jfinddialog.java

本程序不仅实现了记事本基本的功能

/*
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 * and open the template in the editor.
 */
package jnotepad;

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

/**
 *
 * @author Administrator
 */
class JFindDialog extends JDialog implements ActionListener {

    public JFindDialog(Frame owner, JTextArea area) {
        super(owner, "查找", false);
        this.area = area;
        //this.setLayout(new FlowLayout());
        this.setLayout(null);
        label.setBounds(10, 10, 80, 25);
        txtfld.setBounds(90, 10, 250, 25);
        upper_lower.setBounds(10, 70, 140, 25);
        okbn.setBounds(345, 10, 120, 25);
        cancelbn.setBounds(345, 50, 120, 25);
        radiopanel.setBounds(150,45,150,90);

        group.add(up);
        group.add(down);

        radiopanel.add(up);
        radiopanel.add(down);
        radiopanel.setBorder(new TitledBorder("方向"));

        this.add(label);
        this.add(txtfld);
        this.add(okbn);
        this.add(upper_lower);
        this.add(radiopanel);
        this.add(cancelbn);
        this.addWindowListener(new WindowAdapter() {

            @Override
            public void windowClosing(WindowEvent e) {
                JFindDialog.this.dispose();//!!!!!!!!
            }
        });
        //txtfld.addTextListener();

        txtfld.addKeyListener(new KeyAdapter() {

            public void keyReleased(KeyEvent e) {
                String str = txtfld.getText();
                if(!str.equals(""))
                    okbn.setEnabled(true);
                else
                    okbn.setEnabled(false);
            }
        });
        okbn.addActionListener(this);
        okbn.setSelected(true);
        okbn.setEnabled(false);
        cancelbn.addActionListener(this);
        up.addActionListener(this);
        down.addActionListener(this);
        down.setSelected(true);
        upper_lower.addActionListener(this);
        this.setResizable(false);
        this.setBounds(500, 300, 500, 180);
        this.setVisible(true);
    }

    public void actionPerformed(ActionEvent e) {
        if (e.getSource() == okbn) {
            findNext();
        }
        if (e.getSource() == cancelbn) {
            JFindDialog.this.dispose();
        }
        if (e.getSource() == up) {
            finddown = false;
        }
        if (e.getSource() == down) {
            finddown = true;
        }
        if (e.getSource() == upper_lower) {
            if (teller) {
                teller = false;
            } else {
                teller = true;
            }
        }
    }

    private void findNext()
    {
        String obj = txtfld.getText();
            String all = area.getText();
            int len = obj.length();
            int end = all.length();
            int start = area.getSelectionEnd();//从光标位置开始查找字符串
            if (finddown) {
                nUp = false;
                for (; start <= end - len; start++) {
                    if (teller) {
                        if (all.substring(start, start + len).equals(obj)) {//若找到查找字符串
                            area.setSelectionStart(start); //选中并显示字符串
                            area.setSelectionEnd(start + len);
                            return; //退出方法
                        }
                    } else if ( all.substring(start, start + len).toLowerCase(). equals (obj.toLowerCase())) {//若找到查找字符串
                        area.setSelectionStart(start); //选中并显示字符串
                        area.setSelectionEnd(start + len);
                        return; //退出方法
                    }
                }
            } else {
                //area.setSelectionEnd(start-);
                if (nUp) {
                    start -= len;
                }
                for (; start >= len; start--) {
                    if (teller) {
                        if (all.substring(start - len, start).equals(obj)) {//若找到查找字符串
                            area.setSelectionStart(start - len); //选中并显示字符串
                            area.setSelectionEnd(start);
                            nUp = true;
                            return; //退出方法
                        }
                    } else if ( all.substring(start - len, start).toLowerCase(). equals(obj.toLowerCase())) {//若找到查找字符串
                        area.setSelectionStart(start - len); //选中并显示字符串
                        area.setSelectionEnd(start);
                        nUp = true;
                        return; //退出方法
                    }
                }
            }
            JOptionPane.showMessageDialog(this, "          找不到“" + obj +
                    "”", "记事本", JOptionPane.INFORMATION_MESSAGE);
    }
    private JLabel label = new JLabel("查找内容(N):");
    private JTextField txtfld = new JTextField(24);
    private JButton okbn = new JButton("查找下一个(F)");
    private JButton cancelbn = new JButton("取   消");
    private JRadioButton up = new JRadioButton("向上(U)");
    private JRadioButton down = new JRadioButton("向下(D)");
    private JCheckBox upper_lower = new JCheckBox("是否区分大小写(C)");
    private ButtonGroup group = new ButtonGroup();
    private JPanel radiopanel = new JPanel();
    JTextArea area = new JTextArea();
    boolean finddown = true;
    boolean nUp = false;
    boolean teller = false;
}