import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;
import java.io.FileNotFoundException;
import java.util.ArrayList;
import java.util.Scanner;

import javax.swing.JFrame;
import javax.swing.JTextArea;
import javax.swing.JTextField;

public class AllWordsContainingTheSubstring extends JFrame {

  private static final long serialVersionUID = 1L;

  public static void main(String[] args) { // Construct an instance of this
    // class and show it
    AllWordsContainingTheSubstring aWindow = new AllWordsContainingTheSubstring();
    aWindow.setVisible(true);
  }

  private JTextField substring = new JTextField();

  private JTextArea wordsWithSubstring = new JTextArea();

  private ArrayList<String> allWords;

  public AllWordsContainingTheSubstring() {
    // read all words into the list of words
    getAllWords();

    // Lay out the GUI, initialize the instance variable
    setSize(250, 400);
    setLocation(50, 100);
    setTitle("Show words");
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    Container cp = getContentPane();

    cp.add(substring, BorderLayout.NORTH);
    cp.add(wordsWithSubstring, BorderLayout.CENTER);
    wordsWithSubstring.setEditable(false);
    substring.addActionListener(new TextFieldListener());
  }

  private void getAllWords() {
    allWords = new ArrayList<String>();
    Scanner s = null;
    try {
      s = new Scanner(new File("words.txt"));
    } catch (FileNotFoundException e) {
      System.out.println("words.txt not found");
    }

    while (s.hasNextLine()) {
      allWords.add(s.next());
    }
  }

  private class TextFieldListener implements ActionListener {
    public void actionPerformed(ActionEvent ae) {
      wordsWithSubstring.setText("");
      String search = substring.getText().toLowerCase();
      for (int i = 0; i < allWords.size(); i++) {
        String nextWord = allWords.get(i);
        if (nextWord.indexOf(search) >= 0) {
          wordsWithSubstring.append(nextWord + "\n");
        }
      }
      wordsWithSubstring.validate();
    }
  }
}