AutoCompleteDocument.java

/**
 * Copyright 1999-2009 The Pegadi Team
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.pegadi.swing;

import org.pegadi.util.AutoCompleteCatalog;

import javax.swing.*;
import javax.swing.text.AttributeSet;
import javax.swing.text.BadLocationException;
import javax.swing.text.PlainDocument;

/**
 * Use this document with a JTextField to add the autocomplete feature to it.
 * @author Ingar Saltvik
 */

public class AutoCompleteDocument extends PlainDocument {

    private JTextField tf; //I don't see an easy way to avoid this
    //model-view coupling.

    private AutoCompleteCatalog cat;

    /**
     * Default constructor.
     * @param tf The JTextField to which this document belongs. Yes, it is an ugly model-view hack.
     * @param filename The file which the autocompletionstexts will be read from.
     */

    public AutoCompleteDocument(JTextField tf, String filename) {
        super();
        this.tf = tf;
        cat = new AutoCompleteCatalog(filename);
    }

    /**
     * @see javax.swing.text.Document#insertString(int, String, AttributeSet)
     */
    public void insertString(int offset, String str, AttributeSet a)
        throws BadLocationException {

        String precedingText = getText(0,getLength());

        String completionText = cat.getCompletionText(precedingText + str);

        if(completionText.length()>0 && str.length()==1 && tf.getCaret().getMark()==getLength()) {
            super.insertString(offset,completionText,a);
            tf.moveCaretPosition(Math.min(getLength(),offset + str.length()));
            tf.getCaret().moveDot(offset+str.length());
        } else {
            super.insertString(offset,str,a);
        }

        //I'm not sure how to pass the selection info to the
        //JTextField without doing it in the Document

    }
    /**
     * @see org.pegadi.util.AutoCompleteCatalog
     */

    public void save(String newEntry) {
        cat.save(newEntry);
    }

    public static void main(String[] args) {
        JFrame f = new JFrame();
        final JTextField t = new JTextField(15);
        final AutoCompleteDocument doc = new AutoCompleteDocument(t, args[0]);
        t.addKeyListener(new java.awt.event.KeyAdapter() {
                public void keyPressed(java.awt.event.KeyEvent e) {
                    if (e.getKeyCode() == java.awt.event.KeyEvent.VK_ENTER)
                        doc.save(t.getText());
                }
            });
        t.setDocument(doc);
        f.getContentPane().add(t);
        f.pack();
        f.setVisible(true);
    }
}