content: /*
   * Copyright (C) 2014 The Android Open Source Project
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package android.provider;
  
  import android.annotation.Nullable;
  import android.annotation.SystemApi;
  import android.app.slice.Slice;
  import android.content.ContentProvider;
  import android.content.ContentValues;
  import android.content.Context;
  import android.content.UriMatcher;
  import android.content.pm.ProviderInfo;
  import android.database.Cursor;
  import android.net.Uri;
  import android.util.Log;
  
  /**
   * Base class for a search indexable provider. Such provider offers data to be indexed either
   * as a reference to an XML file (like a {@link android.preference.PreferenceScreen}) or either
   * as some raw data.
   *
   * @see SearchIndexableResource
   * @see SearchIndexableData
   * @see SearchIndexablesContract
   *
   * To create a search indexables provider, extend this class, then implement the abstract methods,
   * and add it to your manifest like this:
   *
   * <pre class="prettyprint">&lt;manifest&gt;
   *    ...
   *    &lt;application&gt;
   *        ...
   *        &lt;provider
   *            android:name="com.example.MyIndexablesProvider"
   *            android:authorities="com.example.myindexablesprovider"
   *            android:exported="true"
   *            android:grantUriPermissions="true"
   *            android:permission="android.permission.READ_SEARCH_INDEXABLES"
   *            &lt;intent-filter&gt;
   *                &lt;action android:name="android.content.action.SEARCH_INDEXABLES_PROVIDER" /&gt;
   *            &lt;/intent-filter&gt;
   *        &lt;/provider&gt;
   *        ...
   *    &lt;/application&gt;
   *&lt;/manifest&gt;</pre>
   * <p>
   * When defining your provider, you must protect it with
   * {@link android.Manifest.permission#READ_SEARCH_INDEXABLES}, which is a permission only the system
   * can obtain.
   * </p>
   *
   * @hide
   */
  @SystemApi
  public abstract class SearchIndexablesProvider extends ContentProvider {
      private static final String TAG = "IndexablesProvider";
  
      private String mAuthority;
      private UriMatcher mMatcher;
  
      private static final int MATCH_RES_CODE = 1;
      private static final int MATCH_RAW_CODE = 2;
      private static final int MATCH_NON_INDEXABLE_KEYS_CODE = 3;
      private static final int MATCH_SITE_MAP_PAIRS_CODE = 4;
      private static final int MATCH_SLICE_URI_PAIRS_CODE = 5;
  
      /**
       * Implementation is provided by the parent class.
       */
      @Override
      public void attachInfo(Context context, ProviderInfo info) {
          mAuthority = info.authority;
  
          mMatcher = new UriMatcher(UriMatcher.NO_MATCH);
          mMatcher.addURI(mAuthority, SearchIndexablesContract.INDEXABLES_XML_RES_PATH,
                  MATCH_RES_CODE);
          mMatcher.addURI(mAuthority, SearchIndexablesContract.INDEXABLES_RAW_PATH,
                  MATCH_RAW_CODE);
          mMatcher.addURI(mAuthority, SearchIndexablesContract.NON_INDEXABLES_KEYS_PATH,
                  MATCH_NON_INDEXABLE_KEYS_CODE);
          mMatcher.addURI(mAuthority, SearchIndexablesContract.SITE_MAP_PAIRS_PATH,
                  MATCH_SITE_MAP_PAIRS_CODE);
          mMatcher.addURI(mAuthority, SearchIndexablesContract.SLICE_URI_PAIRS_PATH,
                  MATCH_SLICE_URI_PAIRS_CODE);
  
          // Sanity check our setup
          if (!info.exported) {
              throw new SecurityException("Provider must be exported");
          }
          if (!info.grantUriPermissions) {
              throw new SecurityException("Provider must grantUriPermissions");
          }
          if (!android.Manifest.permission.READ_SEARCH_INDEXABLES.equals(info.readPermission)) {
              throw new SecurityException("Provider must be protected by READ_SEARCH_INDEXABLES");
          }
  
          super.attachInfo(context, info);
      }
  
      @Override
      public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs,
                          String sortOrder) {
          try {
              switch (mMatcher.match(uri)) {
                  case MATCH_RES_CODE:
                      return queryXmlResources(null);
                  case MATCH_RAW_CODE:
                      return queryRawData(null);
                  case MATCH_NON_INDEXABLE_KEYS_CODE:
                      return queryNonIndexableKeys(null);
                  case MATCH_SITE_MAP_PAIRS_CODE:
                      return querySiteMapPairs();
                  case MATCH_SLICE_URI_PAIRS_CODE:
                      return querySliceUriPairs();
                  default:
                      throw new UnsupportedOperationException("Unknown Uri " + uri);
              }
          } catch (UnsupportedOperationException e) {
              throw e;
          } catch (Exception e) {
              Log.e(TAG, "Provider querying exception:", e);
              return null;
          }
      }
  
      /**
       * Returns all {@link android.provider.SearchIndexablesContract.XmlResource}.
       *
       * Those are Xml resource IDs to some {@link android.preference.PreferenceScreen}.
       *
       * @param projection list of {@link android.provider.SearchIndexablesContract.XmlResource}
       *                   columns to put into the cursor. If {@code null} all supported columns
       *                   should be included.
       */
      public abstract Cursor queryXmlResources(String[] projection);
  
      /**
       * Returns all {@link android.provider.SearchIndexablesContract.RawData}.
       *
       * Those are the raw indexable data.
       *
       * @param projection list of {@link android.provider.SearchIndexablesContract.RawData} columns
       *                   to put into the cursor. If {@code null} all supported columns should be
       *                   included.
       */
      public abstract Cursor queryRawData(String[] projection);
  
      /**
       * Returns all {@link android.provider.SearchIndexablesContract.NonIndexableKey}.
       *
       * Those are the non indexable data keys.
       *
       * @param projection list of {@link android.provider.SearchIndexablesContract.NonIndexableKey}
       *                   columns to put into the cursor. If {@code null} all supported columns
       *                   should be included.
       */
      public abstract Cursor queryNonIndexableKeys(String[] projection);
  
      /**
       * Returns a {@link Cursor}, where rows are [parent class, child class] entries to form a site
       * map. The list of pairs should be as complete as possible.
       *
       * @hide
       */
      public Cursor querySiteMapPairs() {
          // By default no-op.
          return null;
      }
  
      /**
       * Returns a {@link Cursor} linking {@link Slice} {@link Uri Uris} to the
       * corresponding Settings key.
       */
      @Nullable
      public Cursor querySliceUriPairs() {
          // By default no-op;
          return null;
      }
  
      @Override
      public String getType(Uri uri) {
          switch (mMatcher.match(uri)) {
              case MATCH_RES_CODE:
                  return SearchIndexablesContract.XmlResource.MIME_TYPE;
              case MATCH_RAW_CODE:
                  return SearchIndexablesContract.RawData.MIME_TYPE;
              case MATCH_NON_INDEXABLE_KEYS_CODE:
                  return SearchIndexablesContract.NonIndexableKey.MIME_TYPE;
              default:
                  throw new IllegalArgumentException("Unknown URI " + uri);
          }
      }
  
      /**
       * Implementation is provided by the parent class. Throws by default, and cannot be overridden.
       */
      @Override
      public final Uri insert(Uri uri, ContentValues values) {
          throw new UnsupportedOperationException("Insert not supported");
      }
  
      /**
       * Implementation is provided by the parent class. Throws by default, and cannot be overridden.
       */
      @Override
      public final int delete(Uri uri, String selection, String[] selectionArgs) {
          throw new UnsupportedOperationException("Delete not supported");
      }
  
      /**
       * Implementation is provided by the parent class. Throws by default, and cannot be overridden.
       */
      @Override
      public final int update(
              Uri uri, ContentValues values, String selection, String[] selectionArgs) {
          throw new UnsupportedOperationException("Update not supported");
      }
  }
  