| /* |
| * Copyright (C) 2015 The Android Open Source Project |
| * |
| * 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.android.tv.recommendation; |
| |
| import java.util.List; |
| |
| public class FavoriteChannelEvaluator extends Recommender.Evaluator { |
| private static final long MIN_WATCH_PERIOD_MS = 1000 * 60 * 60 * 24; // 1 day |
| // When there is no watch history, use the current time as a default value. |
| private long mEarliestWatchStartTimeMs = System.currentTimeMillis(); |
| |
| @Override |
| protected void onChannelRecordListChanged(List<ChannelRecord> channelRecords) { |
| for (ChannelRecord cr : channelRecords) { |
| WatchedProgram[] watchedPrograms = cr.getWatchHistory(); |
| if (watchedPrograms.length > 0 |
| && mEarliestWatchStartTimeMs > watchedPrograms[0].getWatchStartTimeMs()) { |
| mEarliestWatchStartTimeMs = watchedPrograms[0].getWatchStartTimeMs(); |
| } |
| } |
| } |
| |
| @Override |
| public double evaluateChannel(long channelId) { |
| ChannelRecord cr = getRecommender().getChannelRecord(channelId); |
| if (cr == null) { |
| return NOT_RECOMMENDED; |
| } |
| |
| if (cr.getTotalWatchDurationMs() == 0) { |
| return NOT_RECOMMENDED; |
| } |
| |
| long watchPeriodMs = System.currentTimeMillis() - mEarliestWatchStartTimeMs; |
| return (double) cr.getTotalWatchDurationMs() / Math.max(watchPeriodMs, MIN_WATCH_PERIOD_MS); |
| } |
| } |