/**
* Copyright 2009 Google Inc.
*
* Licensed 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.automaton;
import org.waveprotocol.wave.model.document.operation.Attributes;
import org.waveprotocol.wave.model.document.operation.impl.AnnotationMap;
/**
* The query methods that DocOpAutomaton needs.
*/
public interface AutomatonDocument {
/**
* If pos is at an element start, return that element's tag. Else
* return null.
*/
String elementStartingAt(int pos);
/**
* If pos is at an element start, return that element's attributes. Else
* return null.
*/
Attributes attributesAt(int pos);
/**
* If pos is at an element end, return that element's tag. Else return
* null.
*/
String elementEndingAt(int pos);
// -1 if no char (i.e., element start or end) at that position
int charAt(int pos);
// depth = 0 means enclosing element, depth = 1 means its parent,
// etc. null return value means nesting is not that deep.
String nthEnclosingElementTag(int insertionPoint, int depth);
// number of chars after insertionPoint before the next element
// start or end or document end.
int remainingCharactersInElement(int insertionPoint);
AnnotationMap annotationsAt(int pos);
String getAnnotation(int pos, String key);
int length();
/**
* Finds the first item within a range with the specified key having a value
* other than fromValue.
*
* @param start start of the range to search
* @param end end of the range to search
* @param key key to search for
* @param fromValue value to check for change from
* @return the location of the first change, or -1 if there is no change
*/
int firstAnnotationChange(int start, int end, String key, String fromValue);
}