/**
* 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.conversation;
import org.waveprotocol.wave.model.adt.ObservableSingleton;
import org.waveprotocol.wave.model.adt.docbased.DocumentBasedSingleton;
import org.waveprotocol.wave.model.document.ObservableDocument;
import org.waveprotocol.wave.model.document.util.DefaultDocEventRouter;
import org.waveprotocol.wave.model.document.util.DocEventRouter;
import org.waveprotocol.wave.model.id.IdConstants;
import org.waveprotocol.wave.model.id.IdGenerator;
import org.waveprotocol.wave.model.id.IdUtil;
import org.waveprotocol.wave.model.id.ModernIdSerialiser;
import org.waveprotocol.wave.model.id.WaveId;
import org.waveprotocol.wave.model.id.WaveletId;
import org.waveprotocol.wave.model.util.CollectionUtils;
import org.waveprotocol.wave.model.util.CopyOnWriteSet;
import org.waveprotocol.wave.model.util.IdentityMap;
import org.waveprotocol.wave.model.util.Preconditions;
import org.waveprotocol.wave.model.wave.ObservableWavelet;
import org.waveprotocol.wave.model.wave.WaveViewListener;
import org.waveprotocol.wave.model.wave.Wavelet;
import org.waveprotocol.wave.model.wave.opbased.ObservableWaveView;
import java.util.Collection;
import java.util.Collections;
import java.util.Map;
/**
* A conversation view backed by a wave.
*
* @author anorth@google.com (Alex North)
*/
public class WaveBasedConversationView implements ObservableConversationView, WaveViewListener {
/**
* Wraps a wavelet to provide a conversation, or not, depending
* on whether it has a manifest.
*/
private final class ConversationContainer implements
ObservableSingleton.Listener<DocumentBasedManifest> {
private final ObservableWavelet wavelet;
private final ObservableSingleton<DocumentBasedManifest, Void> manifestContainer;
private WaveletBasedConversation conversation;
ConversationContainer(ObservableWavelet wavelet,
ObservableSingleton<DocumentBasedManifest, Void> manifestContainer) {
this.wavelet = wavelet;
this.manifestContainer = manifestContainer;
}
ObservableWavelet getWavelet() {
return wavelet;
}
WaveletBasedConversation getConversation() {
if (conversation == null) {
if (manifestContainer.hasValue()) {
conversation = WaveletBasedConversation.create(
WaveBasedConversationView.this, wavelet, manifestContainer.get(), idGenerator);
}
}
return conversation;
}
@Override
public void onValueChanged(DocumentBasedManifest oldValue, DocumentBasedManifest newValue) {
if (oldValue != null) {
assert conversation != null;
conversations.remove(wavelet);
conversation.destroy();
triggerOnConversationRemoved(conversation);
conversation = null;
}
if (newValue != null) {
assert conversation == null;
conversation = WaveletBasedConversation.create(WaveBasedConversationView.this, wavelet,
newValue, idGenerator);
conversations.put(wavelet, conversation);
triggerOnConversationAdded(conversation);
}
}
}
/** Id of this group of conversations. */
private final String id;
/** Backing wave view. */
private final ObservableWaveView waveView;
/** Generator for new ids. */
private final IdGenerator idGenerator;
/** A container for every conversational wavelet in view. */
private final IdentityMap<Wavelet, ConversationContainer> containers =
CollectionUtils.createIdentityMap();
/** Conversation adapters keyed by their wavelets. */
private final Map<Wavelet, WaveletBasedConversation> conversations = CollectionUtils.newHashMap();
private final CopyOnWriteSet<Listener> listeners = CopyOnWriteSet.create();
/**
* Creates a conversation view on an wave view.
*/
public static WaveBasedConversationView create(ObservableWaveView waveView,
IdGenerator idGenerator) {
String id = idFor(waveView.getWaveId());
WaveBasedConversationView convView = new WaveBasedConversationView(id, waveView, idGenerator);
waveView.addListener(convView);
return convView;
}
/**
* Computes the conversation view id for a wave.
*/
public static String idFor(WaveId wave) {
return ModernIdSerialiser.INSTANCE.serialiseWaveId(wave);
}
private WaveBasedConversationView(
String id, ObservableWaveView waveView, IdGenerator idGenerator) {
this.id = id;
this.waveView = waveView;
this.idGenerator = idGenerator;
for (ObservableWavelet wavelet : waveView.getWavelets()) {
if (IdUtil.isConversationalId(wavelet.getId())) {
createContainer(wavelet);
}
}
}
@Override
public String getId() {
return id;
}
@Override
public Collection<WaveletBasedConversation> getConversations() {
return Collections.unmodifiableCollection(conversations.values());
}
@Override
public WaveletBasedConversation getConversation(String conversationId) {
return getConversation(WaveletBasedConversation.widFor(conversationId));
}
@Override
public WaveletBasedConversation getRoot() {
ObservableWavelet rootWavelet = waveView.getRoot();
return (rootWavelet != null) ? conversations.get(rootWavelet) : null;
}
@Override
public WaveletBasedConversation createRoot() {
ObservableWavelet rootWavelet = waveView.createRoot();
return createNewConversation(rootWavelet);
}
@Override
public WaveletBasedConversation createConversation() {
ObservableWavelet wavelet;
wavelet = waveView.createWavelet();
return createNewConversation(wavelet);
}
// WaveViewListener.
@Override
public void onWaveletAdded(ObservableWavelet wavelet) {
if (IdUtil.isConversationalId(wavelet.getId())) {
createContainer(wavelet);
}
}
@Override
public void onWaveletRemoved(ObservableWavelet wavelet) {
containers.remove(wavelet);
WaveletBasedConversation conversation = conversations.remove(wavelet);
if (conversation != null) {
triggerOnConversationRemoved(conversation);
}
}
@Override
public void addListener(Listener listener) {
listeners.add(listener);
}
@Override
public void removeListener(Listener listener) {
listeners.remove(listener);
}
/**
* Gets the wave view backing this conversation view.
*/
public ObservableWaveView getWaveView() {
return waveView;
}
/**
* Gets the conversation backed by a wavelet; null if the wavelet is not in
* view or does not have conversation structure.
*/
public WaveletBasedConversation getConversation(WaveletId id) {
if (!IdUtil.isConversationalId(id)) {
Preconditions.illegalArgument("Wavelet id " + id + " is not conversational");
}
ObservableWavelet wavelet = waveView.getWavelet(id);
if (wavelet != null) {
return conversations.get(wavelet);
}
return null;
}
/**
* Creates and stores a conversation container. If the container has a
* conversation then initializes that too.
*/
private ConversationContainer createContainer(ObservableWavelet wavelet) {
ObservableDocument manifestDoc = wavelet.getDocument(IdConstants.MANIFEST_DOCUMENT_ID);
DocEventRouter router = DefaultDocEventRouter.create(manifestDoc);
ObservableSingleton<DocumentBasedManifest, Void> manifestContainer =
DocumentBasedSingleton.create(router, manifestDoc.getDocumentElement(),
DocumentBasedManifest.MANIFEST_TOP_TAG, DocumentBasedManifest.FACTORY);
ConversationContainer container = new ConversationContainer(wavelet, manifestContainer);
manifestContainer.addListener(container);
containers.put(wavelet, container);
WaveletBasedConversation conversation = container.getConversation();
if (conversation != null) {
conversations.put(wavelet, conversation);
triggerOnConversationAdded(conversation);
}
return container;
}
/**
* Creates a new conversation model on a wavelet.
*
* @param wavelet wavelet with which to back the conversation
* @return a conversation
*/
private WaveletBasedConversation createNewConversation(ObservableWavelet wavelet) {
assert IdUtil.isConversationalId(wavelet.getId());
// Add conversation structure to the wavelet, then get the conversation
// which may be constructed in the waiter.
WaveletBasedConversation.makeWaveletConversational(wavelet);
// The container will have created the conversation.
assert conversations.containsKey(wavelet);
return conversations.get(wavelet);
}
private void triggerOnConversationAdded(WaveletBasedConversation conversation) {
for (Listener l : listeners) {
l.onConversationAdded(conversation);
}
}
private void triggerOnConversationRemoved(WaveletBasedConversation conversation) {
for (Listener l : listeners) {
l.onConversationRemoved(conversation);
}
}
}