...style
      fontSize = font.getSize();                     // ...and size

      // Create the dialog button panel 
      JPanel buttonPane = new JPanel();             // Create the panel to hold buttons
  
      // Create and add the buttons to the buttonPane
      buttonPane.add(ok = createButton("OK"));              // Add the OK button
      buttonPane.add(cancel = createButton("Cancel"));      // Add the Cancel button
      getContentPane().add(buttonPane, BorderLayout.SOUTH); // Add pane to content pane

      // Code to create the data input panel
      JPanel dataPane = new JPanel();                    // Create the data entry panel
      dataPane.setBorder(BorderFactory.createCompoundBorder(   // Create pane border
                         BorderFactory.createLineBorder(Color.black),
                         BorderFactory.createEmptyBorder(5, 5, 5, 5)));  
      GridBagLayout gbLayout = new GridBagLayout();            // Create the layout
      dataPane.setLayout(gbLayout);                            // Set the pane layout
      GridBagConstraints constraints = new GridBagConstraints();
  
      // Code to create the font choice and add it to the input panel
      JLabel label = new JLabel("Choose a Font");
      constraints.fill = GridBagConstraints.HORIZONTAL;
      constraints.gridwidth = GridBagConstraints.REMAINDER; 
      gbLayout.setConstraints(label, constraints);
      dataPane.add(label);

      // Code to set up font list choice component
      GraphicsEnvironment e = GraphicsEnvironment.getLocalGraphicsEnvironment();
      String[] fontNames = e.getAvailableFontFamilyNames();  // Get the font names

      fontList = new JList(fontNames);                     // Create list of font names
      fontList.setValueIsAdjusting(true);                  // single event selection
      fontList.setSelectionMode(ListSelectionModel.SINGLE_SELECTION); // Choose 1 font
      fontList.setSelectedValue(font.getFamily(),true);
      fontList.addListSelectionListener(this);
      JScrollPane chooseFont = new JScrollPane(fontList);  // Scrollable list
      chooseFont.setMinimumSize(new Dimension(300,100));
 
      // Panel to display font sample
      JPanel display = new JPanel();
      fontDisplay = new JLabel("Sample Size: x X y Y z Z");
      fontDisplay.setPreferredSize(new Dimension(300,100));
      display.add(fontDisplay);

      //Create a split pane with font choice at the top
      // and font display at the bottom
      JSplitPane splitPane = new JSplitPane(JSplitPane.VERTICAL_SPLIT,
                                        true,
                                        chooseFont,
                                        display);
      gbLayout.setConstraints(splitPane, constraints);   // Split pane constraints
      dataPane.add(splitPane);                           // Add to the data pane

      // Set up the size choice using a combobox
      JPanel sizePane = new JPanel();                 // Pane for size choices
      label = new JLabel("Choose point size");        // Prompt for point size
      sizePane.add(label);                            // Add the prompt
      String[] sizeList = { "8", "10", "12", "14", "16",        // Array of sizes
                            "18", "20", "22", "24"};
      chooseSize = new JComboBox(sizeList);                     // Size choice combobox
      chooseSize.setSelectedItem(Integer.toString(fontSize));   // Default selection
      chooseSize.addActionListener(this);                       // Add size listener
      sizePane.add(chooseSize);                                 // Add combobox to pane
      gbLayout.setConstraints(sizePane, constraints);           // Set pane constraints
      dataPane.add(sizePane);                                   // Add the pane

      // Set up style options using radio buttons
      JRadioButton bold = new JRadioButton("Bold", (fontStyle & Font.BOLD) > 0);
      JRadioButton italic = new JRadioButton("Italic", (fontStyle & Font.ITALIC) > 0);
      bold.addItemListener(new StyleListener(Font.BOLD));       // Add button listeners
      italic.addItemListener(new StyleListener(Font.ITALIC));
      JPanel stylePane = new JPanel();                          // Create style pane
      stylePane.add(bold);                                      // Add buttons
      stylePane.add(italic);                                    // to style pane...
      gbLayout.setConstraints(stylePane, constraints);          // Set pane constraints
      dataPane.add(stylePane);                                  // Add the pane
 
      getContentPane().add(dataPane, BorderLayout.CENTER);
      pack();
      setVisible(false);


    }

    JButton createButton(String label)
    {
      JButton button = new JButton(label);                  // Create the button
      button.setPreferredSize(new Dimension(80,20));        // Set the size
      button.addActionListener(this);                       // Listener is the dialog
      return button;                                        // Return the button
    }

    public void actionPerformed(ActionEvent e)
    {
      Object source = e.getSource();                // Get the source of the event
      if(source == ok)                              // Is it the OK button?
      {
        window.setCurrentFont(font);                // Set the selected font
        setVisible(false);                          // Hide the dialog
      }

      else if(source == cancel)                     // If it is the Cancel button
        setVisible(false);                          // just hide the dialog

      else if(source == chooseSize)
      {
        fontSize = Integer.parseInt((String)chooseSize.getSelectedItem());
        font = font.deriveFont((float)fontSize);
        fontDisplay.setFont(font);
        fontDisplay.repaint();
      }
    }

    // List selection listener method
    public void valueChanged(ListSelectionEvent e)
    {
      if(!e.getValueIsAdjusting())
      {
        font = new Font((String)fontList.getSelectedValue(), fontStyle, fontSize);
        fontDisplay.setFont(font);
        fontDisplay.repaint();
      }
    }

    class StyleListener implements ItemListener
    {
      public StyleListener(int style)
      {  
        this.style = style;  
      }
  
      public void itemStateChanged(ItemEvent e)
      {
        if(e.getStateChange()==ItemEvent.SELECTED)   // If style was selected
          fontStyle |= style;                        // turn it on in the font style
        else
          fontStyle &= ~style;                       // otherwise turn it off

        font = font.deriveFont(fontStyle);           // Get a new font
        fontDisplay.setFont(font);                   // Change the label font
        fontDisplay.repaint();                       // repaint
      }    
 
      private int style;                             // Style for this listener
    }

    private SketchFrame window;        // The application window
    private Font font;                 // Currently selected font
    private int fontStyle;             // Font style - Plain,Bold,Italic
    private int fontSize;              // Font point size
    private JButton ok;                // OK button
    private JButton cancel;            // Cancel button
    //private String[] fontNames;        // Font family names
    private JList fontList;            // Font list
    private JComboBox chooseSize;      // Font size options
    private JLabel fontDisplay;        // Font sample


  }