Update and expose the low battery tip.

This tip was punted however we need to bring it back to P. It happens
when battery level is low or remaining time is less than 3 hour. The
suggestion is to turn on battery saver.

1. Extend tip from EarlyWarningTip since it has most common logic
2. Update the detector to align it to battery saver notifcation in
systemui.
3. Update tip order to surface low battery tip.

Follow CL will:
1. Hook up the low battery threshold to server side
2. Add test stub for this tip, so we could trigger it by adb.

Change-Id: I14f9696a549393bf980e31838fb86afd5d9efbc7
Bug: 76113067
Test: RunSettingsRoboTests

tests/robotests/src/com/android/settings/fuelgauge/batterytip/BatteryTipLoaderTest.java

@@ -48,9 +48,9 @@ public class BatteryTipLoaderTest {
             BatteryTip.TipType.APP_RESTRICTION,
             BatteryTip.TipType.BATTERY_SAVER,
             BatteryTip.TipType.HIGH_DEVICE_USAGE,
+            BatteryTip.TipType.LOW_BATTERY,
             BatteryTip.TipType.SUMMARY,
-            BatteryTip.TipType.SMART_BATTERY_MANAGER,
-            BatteryTip.TipType.LOW_BATTERY};
+            BatteryTip.TipType.SMART_BATTERY_MANAGER};
     @Mock(answer = Answers.RETURNS_DEEP_STUBS)
     private BatteryStatsHelper mBatteryStatsHelper;
     @Mock

tests/robotests/src/com/android/settings/fuelgauge/batterytip/detectors/LowBatteryDetectorTest.java

@@ -17,12 +17,15 @@
 package com.android.settings.fuelgauge.batterytip.detectors;
 
 import static com.google.common.truth.Truth.assertThat;
+
 import static org.mockito.Mockito.spy;
 
-import android.text.format.DateUtils;
+import android.content.Context;
+import android.os.PowerManager;
 
 import com.android.settings.fuelgauge.BatteryInfo;
 import com.android.settings.fuelgauge.batterytip.BatteryTipPolicy;
+import com.android.settings.fuelgauge.batterytip.tips.BatteryTip;
 import com.android.settings.testutils.SettingsRobolectricTestRunner;
 
 import org.junit.Before;
@@ -31,8 +34,12 @@ import org.junit.runner.RunWith;
 import org.mockito.Mock;
 import org.mockito.MockitoAnnotations;
 import org.robolectric.RuntimeEnvironment;
+import org.robolectric.Shadows;
+import org.robolectric.shadows.ShadowPowerManager;
 import org.robolectric.util.ReflectionHelpers;
 
+import java.util.concurrent.TimeUnit;
+
 @RunWith(SettingsRobolectricTestRunner.class)
 public class LowBatteryDetectorTest {
 
@@ -40,36 +47,60 @@ public class LowBatteryDetectorTest {
     private BatteryInfo mBatteryInfo;
     private BatteryTipPolicy mPolicy;
     private LowBatteryDetector mLowBatteryDetector;
+    private ShadowPowerManager mShadowPowerManager;
+    private Context mContext;
 
     @Before
     public void setUp() {
         MockitoAnnotations.initMocks(this);
 
         mPolicy = spy(new BatteryTipPolicy(RuntimeEnvironment.application));
+        mContext = RuntimeEnvironment.application;
+        mShadowPowerManager = Shadows.shadowOf(mContext.getSystemService(PowerManager.class));
         ReflectionHelpers.setField(mPolicy, "lowBatteryEnabled", true);
+        mBatteryInfo.discharging = true;
 
-        mLowBatteryDetector = new LowBatteryDetector(mPolicy, mBatteryInfo);
+        mLowBatteryDetector = new LowBatteryDetector(mContext, mPolicy, mBatteryInfo);
     }
 
     @Test
     public void testDetect_disabledByPolicy_tipInvisible() {
         ReflectionHelpers.setField(mPolicy, "lowBatteryEnabled", false);
+        mShadowPowerManager.setIsPowerSaveMode(true);
 
         assertThat(mLowBatteryDetector.detect().isVisible()).isFalse();
     }
 
     @Test
-    public void testDetect_shortBatteryLife_tipVisible() {
-        mBatteryInfo.discharging = true;
-        mBatteryInfo.remainingTimeUs = DateUtils.MINUTE_IN_MILLIS;
+    public void testDetect_lowBattery_tipNew() {
+        mBatteryInfo.batteryLevel = 3;
+        mBatteryInfo.remainingTimeUs = TimeUnit.DAYS.toMillis(1);
+        assertThat(mLowBatteryDetector.detect().getState()).isEqualTo(BatteryTip.StateType.NEW);
 
-        assertThat(mLowBatteryDetector.detect().isVisible()).isTrue();
+        mBatteryInfo.batteryLevel = 50;
+        mBatteryInfo.remainingTimeUs = TimeUnit.MINUTES.toMillis(1);
+        assertThat(mLowBatteryDetector.detect().getState()).isEqualTo(BatteryTip.StateType.NEW);
     }
 
     @Test
-    public void testDetect_longBatteryLife_tipInvisible() {
-        mBatteryInfo.discharging = true;
-        mBatteryInfo.remainingTimeUs = DateUtils.DAY_IN_MILLIS;
+    public void testDetect_batterySaverOn_tipHandled() {
+        mShadowPowerManager.setIsPowerSaveMode(true);
+
+        assertThat(mLowBatteryDetector.detect().getState())
+                .isEqualTo(BatteryTip.StateType.HANDLED);
+    }
+
+    @Test
+    public void testDetect_charging_tipInvisible() {
+        mBatteryInfo.discharging = false;
+
+        assertThat(mLowBatteryDetector.detect().isVisible()).isFalse();
+    }
+
+    @Test
+    public void testDetect_noEarlyWarning_tipInvisible() {
+        mBatteryInfo.remainingTimeUs = TimeUnit.DAYS.toMicros(1);
+        mBatteryInfo.batteryLevel = 100;
 
         assertThat(mLowBatteryDetector.detect().isVisible()).isFalse();
     }

tests/robotests/src/com/android/settings/fuelgauge/batterytip/tips/LowBatteryTipTest.java

@@ -0,0 +1,89 @@
+/*
+ * 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.batterytip.tips;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import static org.mockito.Mockito.verify;
+
+import android.content.Context;
+import android.os.Parcel;
+
+import com.android.internal.logging.nano.MetricsProto;
+import com.android.settings.R;
+import com.android.settings.testutils.SettingsRobolectricTestRunner;
+import com.android.settingslib.core.instrumentation.MetricsFeatureProvider;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+import org.robolectric.RuntimeEnvironment;
+
+@RunWith(SettingsRobolectricTestRunner.class)
+public class LowBatteryTipTest {
+
+    private static final CharSequence SUMMARY = "Only 15 minutes left";
+
+    @Mock
+    private MetricsFeatureProvider mMetricsFeatureProvider;
+    private Context mContext;
+    private LowBatteryTip mLowBatteryTip;
+
+    @Before
+    public void setUp() {
+        MockitoAnnotations.initMocks(this);
+
+        mContext = RuntimeEnvironment.application;
+        mLowBatteryTip = new LowBatteryTip(BatteryTip.StateType.NEW, false /* powerSaveModeOn */,
+                SUMMARY);
+    }
+
+    @Test
+    public void testParcelable() {
+        Parcel parcel = Parcel.obtain();
+        mLowBatteryTip.writeToParcel(parcel, mLowBatteryTip.describeContents());
+        parcel.setDataPosition(0);
+
+        final LowBatteryTip parcelTip = new LowBatteryTip(parcel);
+
+        assertThat(parcelTip.isPowerSaveModeOn()).isFalse();
+        assertThat(parcelTip.getSummary(mContext)).isEqualTo(SUMMARY);
+    }
+
+    @Test
+    public void getSummary_tipHandled_showSummary() {
+        mLowBatteryTip.mState = BatteryTip.StateType.HANDLED;
+
+        assertThat(mLowBatteryTip.getSummary(mContext)).isEqualTo("Some features may be limited");
+    }
+
+    @Test
+    public void getSummary_tipNew_showSummary() {
+        mLowBatteryTip.mState = BatteryTip.StateType.NEW;
+
+        assertThat(mLowBatteryTip.getSummary(mContext)).isEqualTo(SUMMARY);
+    }
+
+    @Test
+    public void log_lowBatteryActionWithCorrectState() {
+        mLowBatteryTip.log(mContext, mMetricsFeatureProvider);
+
+        verify(mMetricsFeatureProvider).action(mContext,
+                MetricsProto.MetricsEvent.ACTION_LOW_BATTERY_TIP, BatteryTip.StateType.NEW);
+    }
+}