/*******************************************************************************
* Copyright (c) 2000, 2005 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package net.sourceforge.phpdt.internal.ui.text;
import java.text.CharacterIterator;
//incastrix
//import org.eclipse.jface.text.Assert;
import org.eclipse.core.runtime.Assert;
import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.IDocument;
/**
* An IDocument
based implementation of
* CharacterIterator
and CharSequence
. Note that
* the supplied document is not copied; if the document is modified during the
* lifetime of a DocumentCharacterIterator
, the methods
* returning document content may not always return the same values. Also, if
* accessing the document fails with a {@link BadLocationException}, any of
* CharacterIterator
methods as well as charAt
may
* return {@link CharacterIterator#DONE}.
*
* @since 3.0
*/
public class DocumentCharacterIterator implements CharacterIterator,
CharSequence {
private int fIndex = -1;
private final IDocument fDocument;
private final int fFirst;
private final int fLast;
private void invariant() {
Assert.isTrue(fIndex >= fFirst);
Assert.isTrue(fIndex <= fLast);
}
/**
* Creates an iterator for the entire document.
*
* @param document
* the document backing this iterator
*/
public DocumentCharacterIterator(IDocument document) {
this(document, 0);
}
/**
* Creates an iterator, starting at offset first
.
*
* @param document
* the document backing this iterator
* @param first
* the first character to consider
* @throws IllegalArgumentException
* if the indices are out of bounds
*/
public DocumentCharacterIterator(IDocument document, int first)
throws IllegalArgumentException {
this(document, first, document.getLength());
}
/**
* Creates an iterator for the document contents from first
* (inclusive) to last
(exclusive).
*
* @param document
* the document backing this iterator
* @param first
* the first character to consider
* @param last
* the last character index to consider
* @throws IllegalArgumentException
* if the indices are out of bounds
*/
public DocumentCharacterIterator(IDocument document, int first, int last)
throws IllegalArgumentException {
if (document == null)
throw new NullPointerException();
if (first < 0 || first > last)
throw new IllegalArgumentException();
if (last > document.getLength())
throw new IllegalArgumentException();
fDocument = document;
fFirst = first;
fLast = last;
fIndex = first;
invariant();
}
/*
* @see java.text.CharacterIterator#first()
*/
public char first() {
return setIndex(getBeginIndex());
}
/*
* @see java.text.CharacterIterator#last()
*/
public char last() {
if (fFirst == fLast)
return setIndex(getEndIndex());
else
return setIndex(getEndIndex() - 1);
}
/*
* @see java.text.CharacterIterator#current()
*/
public char current() {
if (fIndex >= fFirst && fIndex < fLast)
try {
return fDocument.getChar(fIndex);
} catch (BadLocationException e) {
// ignore
}
return DONE;
}
/*
* @see java.text.CharacterIterator#next()
*/
public char next() {
return setIndex(Math.min(fIndex + 1, getEndIndex()));
}
/*
* @see java.text.CharacterIterator#previous()
*/
public char previous() {
if (fIndex > getBeginIndex()) {
return setIndex(fIndex - 1);
} else {
return DONE;
}
}
/*
* @see java.text.CharacterIterator#setIndex(int)
*/
public char setIndex(int position) {
if (position >= getBeginIndex() && position <= getEndIndex())
fIndex = position;
else
throw new IllegalArgumentException();
invariant();
return current();
}
/*
* @see java.text.CharacterIterator#getBeginIndex()
*/
public int getBeginIndex() {
return fFirst;
}
/*
* @see java.text.CharacterIterator#getEndIndex()
*/
public int getEndIndex() {
return fLast;
}
/*
* @see java.text.CharacterIterator#getIndex()
*/
public int getIndex() {
return fIndex;
}
/*
* @see java.text.CharacterIterator#clone()
*/
public Object clone() {
try {
return super.clone();
} catch (CloneNotSupportedException e) {
throw new InternalError();
}
}
/*
* @see java.lang.CharSequence#length()
*/
public int length() {
return getEndIndex() - getBeginIndex();
}
/**
* {@inheritDoc}
*
* Note that, if the document is modified concurrently, this method may * return {@link CharacterIterator#DONE} if a {@link BadLocationException} * was thrown when accessing the backing document. *
* * @param index * {@inheritDoc} * @return {@inheritDoc} */ public char charAt(int index) { if (index >= 0 && index < length()) try { return fDocument.getChar(getBeginIndex() + index); } catch (BadLocationException e) { // ignore and return DONE return DONE; } else throw new IndexOutOfBoundsException(); } /* * @see java.lang.CharSequence#subSequence(int, int) */ public CharSequence subSequence(int start, int end) { if (start < 0) throw new IndexOutOfBoundsException(); if (end < start) throw new IndexOutOfBoundsException(); if (end > length()) throw new IndexOutOfBoundsException(); return new DocumentCharacterIterator(fDocument, getBeginIndex() + start, getBeginIndex() + end); } }