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      1 /*
      2  * Copyright (C) 2009 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.quicksearchbox;
     18 
     19 import android.os.Handler;
     20 import android.util.Log;
     21 
     22 import com.android.quicksearchbox.util.BatchingNamedTaskExecutor;
     23 import com.android.quicksearchbox.util.Consumer;
     24 import com.android.quicksearchbox.util.NamedTaskExecutor;
     25 import com.android.quicksearchbox.util.NoOpConsumer;
     26 
     27 /**
     28  * Suggestions provider implementation.
     29  *
     30  * The provider will only handle a single query at a time. If a new query comes
     31  * in, the old one is cancelled.
     32  */
     33 public class SuggestionsProviderImpl implements SuggestionsProvider {
     34 
     35     private static final boolean DBG = false;
     36     private static final String TAG = "QSB.SuggestionsProviderImpl";
     37 
     38     private final Config mConfig;
     39 
     40     private final NamedTaskExecutor mQueryExecutor;
     41 
     42     private final Handler mPublishThread;
     43 
     44     private final Logger mLogger;
     45 
     46     public SuggestionsProviderImpl(Config config,
     47             NamedTaskExecutor queryExecutor,
     48             Handler publishThread,
     49             Logger logger) {
     50         mConfig = config;
     51         mQueryExecutor = queryExecutor;
     52         mPublishThread = publishThread;
     53         mLogger = logger;
     54     }
     55 
     56     @Override
     57     public void close() {
     58     }
     59 
     60     @Override
     61     public Suggestions getSuggestions(String query, Source sourceToQuery) {
     62         if (DBG) Log.d(TAG, "getSuggestions(" + query + ")");
     63         final Suggestions suggestions = new Suggestions(query, sourceToQuery);
     64         Log.i(TAG, "chars:" + query.length() + ",source:" + sourceToQuery);
     65 
     66         Consumer<SourceResult> receiver;
     67         if (shouldDisplayResults(query)) {
     68             receiver = new SuggestionCursorReceiver(suggestions);
     69         } else {
     70             receiver = new NoOpConsumer<SourceResult>();
     71             suggestions.done();
     72         }
     73 
     74         int maxResults = mConfig.getMaxResultsPerSource();
     75         QueryTask.startQuery(query, maxResults, sourceToQuery, mQueryExecutor,
     76                 mPublishThread, receiver);
     77 
     78         return suggestions;
     79     }
     80 
     81     private boolean shouldDisplayResults(String query) {
     82         if (query.length() == 0 && !mConfig.showSuggestionsForZeroQuery()) {
     83             // Note that even though we don't display such results, it's
     84             // useful to run the query itself because it warms up the network
     85             // connection.
     86             return false;
     87         }
     88         return true;
     89     }
     90 
     91 
     92     private class SuggestionCursorReceiver implements Consumer<SourceResult> {
     93         private final Suggestions mSuggestions;
     94 
     95         public SuggestionCursorReceiver(Suggestions suggestions) {
     96             mSuggestions = suggestions;
     97         }
     98 
     99         @Override
    100         public boolean consume(SourceResult cursor) {
    101             if (DBG) {
    102                 Log.d(TAG, "SuggestionCursorReceiver.consume(" + cursor + ") corpus=" +
    103                         cursor.getSource() + " count = " + cursor.getCount());
    104             }
    105             // publish immediately
    106             if (DBG) Log.d(TAG, "Publishing results");
    107             mSuggestions.addResults(cursor);
    108             if (cursor != null && mLogger != null) {
    109                 mLogger.logLatency(cursor);
    110             }
    111             return true;
    112         }
    113 
    114     }
    115 }
    116