Add Indexable.SearchIndexProvider.getNonIndexableKeys(Context)

- getNonIndexableKeys(Context) allow a SearchIndexProvider to tell which data
he does not want to index by providing a list of the data keys
- use this new API for SoundSettings and removing KEY_EMERGENCY_TONE related
settings if the device is not CDMA
- add a BaseSearchIndexProvider for code simplification

Change-Id: I23633ace1d7e390ee05fac0a5458a33e04e72d8d

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

@@ -0,0 +1,49 @@
+/*
+ * 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.Collections;
+import java.util.List;
+
+/**
+ * A basic SearchIndexProvider that returns no data to index.
+ */
+public class BaseSearchIndexProvider implements Indexable.SearchIndexProvider {
+
+    private static final List<String> EMPTY_LIST = Collections.<String>emptyList();
+
+    public BaseSearchIndexProvider() {
+    }
+
+    @Override
+    public List<SearchIndexableResource> getXmlResourcesToIndex(Context context, boolean enabled) {
+        return null;
+    }
+
+    @Override
+    public List<SearchIndexableRaw> getRawDataToIndex(Context context, boolean enabled) {
+        return null;
+    }
+
+    @Override
+    public List<String> getNonIndexableKeys(Context context) {
+        return EMPTY_LIST;
+    }
+}