Java: TextFieldDemo

/*
 * TextFieldDemo.java requires one additional file:
 * content.txt
 */

package demo;

import java.awt.Color;
import java.awt.event.ActionEvent;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import javax.swing.*;
import javax.swing.text.*;
import javax.swing.event.*;
import javax.swing.GroupLayout.*;

public class TextFieldDemo extends JFrame implements DocumentListener {

  private JTextField entry;
  private JLabel jLabel1;
  private JScrollPane jScrollPane1;
  private JLabel status;
  private JTextArea textArea;

  final static Color HILIT_COLOR = Color.LIGHT_GRAY;
  final static Color ERROR_COLOR = Color.PINK;
  final static String CANCEL_ACTION = "cancel-search";

  final Color entryBg;
  final Highlighter hilit;
  final Highlighter.HighlightPainter painter;


  public TextFieldDemo() {
    initComponents();

    InputStream in = getClass().getResourceAsStream("content.txt");
    try {
      textArea.read(new InputStreamReader(in), null);
    } catch (IOException e) {
      e.printStackTrace();
    }

    hilit = new DefaultHighlighter();
    painter = new DefaultHighlighter.DefaultHighlightPainter(HILIT_COLOR);
    textArea.setHighlighter(hilit);

    entryBg = entry.getBackground();
    entry.getDocument().addDocumentListener(this);

    InputMap im = entry.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW);
    ActionMap am = entry.getActionMap();
    im.put(KeyStroke.getKeyStroke("ESCAPE"), CANCEL_ACTION);
    am.put(CANCEL_ACTION, new CancelAction());
  }

  /**
   * This method is called from within the constructor to
   * initialize the form.
   */

  private void initComponents() {
    entry = new JTextField();
    textArea = new JTextArea();
    status = new JLabel();
    jLabel1 = new JLabel();

    setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
    setTitle("TextFieldDemo");

    textArea.setColumns(20);
    textArea.setLineWrap(true);
    textArea.setRows(5);
    textArea.setWrapStyleWord(true);
    textArea.setEditable(false);
    jScrollPane1 = new JScrollPane(textArea);

    jLabel1.setText("Enter text to search:");

    GroupLayout layout = new GroupLayout(getContentPane());
    getContentPane().setLayout(layout);

    //Create a parallel group for the horizontal axis
    ParallelGroup hGroup = layout.createParallelGroup(GroupLayout.Alignment.LEADING);

    //Create a sequential and a parallel groups
    SequentialGroup h1 = layout.createSequentialGroup();
    ParallelGroup h2 = layout.createParallelGroup(GroupLayout.Alignment.TRAILING);

    //Add a container gap to the sequential group h1
    h1.addContainerGap();

    //Add a scroll pane and a label to the parallel group h2
    h2.addComponent(jScrollPane1, GroupLayout.Alignment.LEADING, GroupLayout.DEFAULT_SIZE, 450, Short.MAX_VALUE);
    h2.addComponent(status, GroupLayout.Alignment.LEADING, GroupLayout.DEFAULT_SIZE, 450, Short.MAX_VALUE);

    //Create a sequential group h3
    SequentialGroup h3 = layout.createSequentialGroup();
    h3.addComponent(jLabel1);
    h3.addPreferredGap(LayoutStyle.ComponentPlacement.RELATED);
    h3.addComponent(entry, GroupLayout.DEFAULT_SIZE, 321, Short.MAX_VALUE);

    //Add the group h3 to the group h2
    h2.addGroup(h3);
    //Add the group h2 to the group h1
    h1.addGroup(h2);

    h1.addContainerGap();

    //Add the group h1 to the hGroup
    hGroup.addGroup(GroupLayout.Alignment.TRAILING, h1);
    //Create the horizontal group
    layout.setHorizontalGroup(hGroup);


    //Create a parallel group for the vertical axis
    ParallelGroup vGroup = layout.createParallelGroup(GroupLayout.Alignment.LEADING);
    //Create a sequential group v1
    SequentialGroup v1 = layout.createSequentialGroup();
    //Add a container gap to the sequential group v1
    v1.addContainerGap();
    //Create a parallel group v2
    ParallelGroup v2 = layout.createParallelGroup(GroupLayout.Alignment.BASELINE);
    v2.addComponent(jLabel1);
    v2.addComponent(entry, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE);
    //Add the group v2 tp the group v1
    v1.addGroup(v2);
    v1.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED);
    v1.addComponent(jScrollPane1, GroupLayout.DEFAULT_SIZE, 233, Short.MAX_VALUE);
    v1.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED);
    v1.addComponent(status);
    v1.addContainerGap();

    //Add the group v1 to the group vGroup
    vGroup.addGroup(v1);
    //Create the vertical group
    layout.setVerticalGroup(vGroup);
    pack();
  }

  public void search() {
    hilit.removeAllHighlights();

    String s = entry.getText();
    if (s.length() <= 0) {
      message("Nothing to search");
      return;
    }

    String content = textArea.getText();
    int index = content.indexOf(s, 0);
    if (index >= 0) { // match found
      try {
        int end = index + s.length();
        hilit.addHighlight(index, end, painter);
        textArea.setCaretPosition(end);
        entry.setBackground(entryBg);
        message("'" + s + "' found. Press ESC to end search");
      } catch (BadLocationException e) {
        e.printStackTrace();
      }
    } else {
      entry.setBackground(ERROR_COLOR);
      message("'" + s + "' not found. Press ESC to start a new search");
    }
  }

  void message(String msg) {
    status.setText(msg);
  }

  // DocumentListener methods

  public void insertUpdate(DocumentEvent ev) {
    search();
  }

  public void removeUpdate(DocumentEvent ev) {
    search();
  }

  public void changedUpdate(DocumentEvent ev) {
  }

  class CancelAction extends AbstractAction {
    public void actionPerformed(ActionEvent ev) {
      hilit.removeAllHighlights();
      entry.setText("");
      entry.setBackground(entryBg);
    }
  }


  public static void main(String args[]) {
    //Schedule a job for the event dispatch thread:
    //creating and showing this application's GUI.
    SwingUtilities.invokeLater(new Runnable() {
      public void run() {
        //Turn off metal's use of bold fonts
        UIManager.put("swing.boldMetal", Boolean.FALSE);
        new TextFieldDemo().setVisible(true);
      }
    });
  }
}