/**
* 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.box.common;
import com.google.common.base.Function;
import com.google.common.collect.Lists;
import org.waveprotocol.wave.model.document.operation.AnnotationBoundaryMap;
import org.waveprotocol.wave.model.document.operation.Attributes;
import org.waveprotocol.wave.model.document.operation.AttributesUpdate;
import org.waveprotocol.wave.model.document.operation.DocInitializationCursor;
import org.waveprotocol.wave.model.document.operation.DocOp;
import org.waveprotocol.wave.model.document.operation.DocOpCursor;
import org.waveprotocol.wave.model.document.operation.impl.InitializationCursorAdapter;
import org.waveprotocol.wave.model.wave.data.ReadableBlipData;
import org.waveprotocol.wave.model.wave.data.ReadableWaveletData;
import org.waveprotocol.wave.model.wave.data.WaveletData;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Set;
/**
* Utility methods for rendering snippets.
*
* @author anorth@google.com (Alex North)
*/
public final class Snippets {
private final static Function<StringBuilder, Void> DEFAULT_LINE_MODIFIER =
new Function<StringBuilder, Void>() {
@Override
public Void apply(StringBuilder resultBuilder) {
resultBuilder.append(" ");
return null;
}
};
public static final int DIGEST_SNIPPET_LENGTH = 140;
/**
* Concatenates all of the text for the given documents in
* {@link WaveletData}.
*
* @param wavelet the wavelet for which to concatenate the documents.
* @return A String containing the characters from all documents.
*/
public static String collateTextForWavelet(ReadableWaveletData wavelet) {
List<ReadableBlipData> documents = new ArrayList<ReadableBlipData>();
for (String documentId : wavelet.getDocumentIds()) {
documents.add(wavelet.getDocument(documentId));
}
return collateTextForDocuments(documents);
}
/**
* Concatenates all of the text of the specified blips into a single String.
*
* @param documents the documents to concatenate.
* @return A String containing the characters from all documents.
*/
public static String collateTextForDocuments(Iterable<? extends ReadableBlipData> documents) {
ArrayList<DocOp> docOps = new ArrayList<DocOp>();
for (ReadableBlipData blipData : documents) {
docOps.add(blipData.getContent().asOperation());
}
return collateTextForOps(docOps);
}
/**
* Concatenates all of the text of the specified docops into a single String.
*
* @param documentops the document operations to concatenate.
* @param func the function that will be applied on result when
* DocumentConstants.LINE event is be encountered during parsing.
* @return A String containing the characters from the operations.
*/
public static String collateTextForOps(Iterable<? extends DocOp> documentops,
final Function<StringBuilder, Void> func) {
final StringBuilder resultBuilder = new StringBuilder();
for (DocOp docOp : documentops) {
docOp.apply(InitializationCursorAdapter.adapt(new DocOpCursor() {
@Override
public void characters(String s) {
resultBuilder.append(s);
}
@Override
public void annotationBoundary(AnnotationBoundaryMap map) {
}
@Override
public void elementStart(String type, Attributes attrs) {
if (type.equals(DocumentConstants.LINE)) {
func.apply(resultBuilder);
}
}
@Override
public void elementEnd() {
}
@Override
public void retain(int itemCount) {
}
@Override
public void deleteCharacters(String chars) {
}
@Override
public void deleteElementStart(String type, Attributes attrs) {
}
@Override
public void deleteElementEnd() {
}
@Override
public void replaceAttributes(Attributes oldAttrs, Attributes newAttrs) {
}
@Override
public void updateAttributes(AttributesUpdate attrUpdate) {
}
}));
}
return resultBuilder.toString().trim();
}
/**
* Concatenates all of the text of the specified docops into a single String.
*
* @param documentops the document operations to concatenate.
* @return A String containing the characters from the operations.
*/
public static String collateTextForOps(Iterable<? extends DocOp> documentops) {
return collateTextForOps(documentops, DEFAULT_LINE_MODIFIER);
}
/**
* Returns a snippet or null.
*/
public static String renderSnippet(final ReadableWaveletData wavelet,
final int maxSnippetLength) {
final StringBuilder sb = new StringBuilder();
Set<String> docsIds = wavelet.getDocumentIds();
long newestLmt = -1;
ReadableBlipData newestBlip = null;
for (String docId : docsIds) {
ReadableBlipData blip = wavelet.getDocument(docId);
long currentLmt = blip.getLastModifiedTime();
if (currentLmt > newestLmt) {
newestLmt = currentLmt;
newestBlip = blip;
}
}
if (newestBlip == null) {
// Render whatever data we have and hope its good enough
sb.append(collateTextForWavelet(wavelet));
} else {
DocOp docOp = newestBlip.getContent().asOperation();
sb.append(collateTextForOps(Lists.newArrayList(docOp)));
sb.append(" ");
docOp.apply(InitializationCursorAdapter.adapt(new DocInitializationCursor() {
@Override
public void annotationBoundary(AnnotationBoundaryMap map) {
}
@Override
public void characters(String chars) {
// No chars in the conversation manifest
}
@Override
public void elementEnd() {
}
@Override
public void elementStart(String type, Attributes attrs) {
if (sb.length() >= maxSnippetLength) {
return;
}
if (DocumentConstants.BLIP.equals(type)) {
String blipId = attrs.get(DocumentConstants.BLIP_ID);
if (blipId != null) {
ReadableBlipData document = wavelet.getDocument(blipId);
if (document == null) {
// We see this when a blip has been deleted
return;
}
sb.append(collateTextForDocuments(Arrays.asList(document)));
sb.append(" ");
}
}
}
}));
}
if (sb.length() > maxSnippetLength) {
return sb.substring(0, maxSnippetLength);
}
return sb.toString();
}
private Snippets() {
}
}