Java JTextComponent Word getWordStart(JTextComponent c, int offs)

Description

Determines the start of a word for the given model location.

License

Open Source License

Parameter

Parameter	Description
c	the editor
offs	the offset in the document >= 0

Return

the location in the model of the word start >= 0

Declaration

public static final int getWordStart(JTextComponent c, int offs) throws BadLocationException 

Method Source Code

//package com.java2s;
/*//from w ww  . j  a v a2 s .  c  o m
 * @(#)Utilities.java   1.40 03/01/23
 *
 * Copyright 2003 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */

import javax.swing.text.*;
import java.text.*;

public class Main {
    /**
     * Determines the start of a word for the given model location.
     * Uses BreakIterator.getWordInstance() to actually get the words.
     * 
     * @param c the editor
     * @param offs the offset in the document >= 0
     * @return the location in the model of the word start >= 0
     * @exception BadLocationException if the offset is out of range
     */
    public static final int getWordStart(JTextComponent c, int offs) throws BadLocationException {
        Document doc = c.getDocument();
        Element line = getParagraphElement(c, offs);
        if (line == null) {
            throw new BadLocationException("No word at " + offs, offs);
        }
        int lineStart = line.getStartOffset();
        int lineEnd = Math.min(line.getEndOffset(), doc.getLength());

        String s = doc.getText(lineStart, lineEnd - lineStart);
        if (s != null && s.length() > 0) {
            BreakIterator words = BreakIterator.getWordInstance(c.getLocale());
            words.setText(s);
            int wordPosition = offs - lineStart;
            if (wordPosition >= words.last()) {
                wordPosition = words.last() - 1;
            }
            words.following(wordPosition);
            offs = lineStart + words.previous();
        }
        return offs;
    }

    /**
     * Determines the element to use for a paragraph/line.
     *
     * @param c the editor
     * @param offs the starting offset in the document >= 0
     * @return the element
     */
    public static final Element getParagraphElement(JTextComponent c, int offs) {
        Document doc = c.getDocument();
        if (doc instanceof StyledDocument) {
            return ((StyledDocument) doc).getParagraphElement(offs);
        }
        Element map = doc.getDefaultRootElement();
        int index = map.getElementIndex(offs);
        Element paragraph = map.getElement(index);
        if ((offs >= paragraph.getStartOffset()) && (offs < paragraph.getEndOffset())) {
            return paragraph;
        }
        return null;
    }
}

Related

1. getWordAtCaret(JTextComponent editor)
2. getWordDimensionAtCaret(JTextComponent editor)
3. getWordDimensionBeforeCaret(JTextComponent editor)
4. getWordEnd(JTextComponent c, int offs)
5. getWordEnd(JTextComponent editor, int iOffset)
6. getWordWrappedTextDimension(JTextComponent textComponent, int width)
7. replaceWordAtCaretNice(JTextComponent editor, String strText)
8. searchInTxComp(JTextComponent src, String word)
9. selectWordAtCaret(JTextComponent editor)