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      1 /*
      2  * Copyright (C) 2010 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.database.DataSetObservable;
     20 import android.database.DataSetObserver;
     21 import android.util.Log;
     22 
     23 /**
     24  * Collects all corpus results for a single query.
     25  */
     26 public class Suggestions {
     27     private static final boolean DBG = false;
     28     private static final String TAG = "QSB.Suggestions";
     29 
     30     /** True if {@link Suggestions#close} has been called. */
     31     private boolean mClosed = false;
     32     protected final String mQuery;
     33 
     34     /**
     35      * The observers that want notifications of changes to the published suggestions.
     36      * This object may be accessed on any thread.
     37      */
     38     private final DataSetObservable mDataSetObservable = new DataSetObservable();
     39 
     40     private Source mSource;
     41 
     42     private SourceResult mResult;
     43 
     44     private int mRefCount = 0;
     45 
     46     private boolean mDone = false;
     47 
     48     public Suggestions(String query, Source source) {
     49         mQuery = query;
     50         mSource = source;
     51     }
     52 
     53     public void acquire() {
     54         mRefCount++;
     55     }
     56 
     57     public void release() {
     58         mRefCount--;
     59         if (mRefCount <= 0) {
     60             close();
     61         }
     62     }
     63 
     64     public Source getSource() {
     65         return mSource;
     66     }
     67 
     68     /**
     69      * Marks the suggestions set as complete, regardless of whether all corpora have
     70      * returned.
     71      */
     72     public void done() {
     73         mDone = true;
     74     }
     75 
     76     /**
     77      * Checks whether all sources have reported.
     78      * Must be called on the UI thread, or before this object is seen by the UI thread.
     79      */
     80     public boolean isDone() {
     81         return mDone || mResult != null;
     82     }
     83 
     84     /**
     85      * Adds a list of corpus results. Must be called on the UI thread, or before this
     86      * object is seen by the UI thread.
     87      */
     88     public void addResults(SourceResult result) {
     89         if (isClosed()) {
     90             result.close();
     91             return;
     92         }
     93 
     94         if (DBG) {
     95             Log.d(TAG, "addResults["+ hashCode() + "] source:" +
     96                     result.getSource().getName() + " results:" + result.getCount());
     97         }
     98         if (!mQuery.equals(result.getUserQuery())) {
     99           throw new IllegalArgumentException("Got result for wrong query: "
    100                 + mQuery + " != " + result.getUserQuery());
    101         }
    102         mResult = result;
    103         notifyDataSetChanged();
    104     }
    105 
    106     /**
    107      * Registers an observer that will be notified when the reported results or
    108      * the done status changes.
    109      */
    110     public void registerDataSetObserver(DataSetObserver observer) {
    111         if (mClosed) {
    112             throw new IllegalStateException("registerDataSetObserver() when closed");
    113         }
    114         mDataSetObservable.registerObserver(observer);
    115     }
    116 
    117 
    118     /**
    119      * Unregisters an observer.
    120      */
    121     public void unregisterDataSetObserver(DataSetObserver observer) {
    122         mDataSetObservable.unregisterObserver(observer);
    123     }
    124 
    125     /**
    126      * Calls {@link DataSetObserver#onChanged()} on all observers.
    127      */
    128     protected void notifyDataSetChanged() {
    129         if (DBG) Log.d(TAG, "notifyDataSetChanged()");
    130         mDataSetObservable.notifyChanged();
    131     }
    132 
    133     /**
    134      * Closes all the source results and unregisters all observers.
    135      */
    136     private void close() {
    137         if (DBG) Log.d(TAG, "close() [" + hashCode() + "]");
    138         if (mClosed) {
    139             throw new IllegalStateException("Double close()");
    140         }
    141         mClosed = true;
    142         mDataSetObservable.unregisterAll();
    143         if (mResult != null) {
    144             mResult.close();
    145         }
    146         mResult = null;
    147     }
    148 
    149     public boolean isClosed() {
    150         return mClosed;
    151     }
    152 
    153     @Override
    154     protected void finalize() {
    155         if (!mClosed) {
    156             Log.e(TAG, "LEAK! Finalized without being closed: Suggestions[" + getQuery() + "]");
    157         }
    158     }
    159 
    160     public String getQuery() {
    161         return mQuery;
    162     }
    163 
    164     /**
    165      * Gets the list of corpus results reported so far. Do not modify or hang on to
    166      * the returned iterator.
    167      */
    168     public SourceResult getResult() {
    169         return mResult;
    170     }
    171 
    172     public SourceResult getWebResult() {
    173         return mResult;
    174     }
    175 
    176     /**
    177      * Gets the number of source results.
    178      * Must be called on the UI thread, or before this object is seen by the UI thread.
    179      */
    180     public int getResultCount() {
    181         if (isClosed()) {
    182             throw new IllegalStateException("Called getSourceCount() when closed.");
    183         }
    184         return mResult == null ? 0 : mResult.getCount();
    185     }
    186 
    187     @Override
    188     public String toString() {
    189         return "Suggestions@" + hashCode() + "{source=" + mSource
    190                 + ",getResultCount()=" + getResultCount() + "}";
    191     }
    192 
    193 }
    194