OpenSearchSearchEngine.java revision 2d8ab9b3b334dbbc1a66ae48b424f4c10f547831
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 */
16package com.android.browser.search;
17
18import com.android.browser.R;
19
20import org.apache.http.HttpResponse;
21import org.apache.http.client.HttpClient;
22import org.apache.http.client.methods.HttpGet;
23import org.apache.http.params.HttpParams;
24import org.apache.http.util.EntityUtils;
25import org.json.JSONArray;
26import org.json.JSONException;
27
28import android.app.SearchManager;
29import android.content.Context;
30import android.content.Intent;
31import android.database.AbstractCursor;
32import android.database.Cursor;
33import android.net.ConnectivityManager;
34import android.net.NetworkInfo;
35import android.net.Uri;
36import android.net.http.AndroidHttpClient;
37import android.os.Bundle;
38import android.provider.Browser;
39import android.text.TextUtils;
40import android.util.Log;
41
42import java.io.IOException;
43
44/**
45 * Provides search suggestions, if any, for a given web search provider.
46 */
47public class OpenSearchSearchEngine implements SearchEngine {
48
49    private static final String TAG = "OpenSearchSearchEngine";
50
51    private static final String USER_AGENT = "Android/1.0";
52    private static final int HTTP_TIMEOUT_MS = 1000;
53
54    // TODO: this should be defined somewhere
55    private static final String HTTP_TIMEOUT = "http.connection-manager.timeout";
56
57    // Indices of the columns in the below arrays.
58    private static final int COLUMN_INDEX_ID = 0;
59    private static final int COLUMN_INDEX_QUERY = 1;
60    private static final int COLUMN_INDEX_ICON = 2;
61    private static final int COLUMN_INDEX_TEXT_1 = 3;
62    private static final int COLUMN_INDEX_TEXT_2 = 4;
63
64    // The suggestion columns used. If you are adding a new entry to these arrays make sure to
65    // update the list of indices declared above.
66    private static final String[] COLUMNS = new String[] {
67        "_id",
68        SearchManager.SUGGEST_COLUMN_QUERY,
69        SearchManager.SUGGEST_COLUMN_ICON_1,
70        SearchManager.SUGGEST_COLUMN_TEXT_1,
71        SearchManager.SUGGEST_COLUMN_TEXT_2,
72    };
73
74    private static final String[] COLUMNS_WITHOUT_DESCRIPTION = new String[] {
75        "_id",
76        SearchManager.SUGGEST_COLUMN_QUERY,
77        SearchManager.SUGGEST_COLUMN_ICON_1,
78        SearchManager.SUGGEST_COLUMN_TEXT_1,
79    };
80
81    private final SearchEngineInfo mSearchEngineInfo;
82
83    private final AndroidHttpClient mHttpClient;
84
85    public OpenSearchSearchEngine(Context context, SearchEngineInfo searchEngineInfo) {
86        mSearchEngineInfo = searchEngineInfo;
87        mHttpClient = AndroidHttpClient.newInstance(USER_AGENT);
88        HttpParams params = mHttpClient.getParams();
89        params.setLongParameter(HTTP_TIMEOUT, HTTP_TIMEOUT_MS);
90    }
91
92    public String getName() {
93        return mSearchEngineInfo.getName();
94    }
95
96    public CharSequence getLabel() {
97        return mSearchEngineInfo.getLabel();
98    }
99
100    public void startSearch(Context context, String query, Bundle appData, String extraData) {
101        String uri = mSearchEngineInfo.getSearchUriForQuery(query);
102        if (uri == null) {
103            Log.e(TAG, "Unable to get search URI for " + mSearchEngineInfo);
104        } else {
105            Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(uri));
106            // Make sure the intent goes to the Browser itself
107            intent.setPackage(context.getPackageName());
108            intent.addCategory(Intent.CATEGORY_DEFAULT);
109            intent.putExtra(SearchManager.QUERY, query);
110            if (appData != null) {
111                intent.putExtra(SearchManager.APP_DATA, appData);
112            }
113            if (extraData != null) {
114                intent.putExtra(SearchManager.EXTRA_DATA_KEY, extraData);
115            }
116            intent.putExtra(Browser.EXTRA_APPLICATION_ID, context.getPackageName());
117            context.startActivity(intent);
118        }
119    }
120
121    /**
122     * Queries for a given search term and returns a cursor containing
123     * suggestions ordered by best match.
124     */
125    public Cursor getSuggestions(Context context, String query) {
126        if (TextUtils.isEmpty(query)) {
127            return null;
128        }
129        if (!isNetworkConnected(context)) {
130            Log.i(TAG, "Not connected to network.");
131            return null;
132        }
133
134        String suggestUri = mSearchEngineInfo.getSuggestUriForQuery(query);
135        if (TextUtils.isEmpty(suggestUri)) {
136            // No suggest URI available for this engine
137            return null;
138        }
139
140        try {
141            String content = readUrl(suggestUri);
142            if (content == null) return null;
143            /* The data format is a JSON array with items being regular strings or JSON arrays
144             * themselves. We are interested in the second and third elements, both of which
145             * should be JSON arrays. The second element/array contains the suggestions and the
146             * third element contains the descriptions. Some search engines don't support
147             * suggestion descriptions so the third element is optional.
148             */
149            JSONArray results = new JSONArray(content);
150            JSONArray suggestions = results.getJSONArray(1);
151            JSONArray descriptions = null;
152            if (results.length() > 2) {
153                descriptions = results.getJSONArray(2);
154                // Some search engines given an empty array "[]" for descriptions instead of
155                // not including it in the response.
156                if (descriptions.length() == 0) {
157                    descriptions = null;
158                }
159            }
160            return new SuggestionsCursor(suggestions, descriptions);
161        } catch (JSONException e) {
162            Log.w(TAG, "Error", e);
163        }
164        return null;
165    }
166
167    /**
168     * Executes a GET request and returns the response content.
169     *
170     * @param url Request URI.
171     * @return The response content. This is the empty string if the response
172     *         contained no content.
173     */
174    public String readUrl(String url) {
175        try {
176            HttpGet method = new HttpGet(url);
177            HttpResponse response = mHttpClient.execute(method);
178            if (response.getStatusLine().getStatusCode() == 200) {
179                return EntityUtils.toString(response.getEntity());
180            } else {
181                Log.i(TAG, "Suggestion request failed");
182                return null;
183            }
184        } catch (IOException e) {
185            Log.w(TAG, "Error", e);
186            return null;
187        }
188    }
189
190    public boolean supportsSuggestions() {
191        return mSearchEngineInfo.supportsSuggestions();
192    }
193
194    public void close() {
195        mHttpClient.close();
196    }
197
198    public boolean supportsVoiceSearch() {
199        return getName().equals(SearchEngine.GOOGLE);
200    }
201
202    private boolean isNetworkConnected(Context context) {
203        NetworkInfo networkInfo = getActiveNetworkInfo(context);
204        return networkInfo != null && networkInfo.isConnected();
205    }
206
207    private NetworkInfo getActiveNetworkInfo(Context context) {
208        ConnectivityManager connectivity =
209                (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
210        if (connectivity == null) {
211            return null;
212        }
213        return connectivity.getActiveNetworkInfo();
214    }
215
216    private static class SuggestionsCursor extends AbstractCursor {
217
218        private final JSONArray mSuggestions;
219
220        private final JSONArray mDescriptions;
221
222        public SuggestionsCursor(JSONArray suggestions, JSONArray descriptions) {
223            mSuggestions = suggestions;
224            mDescriptions = descriptions;
225        }
226
227        @Override
228        public int getCount() {
229            return mSuggestions.length();
230        }
231
232        @Override
233        public String[] getColumnNames() {
234            return (mDescriptions != null ? COLUMNS : COLUMNS_WITHOUT_DESCRIPTION);
235        }
236
237        @Override
238        public String getString(int column) {
239            if (mPos != -1) {
240                if ((column == COLUMN_INDEX_QUERY) || (column == COLUMN_INDEX_TEXT_1)) {
241                    try {
242                        return mSuggestions.getString(mPos);
243                    } catch (JSONException e) {
244                        Log.w(TAG, "Error", e);
245                    }
246                } else if (column == COLUMN_INDEX_TEXT_2) {
247                    try {
248                        return mDescriptions.getString(mPos);
249                    } catch (JSONException e) {
250                        Log.w(TAG, "Error", e);
251                    }
252                } else if (column == COLUMN_INDEX_ICON) {
253                    return String.valueOf(R.drawable.magnifying_glass);
254                }
255            }
256            return null;
257        }
258
259        @Override
260        public double getDouble(int column) {
261            throw new UnsupportedOperationException();
262        }
263
264        @Override
265        public float getFloat(int column) {
266            throw new UnsupportedOperationException();
267        }
268
269        @Override
270        public int getInt(int column) {
271            throw new UnsupportedOperationException();
272        }
273
274        @Override
275        public long getLong(int column) {
276            if (column == COLUMN_INDEX_ID) {
277                return mPos;        // use row# as the _Id
278            }
279            throw new UnsupportedOperationException();
280        }
281
282        @Override
283        public short getShort(int column) {
284            throw new UnsupportedOperationException();
285        }
286
287        @Override
288        public boolean isNull(int column) {
289            throw new UnsupportedOperationException();
290        }
291    }
292
293    @Override
294    public String toString() {
295        return "OpenSearchSearchEngine{" + mSearchEngineInfo + "}";
296    }
297
298}
299