/**
* 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 com.google.wave.api.data;
import com.google.common.base.Preconditions;
import com.google.wave.api.ElementType;
import com.google.wave.api.Range;
import java.util.Map;
import java.util.Map.Entry;
/**
* A interface encapsulating iterating through a document.
*
* <p>
* At some point we could consider turning this into an actual Iterable/Iterator
* thing
*
*/
public interface DocumentHitIterator {
/**
* @returns the next range yielded by this Iterator or null if we're done.
*/
Range next();
/**
* Notify the iterator that the underlying document has changed; a change with
* size delta has been applied at where.
*/
void shift(int where, int delta);
/**
* Singleshot returns a single range.
*/
class Singleshot implements DocumentHitIterator {
private final Range range;
private boolean called;
public Singleshot(Range range) {
this.called = false;
this.range = range;
}
@Override
public Range next() {
if (called) {
return null;
}
called = true;
return this.range;
}
@Override
public void shift(int where, int delta) {
}
}
/**
* TextMatcher yields all ranges in the document matching the searched for
* string.
*/
class TextMatcher implements DocumentHitIterator {
private final ApiView apiView;
private final String searchFor;
private int from;
private int hitsLeft;
public TextMatcher(ApiView apiView, String searchFor, int maxHits) {
Preconditions.checkNotNull(apiView, "Api view must not be null");
Preconditions.checkNotNull(searchFor, "The string to search for must not be null");
this.apiView = apiView;
this.searchFor = searchFor;
this.from = -1;
this.hitsLeft = maxHits;
}
@Override
public Range next() {
if (hitsLeft == 0) {
return null;
}
hitsLeft--;
String searchIn = apiView.apiContents();
int next = searchIn.indexOf(searchFor, from + 1);
if (next == -1) {
return null;
}
from = next;
return new Range(from, from + searchFor.length());
}
@Override
public void shift(int where, int delta) {
if (from != -1) {
if (where - 1 <= from) {
from += delta;
}
}
}
}
/**
* ElementMatcher yields all ranges in the document matching the searched for
* element type.
*/
class ElementMatcher implements DocumentHitIterator {
private int hitsLeft;
private int index;
private final ApiView apiView;
private final ElementType elementType;
private final Map<String, String> restrictions;
public ElementMatcher(
ApiView apiView, ElementType elementType, Map<String, String> restrictions, int maxRes) {
Preconditions.checkNotNull(apiView, "Api view must not be null");
Preconditions.checkNotNull(elementType, "The type of element to search for must not be null");
Preconditions.checkNotNull(restrictions, "The search restricitions must not be null");
this.elementType = elementType;
this.apiView = apiView;
this.index = -1;
this.hitsLeft = maxRes;
this.restrictions = restrictions;
}
@Override
public Range next() {
if (hitsLeft == 0) {
return null;
}
hitsLeft--;
for (ApiView.ElementInfo elementInfo : apiView.getElements()) {
if (elementInfo.element.getType().equals(elementType) && elementInfo.apiPosition > index) {
boolean allMatched = true;
for (Entry<String, String> entry : restrictions.entrySet()) {
if (!entry.getValue().equals(elementInfo.element.getProperty(entry.getKey()))) {
allMatched = false;
break;
}
}
if (!allMatched) {
continue;
}
index = elementInfo.apiPosition;
return new Range(index, index + 1);
}
}
return null;
}
@Override
public void shift(int where, int delta) {
}
}
}