org.waveprotocol.examples.robots.echoey.Echoey.java Source code

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Here is the source code for org.waveprotocol.examples.robots.echoey.Echoey.java

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/**
 * 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.examples.robots.echoey;

import com.google.common.base.Preconditions;
import com.google.common.cache.CacheBuilder;
import com.google.wave.api.AbstractRobot;
import com.google.wave.api.Annotation;
import com.google.wave.api.Blip;
import com.google.wave.api.Context;
import com.google.wave.api.Wavelet;
import com.google.wave.api.event.AnnotatedTextChangedEvent;
import com.google.wave.api.event.DocumentChangedEvent;
import com.google.wave.api.event.WaveletBlipCreatedEvent;

import java.util.List;
import java.util.Map;
import java.util.concurrent.TimeUnit;

/**
 * Robot that echoes the changes to a wave.
 *
 * @author ljvderijk@google.com (Lennard de Rijk)
 */
public class Echoey extends AbstractRobot {

    /** Annotation for text by Echoey */
    private static final String ECHOEY_ANNOTATION = "www.waveprotocol.org/echoey";

    private final Map<String, String> shadowBlipMap;

    public Echoey() {
        shadowBlipMap = CacheBuilder.newBuilder().expireAfterWrite(1, TimeUnit.HOURS).<String, String>build()
                .asMap();
    }

    @Override
    protected String getRobotName() {
        return "Echoey";
    }

    @Override
    protected String getRobotProfilePageUrl() {
        return "http://www.waveprotocol.org/";
    }

    @Capability(contexts = { Context.SELF, Context.SIBLINGS })
    @Override
    public void onWaveletBlipCreated(WaveletBlipCreatedEvent event) {
        Blip blip = event.getNewBlip();
        if (!isShadowBlip(blip)) {
            createShadowBlip(blip);
        }
    }

    @Capability(contexts = { Context.SELF, Context.SIBLINGS })
    @Override
    public void onDocumentChanged(DocumentChangedEvent event) {
        Blip blip = event.getBlip();
        if (!isShadowBlip(blip)) {
            createOrUpdateShadowBlip(blip);
        }
    }

    @Capability(contexts = { Context.SELF, Context.SIBLINGS })
    @Override
    public void onAnnotatedTextChanged(AnnotatedTextChangedEvent event) {
        Blip blip = event.getBlip();
        if (!isShadowBlip(blip)) {
            createOrUpdateShadowBlip(blip);
        }
    }

    /**
     * Creates a new shadow blip.
     *
     *  Note that this method will not know the id of the new blip since the
     * server will generate it.
     *
     * @param blip the blip to create a new shadow blip for.
     */
    private void createShadowBlip(Blip blip) {
        Blip newBlip = blip.continueThread();
        newBlip.all().replace(blip.getContent());
        newBlip.all().annotate(ECHOEY_ANNOTATION, blip.getBlipId());
    }

    /**
     * Creates or updates an existing shadow blip that should shadow the given
     * blip.
     *
     * @param blipToShadow the blip that should be shadowed.
     */
    private void createOrUpdateShadowBlip(Blip blipToShadow) {
        Wavelet wavelet = blipToShadow.getWavelet();
        String blipId = blipToShadow.getBlipId();
        if (shadowBlipMap.containsKey(blipId)) {
            Blip shadowBlip = wavelet.getBlip(shadowBlipMap.get(blipId));
            updateShadowBlip(shadowBlip, blipToShadow);
        } else {
            updateShadowMap(wavelet);

            if (!shadowBlipMap.containsKey(blipId)) {
                createShadowBlip(blipToShadow);
            } else {
                // Update existing shadow Blip
                Blip shadowBlip = wavelet.getBlip(shadowBlipMap.get(blipId));
                updateShadowBlip(shadowBlip, blipToShadow);
            }
        }
    }

    /**
     * Updates an existing shadow blip.
     *
     * @param shadowBlip the blip that is shadowing.
     * @param blipToShadow the blip being shadowed.
     */
    private void updateShadowBlip(Blip shadowBlip, Blip blipToShadow) {
        Preconditions.checkNotNull(shadowBlip, "Shadow blip can't be null");
        Preconditions.checkNotNull(blipToShadow, "Blip to shadow can't be null");
        shadowBlip.all().replace(blipToShadow.getContent());

        for (Annotation annotation : blipToShadow.getAnnotations()) {
            if (annotation.getName().equals(ECHOEY_ANNOTATION)) {
                continue;
            }
            shadowBlip.range(annotation.getRange().getStart(), annotation.getRange().getEnd())
                    .annotate(annotation.getName(), annotation.getValue());
        }
        shadowBlip.all().annotate(ECHOEY_ANNOTATION, blipToShadow.getBlipId());

        shadowBlipMap.put(blipToShadow.getBlipId(), shadowBlip.getBlipId());
    }

    /**
     * Updates the shadow map for a given wavelet.
     */
    private void updateShadowMap(Wavelet wavelet) {
        for (Blip blip : wavelet.getBlips().values()) {
            if (isShadowBlip(blip)) {
                String shadowBlipId = blip.getBlipId();
                if (!shadowBlipMap.containsValue(shadowBlipId)) {
                    String originalBlipId = blip.getAnnotations().get(ECHOEY_ANNOTATION).get(0).getValue();
                    shadowBlipMap.put(originalBlipId, shadowBlipId);
                }
            }
        }
    }

    /**
     * Return true if the given blip is a blip in which Echoey has written.
     */
    private boolean isShadowBlip(Blip blip) {
        List<Annotation> annotations = blip.getAnnotations().get(ECHOEY_ANNOTATION);
        return annotations != null && !annotations.isEmpty();
    }
}