1 /* 2 * Copyright (C) 2015 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.android.tv.recommendation; 18 19 import java.util.List; 20 21 public class FavoriteChannelEvaluator extends Recommender.Evaluator { 22 private static final long MIN_WATCH_PERIOD_MS = 1000 * 60 * 60 * 24; // 1 day 23 // When there is no watch history, use the current time as a default value. 24 private long mEarliestWatchStartTimeMs = System.currentTimeMillis(); 25 26 @Override 27 protected void onChannelRecordListChanged(List<ChannelRecord> channelRecords) { 28 for (ChannelRecord cr : channelRecords) { 29 WatchedProgram[] watchedPrograms = cr.getWatchHistory(); 30 if (watchedPrograms.length > 0 31 && mEarliestWatchStartTimeMs > watchedPrograms[0].getWatchStartTimeMs()) { 32 mEarliestWatchStartTimeMs = watchedPrograms[0].getWatchStartTimeMs(); 33 } 34 } 35 } 36 37 @Override 38 public double evaluateChannel(long channelId) { 39 ChannelRecord cr = getRecommender().getChannelRecord(channelId); 40 if (cr == null) { 41 return NOT_RECOMMENDED; 42 } 43 44 if (cr.getTotalWatchDurationMs() == 0) { 45 return NOT_RECOMMENDED; 46 } 47 48 long watchPeriodMs = System.currentTimeMillis() - mEarliestWatchStartTimeMs; 49 return (double) cr.getTotalWatchDurationMs() / 50 Math.max(watchPeriodMs, MIN_WATCH_PERIOD_MS); 51 } 52 } 53
