Creating the Font Dialog Box

The FontClass.java file allows you to create the Font dialog box for the Text Editor application. End users can use this dialog box to specify the font type, size , and style to change the font of the text file.

Listing 6-4 shows the contents of the FontClass.java file:

Listing 6-4: The FontClass.java File

 /* Imports javax.swing package classes. */ import javax.swing.JPanel; import javax.swing.JButton; import javax.swing.JLabel; import javax.swing.JTextField; import javax.swing.JList; import javax.swing.JScrollPane; import javax.swing.JDialog; import javax.swing.BorderFactory; /* Imports java.awt package classes. */ import java.awt.GraphicsEnvironment; import java.awt.GridBagConstraints; import java.awt.GridBagLayout; import java.awt.FlowLayout; import java.awt.Font; /* Imports javax.swing.event package classes. */ import javax.swing.event.ListSelectionListener; import javax.swing.event.ListSelectionEvent; /* class FontClass - This class creates a Font dialog box that enables the  end user to change the font, size, and type of the text. Fields:     fontLabel - Contains the content of Font label.    sizeLabel - Contains the content of Size label.    typeLabel - Contains the content of Type label.    previewLabel - Contains the content of preview.    label - Contains the preview contents.    fontText - Contains the selected font name.    typeText - Contains the selected font type name.    sizeText - Contains the selected font size name.    fontScroll - Contains the Font list.    typeScroll - Contains the Type list.    sizeScroll - Contains the Size list.    fontList - Contains all the available font.    typeList - Contains all the available types of font style.    sizeList - Contains all the available font size.    ok - Creates an OK button.    cancel - Creates a cancel button. Methods:    getOK() - This method returns the OK button object    getCancel() - This method returns the Cancel button object    valueChanged() - This method is invoked when an end user select the item from the List box.    font() - This method returns the font */ public class FontClass extends JDialog implements ListSelectionListener {    /* Declares the objects of the JPanel class. */    JPanel pan1;    JPanel pan2;    JPanel pan3;    /* Declares the objects of the JLabel class. */    JLabel fontLabel;    JLabel sizeLabel;    JLabel typeLabel;    JLabel previewLabel;    /* Declares the objects of the JTextField class. */    JTextField label;    JTextField fontText;    JTextField sizeText;    JTextField typeText;    /* Declares the objects of the JScrollPane class. */    JScrollPane fontScroll;    JScrollPane typeScroll;    JScrollPane sizeScroll;    /* Declares the objects of the JList class. */    JList fontList;    JList sizeList;    JList typeList;    /* Declares the objects of the JButton class. */    JButton ok;    JButton cancel;    GridBagLayout gbl;    GridBagConstraints gbc;    /* Defines the default constructor. */    public FontClass()    {       /* Sets the title of the Font dialog. */       setTitle("Font Dialog");       /* Sets the size of Font dialog. */       setSize(300, 400);       /* Sets resizable button to false. */       setResizable(false);       /* Initializes the object of the GridBagLayout class. */       gbl = new GridBagLayout();       /* Sets the Layout. */       getContentPane().setLayout(gbl);       /* Creates an object of GridBagConstraints class. */       gbc = new GridBagConstraints();       /*        Initializes the Font label object and add it to the 1, 1, 1, 1 positions with WEST alignment.        */       gbc.gridx = 1;        gbc.gridy = 1;       gbc.gridwidth = 1;       gbc.gridheight = 1;       gbc.anchor = GridBagConstraints.WEST;       fontLabel = new JLabel("Fonts: ");       getContentPane().add(fontLabel, gbc);       /*        Initializes the Size label object and adds it to the 2, 1, 1, 1 positions with WEST alignment.        */        gbc.gridx = 2;        gbc.gridy = 1;       gbc.gridwidth = 1;       gbc.gridheight = 1;       gbc.anchor = GridBagConstraints.WEST;       sizeLabel = new JLabel("Sizes: ");       getContentPane().add(sizeLabel, gbc);       /*        Initializes the Types label object and adds it to the 3, 1, 1, 1 positions with WEST alignment.        */       gbc.gridx = 3;        gbc.gridy = 1;       gbc.gridwidth = 1;       gbc.gridheight = 1;       gbc.anchor = GridBagConstraints.WEST;       typeLabel = new JLabel("Types: ");       getContentPane().add(typeLabel, gbc);       /*        Initializes the Font text field object and adds it to the 1, 2, 1, 1 positions with WEST alignment.        */       gbc.gridx = 1;        gbc.gridy = 2;       gbc.gridwidth = 1;       gbc.gridheight = 1;       gbc.anchor = GridBagConstraints.WEST;       fontText = new JTextField("Arial", 12);       getContentPane().add(fontText, gbc);       /*        Initializes the Size text field object and adds it to the 2, 2, 1, 1 positions with WEST alignment.        */       gbc.gridx = 2;        gbc.gridy = 2;       gbc.gridwidth = 1;       gbc.gridheight = 1;       gbc.anchor = GridBagConstraints.WEST;       sizeText = new JTextField("8", 4);       getContentPane().add(sizeText, gbc);       /*        Initializes the Types text field object and adds it to the 3, 2, 1, 1 positions with WEST alignment.        */       gbc.gridx = 3;        gbc.gridy = 2;       gbc.gridwidth = 1;       gbc.gridheight = 1;       gbc.anchor = GridBagConstraints.WEST;       typeText = new JTextField("Regular", 6);       getContentPane().add(typeText, gbc);       /*        Initializes the Font list object and add it to the Font scroll pane object.        Adds this scroll pane object to 1, 3, 1, 1 positions with WEST alignment        */       gbc.gridx = 1;        gbc.gridy = 3;       gbc.gridwidth = 1;       gbc.gridheight = 1;       gbc.anchor = GridBagConstraints.WEST;       String[] fonts = GraphicsEnvironment.getLocalGraphicsEnvironment().getAvailableFontFamilyNames();       fontList = new JList(fonts);       fontList.setFixedCellWidth(110);        fontList.addListSelectionListener(this);       fontList.setSelectedIndex(0);       fontScroll = new JScrollPane(fontList);       getContentPane().add(fontScroll, gbc);       /*        Initializes the Size list object and add it to the Size scroll pane object.        Adds this scroll pane object to 2, 3, 1, 1 positions with WEST alignment        */       gbc.gridx = 2;        gbc.gridy = 3;       gbc.gridwidth = 1;       gbc.gridheight = 1;       gbc.anchor = GridBagConstraints.WEST;       String[] sizes = {"8","10","12","14","16","18","20","24","28","32","48","72"};       sizeList = new JList(sizes);       sizeList.setSelectedIndex(0);       sizeList.setFixedCellWidth(20);        sizeList.addListSelectionListener(this);       sizeScroll = new JScrollPane(sizeList);        getContentPane().add(sizeScroll, gbc);       /*        Initializes the Types list object and adds it to the Types scroll pane object.        Next, adds this scroll pane object to 3, 3, 1, 1 positions with WEST alignment        */       gbc.gridx = 3;        gbc.gridy = 3;       gbc.gridwidth = 1;       gbc.gridheight = 1;       gbc.anchor = GridBagConstraints.WEST;       String[] types = {"Regular", "Bold", "Italic", "Bold Italic"};       typeList = new JList(types);       typeList.setFixedCellWidth(60);        typeList.addListSelectionListener(this);       typeList.setSelectedIndex(0);       typeScroll = new JScrollPane(typeList);        getContentPane().add(typeScroll, gbc);       /*        Initializes the preview label and adds it to 1,4,3,1 positions with CENTER alignment.        */       gbc.gridx = 1;        gbc.gridy = 4;       gbc.gridwidth = 3;       gbc.gridheight = 1;       gbc.anchor = GridBagConstraints.CENTER;       pan1 = new JPanel();       pan1.setLayout(new FlowLayout());       previewLabel = new JLabel("Preview:");       pan1.add(previewLabel);       getContentPane().add(pan1, gbc);       /*        Initializes the preview text field and adds it to 1,5,3,1 positions with CENTER alignment.        */       gbc.gridx = 1;        gbc.gridy = 5;       gbc.gridwidth = 3;       gbc.gridheight = 1;       gbc.anchor = GridBagConstraints.CENTER;       pan2 = new JPanel();       pan2.setLayout(new FlowLayout());       label = new JTextField("AaBaCcDdeEfFgGhHjJ", 15);       label.setEditable(false);       label.setBorder(BorderFactory.createEtchedBorder());       label.setFont(new Font("Arial",Font.PLAIN,20));       pan2.add(label);       getContentPane().add(pan2, gbc);       /*        Initializes the OK and Cancel button and adds these two buttons to the panel.        Sets layout of the panel to FlowLayout. Now add this panel to the 1, 6, 4, 1        positions with CENTER alignment.        */       gbc.gridx = 1;        gbc.gridy = 6;       gbc.gridwidth = 3;       gbc.gridheight = 1;       gbc.anchor = GridBagConstraints.CENTER;       pan3 = new JPanel();       pan3.setLayout(new FlowLayout());       ok = new JButton("OK");       cancel = new JButton("Cancel");       pan3.add(ok);       pan3.add(cancel);       getContentPane().add(pan3, gbc);    }    /*    valueChanged() - This method is called when the user selects any menu item from the menu bar.    Parameters: lse - a ListSelectionEvent object containing details of the event.    Return Value: NA    */    public void valueChanged(ListSelectionEvent lse)    {       try       {          /*           This section is executed, when end user selects the item from Font list.           */          if(lse.getSource() == fontList)          {             Font f1 = new Font(String.valueOf(fontList.getSelectedValue()),typeList.getSelectedIndex(),             Integer.parseInt(String.valueOf(sizeList.getSelectedValue())));             fontText.setText(String.valueOf(fontList.getSelectedValue()));             label.setFont(f1);          }          /*           This section is executed, when end user selects the item from Size list.           */          else if(lse.getSource() == sizeList)          {             Font f2 = new Font(String.valueOf(fontList.getSelectedValue()),typeList.getSelectedIndex(),             Integer.parseInt(String.valueOf(sizeList.getSelectedValue())));             sizeText.setText(String.valueOf(sizeList.getSelectedValue()));             label.setFont(f2);          }          /*           This section is executed, when end user selects the item from Type list.           */          else if(lse.getSource() == typeList)          {             Font f2 = new Font(String.valueOf(fontList.getSelectedValue()),typeList.getSelectedIndex(),             Integer.parseInt(String.valueOf(sizeList.getSelectedValue())));             typeText.setText(String.valueOf(typeList.getSelectedValue()));             label.setFont(f2);          }       }       catch(Exception nfe){}    }    /*    font() - This method is set the font of the file text.    Parameters: NA    Return Value: font    */    public Font font()    {       /* Creates an object of the Font class. */       Font font = new Font(String.valueOf(fontList.getSelectedValue()), typeList.getSelectedIndex(),       Integer.parseInt(String.valueOf(sizeList.getSelectedValue())));       /* Returns the font object */       return font;    }    /*    getOk() method - This method is invoked when end user click the OK button of the Font dialog box    parameter - NA    return value - ok    */    public JButton getOk()    {       return ok;    }    /*    getCancel() method - This method is invoked when end user click the Cancel button of the Font dialog box.    parameter - NA    return value - cancel    */    public JButton getCancel()    {       return cancel;    } } 

 

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In the above code, the FontClass() constructor creates the Font dialog box, as shown in Figure 6-4:

Figure 6-4: The Font Dialog Box

When an end user selects any item from the list box of the Font dialog box, the Font class invokes the valueChanged() method. This method acts as an event listener and activates the appropriate method to set the font of the preview label.

The FontClass defines two methods, getOK() and getCancel(), to perform the OK and Cancel operations. These methods return the object of the Button class.

When an end user clicks the OK button in the Font dialog box, the actionPerformed() method is invoked in the ActionPerform class. This method sets the visibility of the Font dialog box to false and changes the font of the file text, based on the selected font type, size, and style.

If an end user clicks the Cancel button in the Font dialog box, the actionPerformed() method is invoked in the ActionPerform class. This method sets the visibility of the Font dialog box to false and closes the Font dialog box.