/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.waveprotocol.wave.model.document.operation;
/**
* Do not rely on this. This is just a temporary location modifier being used
* for transitional purposes. The proper way will be to use annotations.
*
*/
public class LocationModifier implements DocOpCursor {
private int mutatingLocation;
private int scanPoint = 0;
/**
* @param location The location to transform
*/
public LocationModifier(int location) {
this.mutatingLocation = location;
}
@Override
public void retain(int itemCount) {
scanPoint += itemCount;
}
@Override
public void characters(String characters) {
insert(characters.length());
}
@Override
public void elementStart(String type, Attributes attributes) {
insert(1);
}
@Override
public void elementEnd() {
insert(1);
}
@Override
public void deleteCharacters(String chars) {
delete(chars.length());
}
@Override
public void deleteElementStart(String type, Attributes attributes) {
delete(1);
}
@Override
public void deleteElementEnd() {
delete(1);
}
private void insert(int size) {
if (scanPoint < mutatingLocation) {
mutatingLocation += size;
scanPoint += size;
}
}
private void delete(int size) {
if (scanPoint <= mutatingLocation) {
mutatingLocation = Math.max(scanPoint, mutatingLocation - size);
}
}
@Override
public void replaceAttributes(Attributes oldAttributes, Attributes newAttributes) {
retain(1);
}
@Override
public void updateAttributes(AttributesUpdate attributesUpdate) {
retain(1);
}
@Override
public void annotationBoundary(AnnotationBoundaryMap m) {}
/**
* @param op
* @param location
* @return location transformed against mutation
*/
public static int transformLocation(DocOp op, int location) {
LocationModifier modifier = new LocationModifier(location);
op.apply(modifier);
return modifier.mutatingLocation;
}
}