jnumberfield.java

OpenSwing的经典示例

package com.sunking.swing;

import javax.swing.*;
import javax.swing.text.*;
import java.awt.*;
import java.awt.event.*;
import java.io.*;

/**
 * <p>Title: OpenSwing</p>
 * <p>Description: JNumberField 数字格式输入框</p>
 * <p>Copyright: Copyright (c) 2004</p>
 * <p>Company: </p>
 * @author <a href="mailto:[e-mail]">SunKing</a>
 * @version 1.0
 */
public class JNumberField
    extends JTextField
    implements ActionListener, FocusListener, Serializable {
    public JNumberField() {
        this(true);
    }

    public JNumberField(boolean addAction) {
        this(0, 16, addAction);
    }

    public JNumberField(int decLen) {
        this(decLen, true);
    }

    public JNumberField(int decLen, boolean addAction) {
        this(decLen, 16, addAction);
    }

    public JNumberField(int decLen, int maxLen) {
        this(decLen, maxLen, true);
    }

    public JNumberField(int decLen, int maxLen, boolean addAction) {
        setPreferredSize(new Dimension(150, 25));
        setDocument(new NumberDocument(decLen, maxLen));
        super.setHorizontalAlignment(JTextField.RIGHT);
        if (addAction) addActionListener(this);
        addFocusListener(this);
    }

    public JNumberField(int decLen, int maxLen, double minRange,
                        double maxRange,
                        boolean addAction) {
        setPreferredSize(new Dimension(150, 25));
        setDocument(new NumberDocument(decLen, maxLen, minRange, maxRange));
        super.setHorizontalAlignment(JTextField.RIGHT);
        if (addAction) addActionListener(this);
        addFocusListener(this);
    }

    public void actionPerformed(ActionEvent e) {
        transferFocus();
    }

    public void focusGained(FocusEvent e) {
        selectAll();
    }

    public void focusLost(FocusEvent e) {
    }

    public static void main(String[] args) {
//        try {
//            UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
//        }
//        catch (Exception e) {
//        }
        JFrame frame = new JFrame();
//        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setTitle("JNumberField Demo");
        frame.getContentPane().setLayout(new FlowLayout());
        frame.getContentPane().add(new JNumberField(), BorderLayout.CENTER);
        frame.getContentPane().add(new JNumberField(10), BorderLayout.CENTER);
        frame.getContentPane().add(new JNumberField(10, 16),
                                   BorderLayout.CENTER);
        frame.getContentPane().add(new JNumberField(10, 16, -10, 100, false),
                                   BorderLayout.CENTER);
        frame.setSize(400, 320);
        Dimension d = Toolkit.getDefaultToolkit().getScreenSize();
        frame.setLocation( (d.width - frame.getSize().width) / 2,
                          (d.height - frame.getSize().height) / 2);
        frame.setVisible(true);
    }
}

class NumberDocument
    extends PlainDocument {
    int maxLength = 16;
    int decLength = 0;
    double minRange = Double.MIN_VALUE;
    double maxRange = Double.MAX_VALUE;
    public NumberDocument(int decLen, int maxLen) {
        maxLength = maxLen;
        decLength = decLen;
    }

    /**
     * @param decLen int  小数位长度
     * @param maxLen int  最大长度(含小数位)
     * @param minRange double  最小值
     * @param maxRange double  最大值
     */
    public NumberDocument(int decLen, int maxLen, double minRange,
                          double maxRange) {
        this(decLen, maxLen);
        this.minRange = minRange;
        this.maxRange = maxRange;
    }

    public NumberDocument(int decLen) {
        decLength = decLen;
    }

    public NumberDocument() {}

    public void insertString(int offset, String s, AttributeSet a) throws
        BadLocationException {
        int len = getLength();
        String str = getText(0, len);
        int decPos = str.indexOf(".");
        if (
            s.equals("F") || s.equals("f") || s.equals("D") || s.equals("d")
            || (str + s).length() > maxLength
            ||
            (decPos > -1 && offset > decPos &&
             ( (str.substring(decPos + 1)) + s).length() > decLength)
            ||
            (str.trim().equals("0") && !s.substring(0, 1).equals(".") &&
             offset != 0)
            || (s.equals(".") && decLength == 0)
            ||
            (s.indexOf(".") > -1 &&
             s.substring(s.indexOf(".") + 1).length() > decLength)
            ) {
            Toolkit.getDefaultToolkit().beep();
            return;
        }
        try {
            str = str.substring(0, offset) + s + str.substring(offset, len);
            if (!str.equals("-") || (str.equals("-") && minRange <= 0)) {
                double d = Double.parseDouble(str);
                if (d < minRange || d > maxRange)
                    throw new Exception();
            }
        }
        catch (Exception e) {
            Toolkit.getDefaultToolkit().beep();
            return;
        }
        super.insertString(offset, s, a);
    }

}