textfields.java

来自「thinking in java 书中源码 第四版」· Java 代码 · 共 83 行

//: gui/TextFields.java
// Text fields and Java events.
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.text.*;
import java.awt.*;
import java.awt.event.*;
import static net.mindview.util.SwingConsole.*;

public class TextFields extends JFrame {
  private JButton
    b1 = new JButton("Get Text"),
    b2 = new JButton("Set Text");
  private JTextField
    t1 = new JTextField(30),
    t2 = new JTextField(30),
    t3 = new JTextField(30);
  private String s = "";
  private UpperCaseDocument ucd = new UpperCaseDocument();
  public TextFields() {
    t1.setDocument(ucd);
    ucd.addDocumentListener(new T1());
    b1.addActionListener(new B1());
    b2.addActionListener(new B2());
    t1.addActionListener(new T1A());
    setLayout(new FlowLayout());
    add(b1);
    add(b2);
    add(t1);
    add(t2);
    add(t3);
  }
  class T1 implements DocumentListener {
    public void changedUpdate(DocumentEvent e) {}
    public void insertUpdate(DocumentEvent e) {
      t2.setText(t1.getText());
      t3.setText("Text: "+ t1.getText());
    }
    public void removeUpdate(DocumentEvent e) {
      t2.setText(t1.getText());
    }
  }
  class T1A implements ActionListener {
    private int count = 0;
    public void actionPerformed(ActionEvent e) {
      t3.setText("t1 Action Event " + count++);
    }
  }
  class B1 implements ActionListener {
    public void actionPerformed(ActionEvent e) {
      if(t1.getSelectedText() == null)
        s = t1.getText();
      else
        s = t1.getSelectedText();
      t1.setEditable(true);
    }
  }
  class B2 implements ActionListener {
    public void actionPerformed(ActionEvent e) {
      ucd.setUpperCase(false);
      t1.setText("Inserted by Button 2: " + s);
      ucd.setUpperCase(true);
      t1.setEditable(false);
    }
  }
  public static void main(String[] args) {
    run(new TextFields(), 375, 200);
  }
}

class UpperCaseDocument extends PlainDocument {
  private boolean upperCase = true;
  public void setUpperCase(boolean flag) {
    upperCase = flag;
  }
  public void
  insertString(int offset, String str, AttributeSet attSet)
  throws BadLocationException {
    if(upperCase) str = str.toUpperCase();
    super.insertString(offset, str, attSet);
  }
} ///:~