finddialog.java

这是一个用JAVA编写的记事本的原码。功能和WINDOWS自带基本一样。

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

public class FindDialog extends JDialog  
{ 
    private Container pane; 
    private JTextArea text; 
    private JFrame owner; 
    private JLabel findLabel; 
    private JTextField findText; 
    private JButton findNext, cancel; 
    private JCheckBox upperLowerCase; 
    private JPanel upDownPanel; 
    private JRadioButton upButton, downButton; 
    private ButtonGroup upDownGroup; 
    private StringBuffer findString; 
     
    public FindDialog( JFrame frame, JTextArea textArea, StringBuffer string ) 
    { 
        super( frame, "查找" ); 
        owner = frame; 
        text = textArea; 
        findString = string; 
        pane = getContentPane(); 
        pane.setLayout( null ); 
        findLabel = new JLabel( "查找内容：" ); 
        findLabel.setBounds(18, 20, 70, 21); 
        pane.add( findLabel ); 
        findText = new JTextField( findString.toString() ); 
        findText.setBounds(94, 20, 147, 21); 
        findText.getDocument().addDocumentListener( 
            new DocumentListener() 
            { 
                public void changedUpdate( DocumentEvent e ) 
                { 
                } 
                 
                public void insertUpdate( DocumentEvent e ) 
                { 
                    findNext.setEnabled( true ); 
                } 
                 
                public void removeUpdate( DocumentEvent e ) 
                { 
                    if( findText.getText().equals( "" ) )  
                        findNext.setEnabled( false ); 
                } 
            } 
        ); 
        pane.add( findText ); 
        findNext = new JButton( "查找下一个" ); 
        findNext.setBounds(262, 20, 107, 21); 
        findNext.setEnabled( !findText.getText().equals( "" ) ); 
        findNext.addActionListener( 
            new ActionListener() 
            { 
                public void actionPerformed( ActionEvent e ) 
                { 
                    findString.delete( 0, findString.length() ); 
                    findString.append( findText.getText() ); 
                    find(); 
                } 
            } 
        ); 
        pane.add( findNext ); 
        upperLowerCase = new JCheckBox( "区分大小写" ); 
        upperLowerCase.setBounds(18, 82, 93, 21); 
        pane.add( upperLowerCase ); 
        upDownPanel = new JPanel(); 
        upDownPanel.setBounds(118, 48, 122, 55); 
        TitledBorder tb = new TitledBorder( BorderFactory.createLineBorder( Color.BLACK ), "方向" ); 
        upDownPanel.setBorder( tb ); 
        upButton = new JRadioButton( "向上" ); 
        upDownPanel.add( upButton ); 
        downButton = new JRadioButton( "向下" ); 
        downButton.setSelected( true ); 
        upDownPanel.add( downButton ); 
        upDownGroup = new ButtonGroup(); 
        upDownGroup.add( upButton ); 
        upDownGroup.add( downButton ); 
        pane.add( upDownPanel ); 
        cancel = new JButton( "取消" ); 
        cancel.setBounds(262, 57, 107, 21); 
        cancel.addActionListener( 
            new ActionListener() 
            { 
                public void actionPerformed( ActionEvent e ) 
                { 
                    dispose(); 
                } 
            } 
        ); 
        pane.add( cancel ); 
        setSize( 395, 147 ); 
        int x = ( int )( owner.getLocation().getX() + owner.getWidth() / 2 -200 ); 
        x = ( x > 624 ? 624 : x ); 
        x = ( x < 0 ? 0 : x ); 
        int y = ( int )( owner.getLocation().getY() + owner.getHeight() / 2 - 75 ); 
        y = ( y > 620 ? 620 : y ); 
        y = ( y < 0 ? 0 : y ); 
        setLocation( x, y ); 
        setResizable( false ); 
    } 
     
    public void find() 
    { 
        int x = text.getCaretPosition(); 
        if( text.getSelectedText() != null && 
            text.getSelectedText().toLowerCase().equals( findString.toString().toLowerCase() ) 
                && upButton.isSelected() )  
                x--; 
        String tString = text.getText(); 
        String fString = findString.toString(); 
        if( ! upperLowerCase.isSelected() ) 
        { 
            tString = tString.toLowerCase(); 
            fString = fString.toLowerCase(); 
        } 
        if( downButton.isSelected() ) 
        { 
            x = tString.indexOf( fString, x ); 
        } 
        else 
        { 
            String str = tString.substring( 0, x ); 
            x = str.lastIndexOf( fString, x - fString.length() ); 
        } 
        if( x == -1 ) 
        { 
            JOptionPane.showMessageDialog( owner, "没找到 \"" + fString + "\"" ); 
        } 
        else 
        { 
            text.select( x, x + fString.length() ); 
        } 
    } 
}