Source code
Revision control
Copy as Markdown
Other Tools
/* -*- Mode: Java; c-basic-offset: 4; tab-width: 4; indent-tabs-mode: nil; -*-
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
package org.mozilla.gecko;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.BatteryManager;
import android.os.Build;
import android.os.SystemClock;
import android.util.Log;
import org.mozilla.gecko.annotation.WrapForJNI;
public class GeckoBatteryManager extends BroadcastReceiver {
private static final String LOGTAG = "GeckoBatteryManager";
// Those constants should be keep in sync with the ones in:
// dom/battery/Constants.h
private static final double kDefaultLevel = 1.0;
private static final boolean kDefaultCharging = true;
private static final double kDefaultRemainingTime = 0.0;
private static final double kUnknownRemainingTime = -1.0;
private static long sLastLevelChange;
private static boolean sNotificationsEnabled;
private static double sLevel = kDefaultLevel;
private static boolean sCharging = kDefaultCharging;
private static double sRemainingTime = kDefaultRemainingTime;
private static final GeckoBatteryManager sInstance = new GeckoBatteryManager();
private final IntentFilter mFilter;
private Context mApplicationContext;
private boolean mIsEnabled;
public static GeckoBatteryManager getInstance() {
return sInstance;
}
private GeckoBatteryManager() {
mFilter = new IntentFilter();
mFilter.addAction(Intent.ACTION_BATTERY_CHANGED);
}
public synchronized void start(final Context context) {
if (mIsEnabled) {
Log.w(LOGTAG, "Already started!");
return;
}
mApplicationContext = context.getApplicationContext();
// registerReceiver will return null if registering fails.
final Intent intent = mApplicationContext.registerReceiver(this, mFilter);
if (intent == null) {
Log.e(LOGTAG, "Registering receiver failed");
return;
}
mIsEnabled = true;
final double current = intent.getIntExtra(BatteryManager.EXTRA_LEVEL, -1);
final double max = intent.getIntExtra(BatteryManager.EXTRA_SCALE, -1);
if (current == -1 || max == -1) {
Log.e(LOGTAG, "Failed to get battery level!");
sLevel = kDefaultLevel;
} else {
sLevel = current / max;
}
}
public synchronized void stop() {
if (!mIsEnabled) {
Log.w(LOGTAG, "Already stopped!");
return;
}
mApplicationContext.unregisterReceiver(this);
mApplicationContext = null;
mIsEnabled = false;
}
@WrapForJNI(calledFrom = "ui", dispatchTo = "gecko")
private static native void onBatteryChange(double level, boolean charging, double remainingTime);
@Override
public void onReceive(final Context context, final Intent intent) {
if (!intent.getAction().equals(Intent.ACTION_BATTERY_CHANGED)) {
Log.e(LOGTAG, "Got an unexpected intent!");
return;
}
final boolean previousCharging = isCharging();
final double previousLevel = getLevel();
// NOTE: it might not be common (in 2012) but technically, Android can run
// on a device that has no battery so we want to make sure it's not the case
// before bothering checking for battery state.
// However, the Galaxy Nexus phone advertises itself as battery-less which
// force us to special-case the logic.
if (intent.getBooleanExtra(BatteryManager.EXTRA_PRESENT, false)
|| Build.MODEL.equals("Galaxy Nexus")) {
final int plugged = intent.getIntExtra(BatteryManager.EXTRA_PLUGGED, -1);
if (plugged == -1) {
sCharging = kDefaultCharging;
Log.e(LOGTAG, "Failed to get the plugged status!");
} else {
// Likely, if plugged > 0, it's likely plugged and charging but the doc
// isn't clear about that.
sCharging = plugged != 0;
}
if (sCharging != previousCharging) {
sRemainingTime = kUnknownRemainingTime;
// The new remaining time is going to take some time to show up but
// it's the best way to show a not too wrong value.
sLastLevelChange = 0;
}
// We need two doubles because sLevel is a double.
final double current = intent.getIntExtra(BatteryManager.EXTRA_LEVEL, -1);
final double max = intent.getIntExtra(BatteryManager.EXTRA_SCALE, -1);
if (current == -1 || max == -1) {
Log.e(LOGTAG, "Failed to get battery level!");
sLevel = kDefaultLevel;
} else {
sLevel = current / max;
}
if (sLevel == 1.0 && sCharging) {
sRemainingTime = kDefaultRemainingTime;
} else if (sLevel != previousLevel) {
// Estimate remaining time.
if (sLastLevelChange != 0) {
// Use elapsedRealtime() because we want to track time across device sleeps.
final long currentTime = SystemClock.elapsedRealtime();
final long dt = (currentTime - sLastLevelChange) / 1000;
final double dLevel = sLevel - previousLevel;
if (sCharging) {
if (dLevel < 0) {
sRemainingTime = kUnknownRemainingTime;
} else {
sRemainingTime = Math.round(dt / dLevel * (1.0 - sLevel));
}
} else {
if (dLevel > 0) {
Log.w(LOGTAG, "When discharging, level should decrease!");
sRemainingTime = kUnknownRemainingTime;
} else {
sRemainingTime = Math.round(dt / -dLevel * sLevel);
}
}
sLastLevelChange = currentTime;
} else {
// That's the first time we got an update, we can't do anything.
sLastLevelChange = SystemClock.elapsedRealtime();
}
}
} else {
sLevel = kDefaultLevel;
sCharging = kDefaultCharging;
sRemainingTime = kDefaultRemainingTime;
}
/*
* We want to inform listeners if the following conditions are fulfilled:
* - we have at least one observer;
* - the charging state or the level has changed.
*
* Note: no need to check for a remaining time change given that it's only
* updated if there is a level change or a charging change.
*
* The idea is to prevent doing all the way to the DOM code in the child
* process to finally not send an event.
*/
if (sNotificationsEnabled
&& (previousCharging != isCharging() || previousLevel != getLevel())) {
onBatteryChange(getLevel(), isCharging(), getRemainingTime());
}
}
public static boolean isCharging() {
return sCharging;
}
public static double getLevel() {
return sLevel;
}
public static double getRemainingTime() {
return sRemainingTime;
}
public static void enableNotifications() {
sNotificationsEnabled = true;
}
public static void disableNotifications() {
sNotificationsEnabled = false;
}
public static double[] getCurrentInformation(final Context context) {
if (!getInstance().mIsEnabled) {
getInstance().start(context);
}
return new double[] {getLevel(), isCharging() ? 1.0 : 0.0, getRemainingTime()};
}
}