Add early warning tip and detector

When battery cannot make to usual charging time, this tip would
suggest user to turn on battery saver.

This tip has two visible state(NEW, HANDLED) and display different
information.

This cl also adds an action to turn on the battery saver.

Bug: 70570352
Test: RunSettingsRoboTests
Change-Id: I0e96554df12a0d6508c27174e16d8dca7f4e1fce

src/com/android/settings/fuelgauge/batterytip/tips/EarlyWarningTip.java

@@ -0,0 +1,93 @@
+/*
+ * 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 android.content.Context;
+import android.os.Parcel;
+
+import com.android.settings.R;
+
+/**
+ * Tip to show early warning if battery couldn't make to usual charging time
+ */
+public class EarlyWarningTip extends BatteryTip {
+    private boolean mPowerSaveModeOn;
+
+    public EarlyWarningTip(@StateType int state, boolean powerSaveModeOn) {
+        super(TipType.BATTERY_SAVER, state, false /* showDialog */);
+        mPowerSaveModeOn = powerSaveModeOn;
+    }
+
+    public EarlyWarningTip(Parcel in) {
+        super(in);
+        mPowerSaveModeOn = in.readBoolean();
+    }
+
+    @Override
+    public CharSequence getTitle(Context context) {
+        return context.getString(
+                mState == StateType.HANDLED
+                        ? R.string.battery_tip_early_heads_up_done_title
+                        : R.string.battery_tip_early_heads_up_title);
+    }
+
+    @Override
+    public CharSequence getSummary(Context context) {
+        return context.getString(
+                mState == StateType.HANDLED
+                        ? R.string.battery_tip_early_heads_up_done_summary
+                        : R.string.battery_tip_early_heads_up_summary);
+    }
+
+    @Override
+    public int getIconId() {
+        return mState == StateType.HANDLED
+                ? R.drawable.ic_perm_device_information_green_24dp
+                : R.drawable.ic_battery_alert_24dp;
+    }
+
+    @Override
+    public void updateState(BatteryTip tip) {
+        final EarlyWarningTip earlyHeadsUpTip = (EarlyWarningTip) tip;
+        if (mPowerSaveModeOn != earlyHeadsUpTip.mPowerSaveModeOn) {
+            mPowerSaveModeOn = earlyHeadsUpTip.mPowerSaveModeOn;
+            mState = earlyHeadsUpTip.mPowerSaveModeOn ? StateType.HANDLED : StateType.NEW;
+        } else if (mState != StateType.HANDLED) {
+            mState = earlyHeadsUpTip.getState();
+        }
+    }
+
+    @Override
+    public void writeToParcel(Parcel dest, int flags) {
+        super.writeToParcel(dest, flags);
+        dest.writeBoolean(mPowerSaveModeOn);
+    }
+
+    public boolean isPowerSaveModeOn() {
+        return mPowerSaveModeOn;
+    }
+
+    public static final Creator CREATOR = new Creator() {
+        public BatteryTip createFromParcel(Parcel in) {
+            return new EarlyWarningTip(in);
+        }
+
+        public BatteryTip[] newArray(int size) {
+            return new EarlyWarningTip[size];
+        }
+    };
+}