@Override
public TextPosition getPreTranslationPosition(TextPosition source) {
// find the most recent change to the offset and add it to the
// position
Offset offset = null;
if (offsetMap.containsKey(source)) { // offset change starts at the specified position
offset = offsetMap.get(source);
} else {
SortedMap<TextPosition, Offset> headMap = offsetMap.headMap(source);
if (headMap.isEmpty()) { // no offset change occurs before the position
offset = new Offset(0, 0);
} else { // offset change strictly precedes the position
offset = headMap.get(headMap.lastKey());
}
}
return offset.forwardOffset(source);
}
