Hook up smart battery to Settings value.

Bug: 71502850
Test: RunSettingsRoboTests
Change-Id: Icbc99af8f681e67af54e3509b3eec40ac9d9668e

src/com/android/settings/fuelgauge/SmartBatteryPreferenceController.java

@@ -18,7 +18,9 @@
 package com.android.settings.fuelgauge;
 
 import android.content.Context;
+import android.provider.Settings;
 import android.support.annotation.VisibleForTesting;
+import android.support.v14.preference.SwitchPreference;
 import android.support.v7.preference.Preference;
 
 import com.android.settings.applications.LayoutPreference;
@@ -30,6 +32,8 @@ import com.android.settings.core.BasePreferenceController;
 public class SmartBatteryPreferenceController extends BasePreferenceController implements
         Preference.OnPreferenceChangeListener {
     private static final String KEY_SMART_BATTERY = "smart_battery";
+    private static final int ON = 1;
+    private static final int OFF = 0;
 
     public SmartBatteryPreferenceController(Context context) {
         super(context, KEY_SMART_BATTERY);
@@ -37,18 +41,23 @@ public class SmartBatteryPreferenceController extends BasePreferenceController i
 
     @Override
     public int getAvailabilityStatus() {
+        // TODO(b/71502850): get Availability from API. The device may not support it.
         return AVAILABLE;
     }
 
     @Override
     public void updateState(Preference preference) {
         super.updateState(preference);
+        final boolean smartBatteryOn = Settings.Global.getInt(mContext.getContentResolver(),
+                Settings.Global.APP_STANDBY_ENABLED, ON) == ON;
+        ((SwitchPreference) preference).setChecked(smartBatteryOn);
     }
 
     @Override
     public boolean onPreferenceChange(Preference preference, Object newValue) {
         final boolean smartBatteryOn = (Boolean) newValue;
-        //TODO(b/71502850): use smart battery API here to update the state
+        Settings.Global.putInt(mContext.getContentResolver(), Settings.Global.APP_STANDBY_ENABLED,
+                smartBatteryOn ? ON : OFF);
         return true;
     }
 }

tests/robotests/src/com/android/settings/fuelgauge/SmartBatteryPreferenceControllerTest.java

@@ -0,0 +1,95 @@
+/*
+ * Copyright (C) 2018 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.fuelgauge;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import android.content.Context;
+import android.provider.Settings;
+import android.support.v14.preference.SwitchPreference;
+
+import com.android.settings.TestConfig;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.MockitoAnnotations;
+import org.robolectric.RobolectricTestRunner;
+import org.robolectric.RuntimeEnvironment;
+import org.robolectric.annotation.Config;
+
+@RunWith(RobolectricTestRunner.class)
+@Config(manifest = TestConfig.MANIFEST_PATH, sdk = TestConfig.SDK_VERSION)
+public class SmartBatteryPreferenceControllerTest {
+    private static final int ON = 1;
+    private static final int OFF = 0;
+
+    private SmartBatteryPreferenceController mController;
+    private SwitchPreference mPreference;
+    private Context mContext;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+
+        mContext = RuntimeEnvironment.application;
+        mController = new SmartBatteryPreferenceController(mContext);
+        mPreference = new SwitchPreference(mContext);
+    }
+
+    @Test
+    public void testUpdateState_smartBatteryOn_preferenceChecked() {
+        putSmartBatteryValue(ON);
+
+        mController.updateState(mPreference);
+
+        assertThat(mPreference.isChecked()).isTrue();
+    }
+
+    @Test
+    public void testUpdateState_smartBatteryOff_preferenceUnchecked() {
+        putSmartBatteryValue(OFF);
+
+        mController.updateState(mPreference);
+
+        assertThat(mPreference.isChecked()).isFalse();
+    }
+
+    @Test
+    public void testUpdateState_checkPreference_smartBatteryOn() {
+        mController.onPreferenceChange(mPreference, true);
+
+        assertThat(getSmartBatteryValue()).isEqualTo(ON);
+    }
+
+    @Test
+    public void testUpdateState_unCheckPreference_smartBatteryOff() {
+        mController.onPreferenceChange(mPreference, false);
+
+        assertThat(getSmartBatteryValue()).isEqualTo(OFF);
+    }
+
+    private void putSmartBatteryValue(int value) {
+        Settings.Global.putInt(mContext.getContentResolver(), Settings.Global.APP_STANDBY_ENABLED,
+                value);
+    }
+
+    private int getSmartBatteryValue() {
+        return Settings.Global.getInt(mContext.getContentResolver(),
+                Settings.Global.APP_STANDBY_ENABLED, ON);
+    }
+}