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 charAtmay
- * 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); - } -}