private void indentHeading(AuthorElement heading) throws Exception {
Matcher matcher = HEADING_PATTERN.matcher(heading.getLocalName());
matcher.matches();
int lvl = Integer.parseInt(matcher.group(1));
if (lvl == 6) throw new AuthorOperationException("Operation not permitted on h6.");
AuthorElement level = (AuthorElement) heading.getParent();
assert (isDtbElement("level" + lvl, level));
controller.renameElement(heading, "h" + (lvl + 1));
AuthorElement nextSubLevel =
xpath.getElement("following-sibling::level" + (lvl + 1), heading, controller);
controller.surroundInFragment(
dtbElement("level" + (lvl + 1)),
heading.getStartOffset(),
(nextSubLevel != null) ? nextSubLevel.getStartOffset() - 1 : level.getEndOffset() - 1);
AuthorElement previousLevel =
xpath.getElement(
"preceding-sibling::*[not(normalize-space(string(.))='')][1][self::level" + lvl + "]",
level,
controller);
if (previousLevel != null) {
int insertAt = previousLevel.getEndOffset();
controller.insertFragment(
insertAt,
controller.createDocumentFragment(level.getStartOffset() + 1, level.getEndOffset() - 1));
controller.deleteNode(level);
level = getElementAtOffset(insertAt + 1, controller);
}
editor.setCaretPosition(
xpath.getElement("descendant::h" + (lvl + 1), level, controller).getStartOffset() + 1);
}
protected void doOperation() throws Exception {
AuthorElement element = getElementAtOffset(getSelectionStart(editor), controller);
Matcher matcher = HEADING_PATTERN.matcher(element.getLocalName());
if (!isDtbElement(element) || !matcher.matches())
throw new AuthorOperationException("Operation only permitted on heading elements.");
indentHeading(element);
}