}
if (document instanceof IDocumentExtension4) {
IDocumentExtension4 extension = (IDocumentExtension4) document;
DocumentRewriteSessionType type = (selection.y == 0 || selection.y > MAX_SMALL_FORMAT_LENGTH) ? DocumentRewriteSessionType.UNRESTRICTED : DocumentRewriteSessionType.UNRESTRICTED_SMALL;
rewriteSession = (extension.getActiveRewriteSession() != null) ? null : extension.startRewriteSession(type);
}
else {
setRedraw(false);
}