1/*
2 * Copyright (C) 2014 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
17package android.provider;
18
19import android.content.ContentProvider;
20import android.content.ContentValues;
21import android.content.Context;
22import android.content.UriMatcher;
23import android.content.pm.ProviderInfo;
24import android.database.Cursor;
25import android.net.Uri;
26
27/**
28 * Base class for a search indexable provider. Such provider offers data to be indexed either
29 * as a reference to an XML file (like a {@link android.preference.PreferenceScreen}) or either
30 * as some raw data.
31 *
32 * @see SearchIndexableResource
33 * @see SearchIndexableData
34 * @see SearchIndexablesContract
35 *
36 * To create a search indexables provider, extend this class, then implement the abstract methods,
37 * and add it to your manifest like this:
38 *
39 * <pre class="prettyprint">&lt;manifest&gt;
40 *    ...
41 *    &lt;application&gt;
42 *        ...
43 *        &lt;provider
44 *            android:name="com.example.MyIndexablesProvider"
45 *            android:authorities="com.example.myindexablesprovider"
46 *            android:exported="true"
47 *            android:grantUriPermissions="true"
48 *            android:permission="android.permission.READ_SEARCH_INDEXABLES"
49 *            &lt;intent-filter&gt;
50 *                &lt;action android:name="android.content.action.SEARCH_INDEXABLES_PROVIDER" /&gt;
51 *            &lt;/intent-filter&gt;
52 *        &lt;/provider&gt;
53 *        ...
54 *    &lt;/application&gt;
55 *&lt;/manifest&gt;</pre>
56 * <p>
57 * When defining your provider, you must protect it with
58 * {@link android.Manifest.permission#READ_SEARCH_INDEXABLES}, which is a permission only the system
59 * can obtain.
60 * </p>
61 *
62 * @hide
63 */
64public abstract class SearchIndexablesProvider extends ContentProvider {
65    private static final String TAG = "IndexablesProvider";
66
67    private String mAuthority;
68    private UriMatcher mMatcher;
69
70    private static final int MATCH_RES_CODE = 1;
71    private static final int MATCH_RAW_CODE = 2;
72    private static final int MATCH_NON_INDEXABLE_KEYS_CODE = 3;
73
74    /**
75     * Implementation is provided by the parent class.
76     */
77    @Override
78    public void attachInfo(Context context, ProviderInfo info) {
79        mAuthority = info.authority;
80
81        mMatcher = new UriMatcher(UriMatcher.NO_MATCH);
82        mMatcher.addURI(mAuthority, SearchIndexablesContract.INDEXABLES_XML_RES_PATH,
83                MATCH_RES_CODE);
84        mMatcher.addURI(mAuthority, SearchIndexablesContract.INDEXABLES_RAW_PATH,
85                MATCH_RAW_CODE);
86        mMatcher.addURI(mAuthority, SearchIndexablesContract.NON_INDEXABLES_KEYS_PATH,
87                MATCH_NON_INDEXABLE_KEYS_CODE);
88
89        // Sanity check our setup
90        if (!info.exported) {
91            throw new SecurityException("Provider must be exported");
92        }
93        if (!info.grantUriPermissions) {
94            throw new SecurityException("Provider must grantUriPermissions");
95        }
96        if (!android.Manifest.permission.READ_SEARCH_INDEXABLES.equals(info.readPermission)) {
97            throw new SecurityException("Provider must be protected by READ_SEARCH_INDEXABLES");
98        }
99
100        super.attachInfo(context, info);
101    }
102
103    @Override
104    public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs,
105                        String sortOrder) {
106        switch (mMatcher.match(uri)) {
107            case MATCH_RES_CODE:
108                return queryXmlResources(null);
109            case MATCH_RAW_CODE:
110                return queryRawData(null);
111            case MATCH_NON_INDEXABLE_KEYS_CODE:
112                return queryNonIndexableKeys(null);
113            default:
114                throw new UnsupportedOperationException("Unknown Uri " + uri);
115        }
116    }
117
118    /**
119     * Returns all {@link android.provider.SearchIndexablesContract.XmlResource}.
120     *
121     * Those are Xml resource IDs to some {@link android.preference.PreferenceScreen}.
122     *
123     * @param projection list of {@link android.provider.SearchIndexablesContract.XmlResource}
124     *                   columns to put into the cursor. If {@code null} all supported columns
125     *                   should be included.
126     */
127    public abstract Cursor queryXmlResources(String[] projection);
128
129    /**
130     * Returns all {@link android.provider.SearchIndexablesContract.RawData}.
131     *
132     * Those are the raw indexable data.
133     *
134     * @param projection list of {@link android.provider.SearchIndexablesContract.RawData} columns
135     *                   to put into the cursor. If {@code null} all supported columns should be
136     *                   included.
137     */
138    public abstract Cursor queryRawData(String[] projection);
139
140    /**
141     * Returns all {@link android.provider.SearchIndexablesContract.NonIndexableKey}.
142     *
143     * Those are the non indexable data keys.
144     *
145     * @param projection list of {@link android.provider.SearchIndexablesContract.NonIndexableKey}
146     *                   columns to put into the cursor. If {@code null} all supported columns
147     *                   should be included.
148     */
149    public abstract Cursor queryNonIndexableKeys(String[] projection);
150
151    @Override
152    public String getType(Uri uri) {
153        switch (mMatcher.match(uri)) {
154            case MATCH_RES_CODE:
155                return SearchIndexablesContract.XmlResource.MIME_TYPE;
156            case MATCH_RAW_CODE:
157                return SearchIndexablesContract.RawData.MIME_TYPE;
158            case MATCH_NON_INDEXABLE_KEYS_CODE:
159                return SearchIndexablesContract.NonIndexableKey.MIME_TYPE;
160            default:
161                throw new IllegalArgumentException("Unknown URI " + uri);
162        }
163    }
164
165    /**
166     * Implementation is provided by the parent class. Throws by default, and cannot be overriden.
167     */
168    @Override
169    public final Uri insert(Uri uri, ContentValues values) {
170        throw new UnsupportedOperationException("Insert not supported");
171    }
172
173    /**
174     * Implementation is provided by the parent class. Throws by default, and cannot be overriden.
175     */
176    @Override
177    public final int delete(Uri uri, String selection, String[] selectionArgs) {
178        throw new UnsupportedOperationException("Delete not supported");
179    }
180
181    /**
182     * Implementation is provided by the parent class. Throws by default, and cannot be overriden.
183     */
184    @Override
185    public final int update(
186            Uri uri, ContentValues values, String selection, String[] selectionArgs) {
187        throw new UnsupportedOperationException("Update not supported");
188    }
189}
190