JScrollPanes

Most of the time you’ll just want to let a JScrollPane do its job, but you can also control which scroll bars are allowed—vertical, horizontal, both, or neither:

//: c14:JScrollPanes.java
// Controlling the scrollbars in a JScrollPane.
// <applet code=JScrollPanes width=300 height=725></applet>
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.border.*;
import com.bruceeckel.swing.*;

public class JScrollPanes extends JApplet {
  private JButton
    b1 = new JButton("Text Area 1"),
    b2 = new JButton("Text Area 2"),
    b3 = new JButton("Replace Text"),
    b4 = new JButton("Insert Text");
  private JTextArea
    t1 = new JTextArea("t1", 1, 20),
    t2 = new JTextArea("t2", 4, 20),
    t3 = new JTextArea("t3", 1, 20),
    t4 = new JTextArea("t4", 10, 10),
    t5 = new JTextArea("t5", 4, 20),
    t6 = new JTextArea("t6", 10, 10);
  private JScrollPane
    sp3 = new JScrollPane(t3,
      JScrollPane.VERTICAL_SCROLLBAR_NEVER,
      JScrollPane.HORIZONTAL_SCROLLBAR_NEVER),
    sp4 = new JScrollPane(t4,
      JScrollPane.VERTICAL_SCROLLBAR_ALWAYS,
      JScrollPane.HORIZONTAL_SCROLLBAR_NEVER),
    sp5 = new JScrollPane(t5,
      JScrollPane.VERTICAL_SCROLLBAR_NEVER,
      JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS),
    sp6 = new JScrollPane(t6,
      JScrollPane.VERTICAL_SCROLLBAR_ALWAYS,
      JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
  class B1L implements ActionListener {
    public void actionPerformed(ActionEvent e) {
      t5.append(t1.getText() + "\n");
    }
  }
  class B2L implements ActionListener {
    public void actionPerformed(ActionEvent e) {
      t2.setText("Inserted by Button 2");
      t2.append(": " + t1.getText());
      t5.append(t2.getText() + "\n");
    }
  }
  class B3L implements ActionListener {
    public void actionPerformed(ActionEvent e) {
      String s = " Replacement ";
      t2.replaceRange(s, 3, 3 + s.length());
    }
  }
  class B4L implements ActionListener {
    public void actionPerformed(ActionEvent e) {
      t2.insert(" Inserted ", 10);
    }
  }
  public void init() {
    Container cp = getContentPane();
    cp.setLayout(new FlowLayout());
    // Create Borders for components:
    Border brd = BorderFactory.createMatteBorder(
      1, 1, 1, 1, Color.BLACK);
    t1.setBorder(brd);
    t2.setBorder(brd);
    sp3.setBorder(brd);
    sp4.setBorder(brd);
    sp5.setBorder(brd);
    sp6.setBorder(brd);
    // Initialize listeners and add components:
    b1.addActionListener(new B1L());
    cp.add(b1);
    cp.add(t1);
    b2.addActionListener(new B2L());
    cp.add(b2);
    cp.add(t2);
    b3.addActionListener(new B3L());
    cp.add(b3);
    b4.addActionListener(new B4L());
    cp.add(b4);
    cp.add(sp3);
    cp.add(sp4);
    cp.add(sp5);
    cp.add(sp6);
  }
  public static void main(String[] args) {
    Console.run(new JScrollPanes(), 300, 725);
  }
} ///:~

Using different arguments in the JScrollPane constructor controls the scrollbars that are available. This example also dresses things up a bit using borders.

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