Cleanup to screensaver settings for O

Reworked the way screensaver settings are laid out for O. Instead of
using the options menu and dialogs to navigate screensaver options,
there are now two rows: one row for the screensaver choice and
optionally its own settings, and one row for the "when to show" setting.
And now there's a nice obvious button you can press to preview your
choices.

Test: 'export ROBOTEST_FILTER="RadioButtonListFragmentTest";\
mmm -j20 packages/apps/Settings/tests/robotests'

Bug: 35031991
Change-Id: Ie7d2055fb45f6dfe72e34cb9598d9a25f7bee75a

src/com/android/settings/dream/DreamSettings.java

@@ -0,0 +1,147 @@
+/*
+ * Copyright (C) 2017 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.dream;
+
+import android.provider.SearchIndexableResource;
+import android.support.annotation.VisibleForTesting;
+import com.android.settings.R;
+import com.android.settings.core.PreferenceController;
+import com.android.settings.dashboard.DashboardFragment;
+import com.android.settings.search.BaseSearchIndexProvider;
+import com.android.settingslib.dream.DreamBackend;
+import com.android.settingslib.dream.DreamBackend.WhenToDream;
+import java.util.ArrayList;
+import android.content.Context;
+import com.android.internal.logging.nano.MetricsProto.MetricsEvent;
+import java.util.Arrays;
+import java.util.List;
+
+import static com.android.settingslib.dream.DreamBackend.EITHER;
+import static com.android.settingslib.dream.DreamBackend.NEVER;
+import static com.android.settingslib.dream.DreamBackend.WHILE_CHARGING;
+import static com.android.settingslib.dream.DreamBackend.WHILE_DOCKED;
+
+public class DreamSettings extends DashboardFragment {
+
+    private static final String TAG = "DreamSettings";
+    static final String WHILE_CHARGING_ONLY = "while_charging_only";
+    static final String WHILE_DOCKED_ONLY = "while_docked_only";
+    static final String EITHER_CHARGING_OR_DOCKED = "either_charging_or_docked";
+    static final String NEVER_DREAM = "never";
+
+    @WhenToDream
+    static int getSettingFromPrefKey(String key) {
+        switch (key) {
+            case WHILE_CHARGING_ONLY:
+                return WHILE_CHARGING;
+            case WHILE_DOCKED_ONLY:
+                return WHILE_DOCKED;
+            case EITHER_CHARGING_OR_DOCKED:
+                return EITHER;
+            case NEVER_DREAM:
+            default:
+                return NEVER;
+        }
+    }
+
+    static String getKeyFromSetting(@WhenToDream int dreamSetting) {
+        switch (dreamSetting) {
+            case WHILE_CHARGING:
+                return WHILE_CHARGING_ONLY;
+            case WHILE_DOCKED:
+                return WHILE_DOCKED_ONLY;
+            case EITHER:
+                return EITHER_CHARGING_OR_DOCKED;
+            case NEVER:
+            default:
+                return NEVER_DREAM;
+        }
+    }
+
+    static int getDreamSettingDescriptionResId(@WhenToDream int dreamSetting) {
+        switch (dreamSetting) {
+            case WHILE_CHARGING:
+                return R.string.screensaver_settings_summary_sleep;
+            case WHILE_DOCKED:
+                return R.string.screensaver_settings_summary_dock;
+            case EITHER:
+                return R.string.screensaver_settings_summary_either_long;
+            case NEVER:
+            default:
+                return R.string.screensaver_settings_summary_never;
+        }
+    }
+
+    @Override
+    public int getMetricsCategory() {
+        return MetricsEvent.DREAM;
+    }
+
+    @Override
+    protected int getPreferenceScreenResId() {
+        return R.xml.dream_fragment_overview;
+    }
+
+    @Override
+    protected String getLogTag() {
+        return TAG;
+    }
+
+    @Override
+    protected List<PreferenceController> getPreferenceControllers(Context context) {
+        return buildPreferenceControllers(context);
+    }
+
+    public static CharSequence getSummaryTextWithDreamName(Context context) {
+        DreamBackend backend = DreamBackend.getInstance(context);
+        return getSummaryTextFromBackend(backend, context);
+    }
+
+    @VisibleForTesting
+    static CharSequence getSummaryTextFromBackend(DreamBackend backend, Context context) {
+        if (!backend.isEnabled()) {
+            return context.getString(R.string.screensaver_settings_summary_off);
+        } else {
+            return backend.getActiveDreamName();
+        }
+    }
+
+    private static List<PreferenceController> buildPreferenceControllers(Context context) {
+        List<PreferenceController> controllers = new ArrayList<>();
+        controllers.add(new CurrentDreamPreferenceController(context));
+        controllers.add(new WhenToDreamPreferenceController(context));
+        controllers.add(new StartNowPreferenceController(context));
+        return controllers;
+    }
+
+    public static final SearchIndexProvider SEARCH_INDEX_DATA_PROVIDER
+            = new BaseSearchIndexProvider() {
+                @Override
+                public List<SearchIndexableResource> getXmlResourcesToIndex(
+                        Context context, boolean enabled) {
+                    final SearchIndexableResource sir = new SearchIndexableResource(context);
+                    sir.xmlResId = R.xml.dream_fragment_overview;
+                    return Arrays.asList(sir);
+                }
+
+                @Override
+                public List<PreferenceController> getPreferenceControllers(Context context) {
+                    return buildPreferenceControllers(context);
+                }
+            };
+}
+