Add warning message when power save mode is enabled for smart auto rotate settings fragment

Test: locally with flame, make RunSettingsRoboTests -j96
ROBOTEST_FILTER=SmartAutoRotateBatterySaverControllerTest,SmartAutoRotateControllerTest

Bug: 186690152
Change-Id: Ibac90a4edd4631e8256da79d0594ac7704b5f8f7

src/com/android/settings/display/SmartAutoRotateBatterySaverController.java

@@ -0,0 +1,96 @@
+/*
+ * Copyright (C) 2021 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.display;
+
+import static com.android.settings.display.SmartAutoRotateController.isRotationResolverServiceAvailable;
+
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import android.content.IntentFilter;
+import android.os.PowerManager;
+
+import androidx.annotation.VisibleForTesting;
+import androidx.lifecycle.LifecycleObserver;
+import androidx.preference.Preference;
+import androidx.preference.PreferenceScreen;
+
+import com.android.settings.R;
+import com.android.settings.core.BasePreferenceController;
+import com.android.settingslib.core.lifecycle.events.OnStart;
+import com.android.settingslib.core.lifecycle.events.OnStop;
+import com.android.settingslib.widget.BannerMessagePreference;
+
+/**
+ * The controller of camera based rotate battery saver warning preference. The preference appears
+ * when battery saver mode is enabled.
+ */
+public class SmartAutoRotateBatterySaverController extends BasePreferenceController implements
+        LifecycleObserver, OnStart, OnStop {
+
+    private Preference mPreference;
+    private final PowerManager mPowerManager;
+    private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
+        @Override
+        public void onReceive(Context context, Intent intent) {
+            if (mPreference == null) {
+                return;
+            }
+            mPreference.setVisible(isPowerSaveMode());
+            updateState(mPreference);
+        }
+    };
+
+    public SmartAutoRotateBatterySaverController(Context context, String key) {
+        super(context, key);
+        mPowerManager = context.getSystemService(PowerManager.class);
+    }
+
+    @VisibleForTesting
+    boolean isPowerSaveMode() {
+        return mPowerManager.isPowerSaveMode();
+    }
+
+    @Override
+    public void displayPreference(PreferenceScreen screen) {
+        super.displayPreference(screen);
+        mPreference = screen.findPreference(getPreferenceKey());
+        ((BannerMessagePreference) mPreference)
+                .setPositiveButtonText(R.string.disable_text)
+                .setPositiveButtonOnClickListener(v -> {
+                    mPowerManager.setPowerSaveModeEnabled(false);
+                });
+    }
+
+    @Override
+    public void onStart() {
+        mContext.registerReceiver(mReceiver,
+                new IntentFilter(PowerManager.ACTION_POWER_SAVE_MODE_CHANGED));
+    }
+
+    @Override
+    public void onStop() {
+        mContext.unregisterReceiver(mReceiver);
+    }
+
+    @Override
+    @AvailabilityStatus
+    public int getAvailabilityStatus() {
+        return isRotationResolverServiceAvailable(mContext)
+                && isPowerSaveMode() ? AVAILABLE_UNSEARCHABLE : UNSUPPORTED_ON_DEVICE;
+    }
+}