[1/2] Add battery info to tvsettings device info

Change-Id: I98abe338d77b56f2a851e0f093a44d6911b9009b

packages/SettingsLib/src/com/android/settingslib/deviceinfo/AbstractBatteryStatusPreferenceController.java

+/*
+ * Copyright (C) 2019 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.settingslib.deviceinfo;
+
+import android.content.Context;
+import android.content.Intent;
+import android.content.IntentFilter;
+import android.os.BatteryManager;
+import android.os.Handler;
+import android.os.Message;
+
+import androidx.annotation.VisibleForTesting;
+import androidx.preference.Preference;
+import androidx.preference.PreferenceScreen;
+
+import com.android.settingslib.core.AbstractPreferenceController;
+import com.android.settingslib.core.lifecycle.Lifecycle;
+import com.android.settingslib.core.lifecycle.LifecycleObserver;
+import com.android.settingslib.core.lifecycle.events.OnStart;
+import com.android.settingslib.core.lifecycle.events.OnStop;
+import com.android.settingslib.R;
+
+import java.lang.ref.WeakReference;
+
+/**
+ * Preference controller for battery status
+ */
+public abstract class AbstractBatteryStatusPreferenceController extends AbstractPreferenceController
+        implements LifecycleObserver, OnStart, OnStop {
+
+    @VisibleForTesting
+    static final String KEY_BATTERY_STATUS = "battery_status";
+    private static final int EVENT_UPDATE_BATTERY = 700;
+
+    private Preference mBatteryStatus;
+    private Handler mHandler;
+    private Context mContext;
+
+    public AbstractBatteryStatusPreferenceController(Context context, Lifecycle lifecycle) {
+        super(context);
+        mContext = context;
+        if (lifecycle != null) {
+            lifecycle.addObserver(this);
+        }
+    }
+
+    @Override
+    public void onStart() {
+        getHandler().sendEmptyMessage(EVENT_UPDATE_BATTERY);
+    }
+
+    @Override
+    public void onStop() {
+        getHandler().removeMessages(EVENT_UPDATE_BATTERY);
+    }
+
+    @Override
+    public boolean isAvailable() {
+        Intent intent = mContext.registerReceiver(null,
+                new IntentFilter(Intent.ACTION_BATTERY_CHANGED));
+
+        return intent.getBooleanExtra(BatteryManager.EXTRA_PRESENT, false);
+    }
+
+    @Override
+    public String getPreferenceKey() {
+        return KEY_BATTERY_STATUS;
+    }
+
+    @Override
+    public void displayPreference(PreferenceScreen screen) {
+        super.displayPreference(screen);
+        mBatteryStatus = screen.findPreference(KEY_BATTERY_STATUS);
+        updateBattery();
+    }
+
+    private Handler getHandler() {
+        if (mHandler == null) {
+            mHandler = new BatteryStatusHandler(this);
+        }
+        return mHandler;
+    }
+
+    private void updateBattery() {
+        Intent intent = mContext.registerReceiver(null,
+                new IntentFilter(Intent.ACTION_BATTERY_CHANGED));
+
+        if (mBatteryStatus != null) {
+            String batterystatus = mContext.getString(R.string.battery_info_status_unknown);
+            String batterylevel = Integer.toString(Math.round(100.f
+                    * intent.getIntExtra(BatteryManager.EXTRA_LEVEL, 100)
+                    / intent.getIntExtra(BatteryManager.EXTRA_SCALE, 100))) + "%";
+
+            switch (intent.getIntExtra(BatteryManager.EXTRA_STATUS, -1)) {
+                case BatteryManager.BATTERY_STATUS_CHARGING:
+                    batterystatus = mContext.getString(R.string.battery_info_status_charging);
+                    break;
+                case BatteryManager.BATTERY_STATUS_DISCHARGING:
+                    batterystatus = mContext.getString(R.string.battery_info_status_discharging);
+                    break;
+                case BatteryManager.BATTERY_STATUS_FULL:
+                    batterystatus = mContext.getString(R.string.battery_info_status_full);
+                    break;
+                case BatteryManager.BATTERY_STATUS_NOT_CHARGING:
+                    batterystatus = mContext.getString(R.string.battery_info_status_not_charging);
+                    break;
+                case BatteryManager.BATTERY_STATUS_UNKNOWN:
+                default:
+                    break;
+            }
+
+            mBatteryStatus.setSummary(batterylevel + " - " + batterystatus);
+        }
+    }
+
+    private static class BatteryStatusHandler extends Handler {
+        private WeakReference<AbstractBatteryStatusPreferenceController> mStatus;
+
+        BatteryStatusHandler(AbstractBatteryStatusPreferenceController activity) {
+            mStatus = new WeakReference<>(activity);
+        }
+
+        @Override
+        public void handleMessage(Message msg) {
+            AbstractBatteryStatusPreferenceController status = mStatus.get();
+            if (status == null) {
+                return;
+            }
+
+            switch (msg.what) {
+                case EVENT_UPDATE_BATTERY:
+                    status.updateBattery();
+                    sendEmptyMessageDelayed(EVENT_UPDATE_BATTERY, 1000);
+                    break;
+
+                default:
+                    throw new IllegalStateException("Unknown message " + msg.what);
+            }
+        }
+    }
+}