Add external Preferences indexing

- define SettingsSearchIndexablesProvider as an internal
SearchIndexablesProvider
- protect access thru using android.permission.READ_SEARCH_INDEXABLES
- update WallpaperTypeSettings and WifiSettings for taking care of
the new model
- update the Dashboard for taking care about external Icons for the
search result
- update sqlite model/version for taking care about Intents
(enable launching external applications for showing the settings)

Change-Id: I2e38599327e6480f1754f52666becce0884cee9d

src/com/android/settings/search/Indexable.java

@@ -0,0 +1,56 @@
+/*
+ * 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 com.android.settings.search;
+
+import android.content.Context;
+import android.provider.SearchIndexableResource;
+
+import java.util.List;
+
+/**
+ * Interface for classes whose instances can provide data for indexing.
+ *
+ * Classes implementing the Indexable interface must have a static field called
+ * <code>SEARCH_INDEX_DATA_PROVIDER</code>, which is an object implementing the
+ * {@link Indexable.SearchIndexProvider} interface.
+ *
+ * See {@link android.provider.SearchIndexableResource} and {@link SearchIndexableRaw}.
+ *
+ */
+public interface Indexable {
+
+    public interface SearchIndexProvider {
+        /**
+         * Return a list of references for indexing.
+         *
+         * See {@link android.provider.SearchIndexableResource}
+         *
+         * @param context the context
+         * @return a list of {@link android.provider.SearchIndexableResource} references.
+         *         Can be null.
+         */
+        List<SearchIndexableResource> getXmlResourcesToIndex(Context context);
+
+        /**
+         * Return a list of raw data for indexing. See {@link SearchIndexableRaw}
+         *
+         * @param context the context
+         * @return a list of {@link SearchIndexableRaw} references. Can be null.
+         */
+        List<SearchIndexableRaw> getRawDataToIndex(Context context);
+    }
+}