/*
 * Copyright (c) 2006 Sun Microsystems, Inc. All Rights Reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * -Redistribution of source code must retain the above copyright notice, this
 *  list of conditions and the following disclaimer.
 *
 * -Redistribution in binary form must reproduce the above copyright notice,
 *  this list of conditions and the following disclaimer in the documentation
 *  and/or other materials provided with the distribution.
 *
 * Neither the name of Sun Microsystems, Inc. or the names of contributors may
 * be used to endorse or promote products derived from this software without
 * specific prior written permission.
 *
 * This software is provided "AS IS," without a warranty of any kind. ALL
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING
 * ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
 * OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN MIDROSYSTEMS, INC. ("SUN")
 * AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE
 * AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
 * DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR ANY LOST
 * REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL,
 * INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY
 * OF LIABILITY, ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE,
 * EVEN IF SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
 *
 * You acknowledge that this software is not designed, licensed or intended
 * for use in the design, construction, operation or maintenance of any
 * nuclear facility.
 */
import java.util.List;
import javax.swing.JTextField;
import javax.swing.text.*;

public class Java2sAutoTextField extends JTextField {
  class AutoDocument extends PlainDocument {

    public void replace(int i, int j, String s, AttributeSet attributeset)
        throws BadLocationException {
      super.remove(i, j);
      insertString(i, s, attributeset);
    }

    public void insertString(int i, String s, AttributeSet attributeset)
        throws BadLocationException {
      if (s == null || "".equals(s))
        return;
      String s1 = getText(0, i);
      String s2 = getMatch(s1 + s);
      int j = (i + s.length()) - 1;
      if (isStrict && s2 == null) {
        s2 = getMatch(s1);
        j--;
      } else if (!isStrict && s2 == null) {
        super.insertString(i, s, attributeset);
        return;
      }
      if (autoComboBox != null && s2 != null)
        autoComboBox.setSelectedValue(s2);
      super.remove(0, getLength());
      super.insertString(0, s2, attributeset);
      setSelectionStart(j + 1);
      setSelectionEnd(getLength());
    }

    public void remove(int i, int j) throws BadLocationException {
      int k = getSelectionStart();
      if (k > 0)
        k--;
      String s = getMatch(getText(0, k));
      if (!isStrict && s == null) {
        super.remove(i, j);
      } else {
        super.remove(0, getLength());
        super.insertString(0, s, null);
      }
      if (autoComboBox != null && s != null)
        autoComboBox.setSelectedValue(s);
      try {
        setSelectionStart(k);
        setSelectionEnd(getLength());
      } catch (Exception exception) {
      }
    }

  }

  public Java2sAutoTextField(List list) {
    isCaseSensitive = false;
    isStrict = false;
    autoComboBox = null;
    if (list == null) {
      throw new IllegalArgumentException("values can not be null");
    } else {
      dataList = list;
      init();
      return;
    }
  }

  Java2sAutoTextField(List list, Java2sAutoComboBox b) {
    isCaseSensitive = false;
    isStrict = false;
    autoComboBox = null;
    if (list == null) {
      throw new IllegalArgumentException("values can not be null");
    } else {
      dataList = list;
      autoComboBox = b;
      init();
      return;
    }
  }

  private void init() {
    setDocument(new AutoDocument());
    if (isStrict && dataList.size() > 0)
      setText(dataList.get(0).toString());
  }

  private String getMatch(String s) {
    for (int i = 0; i < dataList.size(); i++) {
      String s1 = dataList.get(i).toString();
      if (s1 != null) {
        if (!isCaseSensitive
            && s1.toLowerCase().startsWith(s.toLowerCase()))
          return s1;
        if (isCaseSensitive && s1.startsWith(s))
          return s1;
      }
    }

    return null;
  }

  public void replaceSelection(String s) {
    AutoDocument _lb = (AutoDocument) getDocument();
    if (_lb != null)
      try {
        int i = Math.min(getCaret().getDot(), getCaret().getMark());
        int j = Math.max(getCaret().getDot(), getCaret().getMark());
        _lb.replace(i, j - i, s, null);
      } catch (Exception exception) {
      }
  }

  public boolean isCaseSensitive() {
    return isCaseSensitive;
  }

  public void setCaseSensitive(boolean flag) {
    isCaseSensitive = flag;
  }

  public boolean isStrict() {
    return isStrict;
  }

  public void setStrict(boolean flag) {
    isStrict = flag;
  }

  public List getDataList() {
    return dataList;
  }

  public void setDataList(List list) {
    if (list == null) {
      throw new IllegalArgumentException("values can not be null");
    } else {
      dataList = list;
      return;
    }
  }

  private List dataList;

  private boolean isCaseSensitive;

  private boolean isStrict;

  private Java2sAutoComboBox autoComboBox;
}

This is  a modification of the Sun tutorial code that initializes the text editor to accept words that are not part of the auto-complete list. In the terms of the implementation, it is referred to as "not strict".

Java2sAutoTextField  : non-strict default setting

java

Java