FontDemo.java

// Modified From: http://www.leepoint.net/notes-java/GUI-appearance/fonts/22fontdemo.html
// File   : gui-appearance/font/fontdemo/FontDemo.java
// Purpose: Demo of how to work with fonts.  This class is primarily 
//          user interface.  The accomanying FontPanel class does the drawing.
// Author : Fred Swartz - 28 Sep 2006 - Placed in public domain.

package fontdemo;

import javax.swing.*;
import javax.swing.border.EmptyBorder;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Vector;

/////////////////////////////////////////////////////////////////////// FontDemo
class FontDemo extends JFrame {
    //=================================================================== fields
    private FontPanel  _displayArea;// Where the sample text is displayed.

    //... The following controls are instance variables because they are
    //    referenced at "runtime" in the listeners.  Alternate solutions:
    //    * Declare them as *final* local variables.
    //    * Obtain them from the Event object passed to the listeners, which
    //      is a good solution when a listener is shared (but not here).
    private JSlider    _sizeSlider; // Sets the font size.
    private JComboBox  _fontCombo;  // For selecting one of the installed fonts.
    private JCheckBox  _antialiasedCB; // To draw with antiliasing on/off.

    //================================================================ constants
    private static final int    INITIAL_SIZE  = 18;
    private static final int    INITIAL_STYLE = Font.PLAIN;
    private static final String INITIAL_STYLENAME = "Font.PLAIN";
    private static final String INITIAL_FONTNAME  = "Monospaced";

    //============================================================== constructor
    public FontDemo() {
        //... Create a FontPanel to display the fonts.
        _displayArea = new FontPanel(INITIAL_FONTNAME, INITIAL_STYLE,
                INITIAL_SIZE, false);

        //... Get all font families
        String[] fontNames = GraphicsEnvironment
                .getLocalGraphicsEnvironment()
                .getAvailableFontFamilyNames();

        //... Make vector of all fonts that can display basic chars.
        //    Vector (not newer ArrayList) is used by JComboBox.
        Vector<String> visFonts = new Vector<String>(fontNames.length);
        for (String fontName : fontNames) {
            Font f = new Font(fontName, Font.PLAIN, 12);
            if (f.canDisplay('a')) {
                //... Display only fonts that have the alphabetic characters.
                visFonts.add(fontName);
            } else {
                //    On my machine there are almost 20 fonts (eg, Wingdings)
                //    that don't display text.
                //System.out.println("No alphabetics in " + fontName);
            }
        }

        _fontCombo = new JComboBox(visFonts);         // JComboBox of fonts
        _fontCombo.setSelectedItem(INITIAL_FONTNAME); // Select initial font
        _fontCombo.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                _displayArea.setFontName((String)_fontCombo.getSelectedItem());
            }
        });

        //... Style: Create radio buttons for the 4 style options.
        JRadioButton stylePlainRB  = new JRadioButton("Font.PLAIN", true);
        JRadioButton styleItalicRB = new JRadioButton("Font.ITALIC", false);
        JRadioButton styleBoldRB   = new JRadioButton("Font.BOLD", false);
        JRadioButton styleItalicBoldRB = new JRadioButton("Font.ITALIC+Font.BOLD"
                , false);

        //... Add the buttons to a button group
        ButtonGroup styleGroup = new ButtonGroup();
        styleGroup.add(stylePlainRB);
        styleGroup.add(styleItalicRB);
        styleGroup.add(styleBoldRB);
        styleGroup.add(styleItalicBoldRB);

        //... Add listeners.
        stylePlainRB.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                _displayArea.setFontStyle(Font.PLAIN);
            }
        });
        styleItalicRB.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                _displayArea.setFontStyle(Font.ITALIC);
            }
        });
        styleBoldRB.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                _displayArea.setFontStyle(Font.BOLD);
            }
        });
        styleItalicBoldRB.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                _displayArea.setFontStyle(Font.ITALIC + Font.BOLD);
            }
        });

        //... Antialiasing checkbox
        _antialiasedCB = new JCheckBox("Antialiased");
        _antialiasedCB.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                _displayArea.setAntialiasing(_antialiasedCB.isSelected());
            }
        });

        //... Create a slider for setting the size value
        _sizeSlider = new JSlider(JSlider.HORIZONTAL, 5, 60, INITIAL_SIZE);
        _sizeSlider.setMajorTickSpacing(10); // sets numbers for big tick marks
        _sizeSlider.setMinorTickSpacing(1);  // smaller tick marks
        _sizeSlider.setPaintTicks(true);     // display the ticks
        _sizeSlider.setPaintLabels(true);    // show the numbers
        _sizeSlider.addChangeListener(new ChangeListener() {
            public void stateChanged(ChangeEvent e) {
                _displayArea.setFontSize(_sizeSlider.getValue());
            }
        });

        //... Controls arranged in BoxLayout.
        //    This is pretty ugly, but I didn't feel like struggling with
        //    GridBagLayout, and didn't want to use any of the superior
        //    external layout managers in this program.
        JPanel controls = new JPanel();
        controls.setLayout(new BoxLayout(controls, BoxLayout.Y_AXIS));

        //... Add components to controls panel.
        addToBox(controls, Component.LEFT_ALIGNMENT
                , new JLabel("Font:"), _fontCombo
                , new JLabel("Size:"), _sizeSlider
                , new JLabel("Style:"), stylePlainRB, styleItalicRB
                , styleBoldRB, styleItalicBoldRB
                , _antialiasedCB
        );

        //... Put display+controls in the content pane.
        JPanel content = new JPanel();
        content.setLayout(new BorderLayout(5, 5));
        content.add(_displayArea, BorderLayout.CENTER);
        content.add(controls, BorderLayout.WEST);
        content.setBorder(new EmptyBorder(12, 12, 12, 12));

        //... Set window characteristics
        setContentPane(content);
        setTitle("Font Demo");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        pack();
    }

    //================================================================= addToBox
    // Utility method to add elements to a BoxLayout container.
    private void addToBox(Container cont, float align, JComponent... comps ) {
        for (JComponent comp : comps) {
            comp.setAlignmentX(align);
            cont.add(comp);
        }
    }

    //===================================================================== main
    public static void main(String[] args) {
        JFrame myWindow = new FontDemo();
        myWindow.setVisible(true);
    }

    //////////////////////////////////////////////////////////////// FontPanel class
    static class FontPanel extends JPanel {
        private String _fontName;
        private int    _fontStyle;
        private int    _fontSize;
        private boolean _antialiased;

        //============================================================== constructor
        public FontPanel(String font, int style, int size, boolean antialiased) {
            this.setPreferredSize(new Dimension(400, 100));
            this.setBackground(Color.white);
            this.setForeground(Color.black);
            _fontName  = font;
            _fontStyle = style;
            _fontSize  = size;
            _antialiased = antialiased;
        }

        //================================================= @Override paintComponent
        @Override public void paintComponent(Graphics g) {
            super.paintComponent(g);        // Paint background.

            Graphics2D g2 = (Graphics2D)g;  // Graphics2 for antialiasing.

            String text = "Font(\""
                    + _fontName + "\", "
                    + fontStyleCodeToFontStyleString(_fontStyle) + ", "
                    + _fontSize + ");\n"
                    + "Chinese: 中文汉字,\n"
                    + "Japanese: 日本語のファイル名,\n"
                    + "Korean: 한국어 파일 이름."
                    ;
            Font f = new Font(_fontName, _fontStyle, _fontSize);
            g2.setFont(f);

            if (_antialiased) {
                g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                        RenderingHints.VALUE_ANTIALIAS_ON);
            }

            //... Find the size of this text so we can center it.
            //FontMetrics fm = g2.getFontMetrics(f);  // metrics for this object
            //Rectangle2D rect = fm.getStringBounds(text, g2); // size of string
            //int textHeight  = (int)(rect.getHeight());
            //int textWidth   = (int)(rect.getWidth());

            //... Center text horizontally and vertically
            int x = 20;//(this.getWidth()  - textWidth)  / 2;
            int y = 20;//(this.getHeight() - textHeight) / 2  + fm.getAscent();

            for (String line: text.split("\n")) {
                g2.drawString(line, x, y += g.getFontMetrics().getHeight());
            }
        }

        //================================================================== SETTERS
        public void setFontName(String fn)  { _fontName = fn;    this.repaint();}
        public void setFontSize(int size)   { _fontSize = size;  this.repaint();}
        public void setFontStyle(int style) {_fontStyle = style; this.repaint();}
        public void setAntialiasing(boolean antialiased) {
            _antialiased = antialiased;
            this.repaint();
        }

        //=========================================== fontStyleCodeToFontStyleString
        // Utility method for converting font codes to name.
        public static String fontStyleCodeToFontStyleString(int styleCode) {
            String styleName;
            switch (styleCode) {
                case Font.PLAIN:            styleName = "Font.PLAIN";       break;
                case Font.ITALIC:           styleName = "Font.ITALIC";      break;
                case Font.BOLD:             styleName = "Font.BOLD";        break;
                case Font.ITALIC+Font.BOLD: styleName = "ITALIC+Font.BOLD"; break;
                default: throw new IllegalArgumentException(
                        "fontStyleCodeToFontStyleString: Unknown font code: " +
                                styleCode);
            }
            return styleName;
        }
    }
}