/*
* 06/30/2012
*
* RDocument.java - Document class used by RTextAreas.
*
* This library is distributed under a modified BSD license. See the included
* RSyntaxTextArea.License.txt file for details.
*/
package org.fife.ui.rtextarea;
import javax.swing.text.BadLocationException;
import javax.swing.text.GapContent;
import javax.swing.text.PlainDocument;
/**
* The document implementation used by instances of <code>RTextArea</code>.
*
* @author Robert Futrell
* @version 1.0
*/
public class RDocument extends PlainDocument {
/**
* Constructor.
*/
public RDocument() {
super(new RGapContent());
}
/**
* Returns the character in the document at the specified offset.
*
* @param offset The offset of the character.
* @return The character.
* @throws BadLocationException If the offset is invalid.
*/
public char charAt(int offset) throws BadLocationException {
return ((RGapContent)getContent()).charAt(offset);
}
/**
* Document content that provides fast access to individual characters.
*/
private static class RGapContent extends GapContent {
public char charAt(int offset) throws BadLocationException {
if (offset<0 || offset>=length()) {
throw new BadLocationException("Invalid offset", offset);
}
int g0 = getGapStart();
char[] array = (char[]) getArray();
if (offset<g0) { // below gap
return array[offset];
}
return array[getGapEnd() + offset - g0]; // above gap
}
}
}