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/*
* Copyright (C) 2007 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 android.os;
import android.content.Context;
import android.util.Log;
/**
* This class gives you control of the power state of the device.
*
*
* Device battery life will be significantly affected by the use of this API.
* Do not acquire {@link WakeLock}s unless you really need them, use the minimum levels
* possible, and be sure to release them as soon as possible.
*
* You can obtain an instance of this class by calling
* {@link android.content.Context#getSystemService(java.lang.String) Context.getSystemService()}.
*
* The primary API you'll use is {@link #newWakeLock(int, String) newWakeLock()}.
* This will create a {@link PowerManager.WakeLock} object. You can then use methods
* on the wake lock object to control the power state of the device.
*
* In practice it's quite simple:
* {@samplecode
* PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
* PowerManager.WakeLock wl = pm.newWakeLock(PowerManager.SCREEN_DIM_WAKE_LOCK, "My Tag");
* wl.acquire();
* ..screen will stay on during this section..
* wl.release();
* }
*
* The following wake lock levels are defined, with varying effects on system power.
* These levels are mutually exclusive - you may only specify one of them.
*
*
* Flag Value
* CPU Screen Keyboard {@link #PARTIAL_WAKE_LOCK}
* On* Off Off
* {@link #SCREEN_DIM_WAKE_LOCK}
* On Dim Off
* {@link #SCREEN_BRIGHT_WAKE_LOCK}
* On Bright Off
* {@link #FULL_WAKE_LOCK}
* On Bright Bright
*
*
* *If you hold a partial wake lock, the CPU will continue to run, regardless of any
* display timeouts or the state of the screen and even after the user presses the power button.
* In all other wake locks, the CPU will run, but the user can still put the device to sleep
* using the power button.
*
* In addition, you can add two more flags, which affect behavior of the screen only.
* These flags have no effect when combined with a {@link #PARTIAL_WAKE_LOCK}.
*
*
* Flag Value Description {@link #ACQUIRE_CAUSES_WAKEUP}
* Normal wake locks don't actually turn on the illumination. Instead, they cause
* the illumination to remain on once it turns on (e.g. from user activity). This flag
* will force the screen and/or keyboard to turn on immediately, when the WakeLock is
* acquired. A typical use would be for notifications which are important for the user to
* see immediately.
* {@link #ON_AFTER_RELEASE}
* If this flag is set, the user activity timer will be reset when the WakeLock is
* released, causing the illumination to remain on a bit longer. This can be used to
* reduce flicker if you are cycling between wake lock conditions.
*
*
* Any application using a WakeLock must request the {@code android.permission.WAKE_LOCK}
* permission in an {@code <uses-permission>} element of the application's manifest.
*
*/
public final class PowerManager {
private static final String TAG = "PowerManager";
/* NOTE: Wake lock levels were previously defined as a bit field, except that only a few
* combinations were actually supported so the bit field was removed. This explains
* why the numbering scheme is so odd. If adding a new wake lock level, any unused
* value can be used.
*/
/**
* Wake lock level: Ensures that the CPU is running; the screen and keyboard
* backlight will be allowed to go off.
*
* If the user presses the power button, then the screen will be turned off
* but the CPU will be kept on until all partial wake locks have been released.
*
*/
public static final int PARTIAL_WAKE_LOCK = 0x00000001;
/**
* Wake lock level: Ensures that the screen is on (but may be dimmed);
* the keyboard backlight will be allowed to go off.
*
* If the user presses the power button, then the {@link #SCREEN_DIM_WAKE_LOCK} will be
* implicitly released by the system, causing both the screen and the CPU to be turned off.
* Contrast with {@link #PARTIAL_WAKE_LOCK}.
*
*
* @deprecated Most applications should use
* {@link android.view.WindowManager.LayoutParams#FLAG_KEEP_SCREEN_ON} instead
* of this type of wake lock, as it will be correctly managed by the platform
* as the user moves between applications and doesn't require a special permission.
*/
@Deprecated
public static final int SCREEN_DIM_WAKE_LOCK = 0x00000006;
/**
* Wake lock level: Ensures that the screen is on at full brightness;
* the keyboard backlight will be allowed to go off.
*
* If the user presses the power button, then the {@link #SCREEN_BRIGHT_WAKE_LOCK} will be
* implicitly released by the system, causing both the screen and the CPU to be turned off.
* Contrast with {@link #PARTIAL_WAKE_LOCK}.
*
*
* @deprecated Most applications should use
* {@link android.view.WindowManager.LayoutParams#FLAG_KEEP_SCREEN_ON} instead
* of this type of wake lock, as it will be correctly managed by the platform
* as the user moves between applications and doesn't require a special permission.
*/
@Deprecated
public static final int SCREEN_BRIGHT_WAKE_LOCK = 0x0000000a;
/**
* Wake lock level: Ensures that the screen and keyboard backlight are on at
* full brightness.
*
* If the user presses the power button, then the {@link #FULL_WAKE_LOCK} will be
* implicitly released by the system, causing both the screen and the CPU to be turned off.
* Contrast with {@link #PARTIAL_WAKE_LOCK}.
*
*
* @deprecated Most applications should use
* {@link android.view.WindowManager.LayoutParams#FLAG_KEEP_SCREEN_ON} instead
* of this type of wake lock, as it will be correctly managed by the platform
* as the user moves between applications and doesn't require a special permission.
*/
@Deprecated
public static final int FULL_WAKE_LOCK = 0x0000001a;
/**
* Wake lock level: Turns the screen off when the proximity sensor activates.
*
* If the proximity sensor detects that an object is nearby, the screen turns off
* immediately. Shortly after the object moves away, the screen turns on again.
*
* A proximity wake lock does not prevent the device from falling asleep
* unlike {@link #FULL_WAKE_LOCK}, {@link #SCREEN_BRIGHT_WAKE_LOCK} and
* {@link #SCREEN_DIM_WAKE_LOCK}. If there is no user activity and no other
* wake locks are held, then the device will fall asleep (and lock) as usual.
* However, the device will not fall asleep while the screen has been turned off
* by the proximity sensor because it effectively counts as ongoing user activity.
*
* Since not all devices have proximity sensors, use {@link #isWakeLockLevelSupported}
* to determine whether this wake lock level is supported.
*
* Cannot be used with {@link #ACQUIRE_CAUSES_WAKEUP}.
*
*
* {@hide}
*/
public static final int PROXIMITY_SCREEN_OFF_WAKE_LOCK = 0x00000020;
/**
* Mask for the wake lock level component of a combined wake lock level and flags integer.
*
* @hide
*/
public static final int WAKE_LOCK_LEVEL_MASK = 0x0000ffff;
/**
* Wake lock flag: Turn the screen on when the wake lock is acquired.
*
* Normally wake locks don't actually wake the device, they just cause
* the screen to remain on once it's already on. Think of the video player
* application as the normal behavior. Notifications that pop up and want
* the device to be on are the exception; use this flag to be like them.
*
* Cannot be used with {@link #PARTIAL_WAKE_LOCK}.
*
*/
public static final int ACQUIRE_CAUSES_WAKEUP = 0x10000000;
/**
* Wake lock flag: When this wake lock is released, poke the user activity timer
* so the screen stays on for a little longer.
*
* Will not turn the screen on if it is not already on.
* See {@link #ACQUIRE_CAUSES_WAKEUP} if you want that.
*
* Cannot be used with {@link #PARTIAL_WAKE_LOCK}.
*
*/
public static final int ON_AFTER_RELEASE = 0x20000000;
/**
* Flag for {@link WakeLock#release release(int)} to defer releasing a
* {@link #PROXIMITY_SCREEN_OFF_WAKE_LOCK} wake lock until the proximity sensor returns
* a negative value.
*
* {@hide}
*/
public static final int WAIT_FOR_PROXIMITY_NEGATIVE = 1;
/**
* Brightness value for fully on.
* @hide
*/
public static final int BRIGHTNESS_ON = 255;
/**
* Brightness value for fully off.
* @hide
*/
public static final int BRIGHTNESS_OFF = 0;
// Note: Be sure to update android.os.BatteryStats and PowerManager.h
// if adding or modifying user activity event constants.
/**
* User activity event type: Unspecified event type.
* @hide
*/
public static final int USER_ACTIVITY_EVENT_OTHER = 0;
/**
* User activity event type: Button or key pressed or released.
* @hide
*/
public static final int USER_ACTIVITY_EVENT_BUTTON = 1;
/**
* User activity event type: Touch down, move or up.
* @hide
*/
public static final int USER_ACTIVITY_EVENT_TOUCH = 2;
/**
* User activity flag: Do not restart the user activity timeout or brighten
* the display in response to user activity if it is already dimmed.
* @hide
*/
public static final int USER_ACTIVITY_FLAG_NO_CHANGE_LIGHTS = 1 << 0;
/**
* Go to sleep reason code: Going to sleep due by user request.
* @hide
*/
public static final int GO_TO_SLEEP_REASON_USER = 0;
/**
* Go to sleep reason code: Going to sleep due by request of the
* device administration policy.
* @hide
*/
public static final int GO_TO_SLEEP_REASON_DEVICE_ADMIN = 1;
/**
* Go to sleep reason code: Going to sleep due to a screen timeout.
* @hide
*/
public static final int GO_TO_SLEEP_REASON_TIMEOUT = 2;
final Context mContext;
final IPowerManager mService;
final Handler mHandler;
/**
* {@hide}
*/
public PowerManager(Context context, IPowerManager service, Handler handler) {
mContext = context;
mService = service;
mHandler = handler;
}
/**
* Gets the minimum supported screen brightness setting.
* The screen may be allowed to become dimmer than this value but
* this is the minimum value that can be set by the user.
* @hide
*/
public int getMinimumScreenBrightnessSetting() {
return mContext.getResources().getInteger(
com.android.internal.R.integer.config_screenBrightnessSettingMinimum);
}
/**
* Gets the maximum supported screen brightness setting.
* The screen may be allowed to become dimmer than this value but
* this is the maximum value that can be set by the user.
* @hide
*/
public int getMaximumScreenBrightnessSetting() {
return mContext.getResources().getInteger(
com.android.internal.R.integer.config_screenBrightnessSettingMaximum);
}
/**
* Gets the default screen brightness setting.
* @hide
*/
public int getDefaultScreenBrightnessSetting() {
return mContext.getResources().getInteger(
com.android.internal.R.integer.config_screenBrightnessSettingDefault);
}
/**
* Returns true if the screen auto-brightness adjustment setting should
* be available in the UI. This setting is experimental and disabled by default.
* @hide
*/
public static boolean useScreenAutoBrightnessAdjustmentFeature() {
return SystemProperties.getBoolean("persist.power.useautobrightadj", false);
}
/**
* Returns true if the twilight service should be used to adjust screen brightness
* policy. This setting is experimental and disabled by default.
* @hide
*/
public static boolean useTwilightAdjustmentFeature() {
return SystemProperties.getBoolean("persist.power.usetwilightadj", false);
}
/**
* Creates a new wake lock with the specified level and flags.
*
* The {@code levelAndFlags} parameter specifies a wake lock level and optional flags
* combined using the logical OR operator.
*
* The wake lock levels are: {@link #PARTIAL_WAKE_LOCK},
* {@link #FULL_WAKE_LOCK}, {@link #SCREEN_DIM_WAKE_LOCK}
* and {@link #SCREEN_BRIGHT_WAKE_LOCK}. Exactly one wake lock level must be
* specified as part of the {@code levelAndFlags} parameter.
*
* The wake lock flags are: {@link #ACQUIRE_CAUSES_WAKEUP}
* and {@link #ON_AFTER_RELEASE}. Multiple flags can be combined as part of the
* {@code levelAndFlags} parameters.
*
* Call {@link WakeLock#acquire() acquire()} on the object to acquire the
* wake lock, and {@link WakeLock#release release()} when you are done.
*
* {@samplecode
* PowerManager pm = (PowerManager)mContext.getSystemService(
* Context.POWER_SERVICE);
* PowerManager.WakeLock wl = pm.newWakeLock(
* PowerManager.SCREEN_DIM_WAKE_LOCK
* | PowerManager.ON_AFTER_RELEASE,
* TAG);
* wl.acquire();
* // ... do work...
* wl.release();
* }
*
* Although a wake lock can be created without special permissions,
* the {@link android.Manifest.permission#WAKE_LOCK} permission is
* required to actually acquire or release the wake lock that is returned.
*
* If using this to keep the screen on, you should strongly consider using
* {@link android.view.WindowManager.LayoutParams#FLAG_KEEP_SCREEN_ON} instead.
* This window flag will be correctly managed by the platform
* as the user moves between applications and doesn't require a special permission.
*
*
* @param levelAndFlags Combination of wake lock level and flag values defining
* the requested behavior of the WakeLock.
* @param tag Your class name (or other tag) for debugging purposes.
*
* @see WakeLock#acquire()
* @see WakeLock#release()
* @see #PARTIAL_WAKE_LOCK
* @see #FULL_WAKE_LOCK
* @see #SCREEN_DIM_WAKE_LOCK
* @see #SCREEN_BRIGHT_WAKE_LOCK
* @see #ACQUIRE_CAUSES_WAKEUP
* @see #ON_AFTER_RELEASE
*/
public WakeLock newWakeLock(int levelAndFlags, String tag) {
validateWakeLockParameters(levelAndFlags, tag);
return new WakeLock(levelAndFlags, tag, mContext.getOpPackageName());
}
/** @hide */
public static void validateWakeLockParameters(int levelAndFlags, String tag) {
switch (levelAndFlags & WAKE_LOCK_LEVEL_MASK) {
case PARTIAL_WAKE_LOCK:
case SCREEN_DIM_WAKE_LOCK:
case SCREEN_BRIGHT_WAKE_LOCK:
case FULL_WAKE_LOCK:
case PROXIMITY_SCREEN_OFF_WAKE_LOCK:
break;
default:
throw new IllegalArgumentException("Must specify a valid wake lock level.");
}
if (tag == null) {
throw new IllegalArgumentException("The tag must not be null.");
}
}
/**
* Notifies the power manager that user activity happened.
*
* Resets the auto-off timer and brightens the screen if the device
* is not asleep. This is what happens normally when a key or the touch
* screen is pressed or when some other user activity occurs.
* This method does not wake up the device if it has been put to sleep.
*
* Requires the {@link android.Manifest.permission#DEVICE_POWER} permission.
*
*
* @param when The time of the user activity, in the {@link SystemClock#uptimeMillis()}
* time base. This timestamp is used to correctly order the user activity request with
* other power management functions. It should be set
* to the timestamp of the input event that caused the user activity.
* @param noChangeLights If true, does not cause the keyboard backlight to turn on
* because of this event. This is set when the power key is pressed.
* We want the device to stay on while the button is down, but we're about
* to turn off the screen so we don't want the keyboard backlight to turn on again.
* Otherwise the lights flash on and then off and it looks weird.
*
* @see #wakeUp
* @see #goToSleep
*/
public void userActivity(long when, boolean noChangeLights) {
try {
mService.userActivity(when, USER_ACTIVITY_EVENT_OTHER,
noChangeLights ? USER_ACTIVITY_FLAG_NO_CHANGE_LIGHTS : 0);
} catch (RemoteException e) {
}
}
/**
* Forces the device to go to sleep.
*
* Overrides all the wake locks that are held.
* This is what happens when the power key is pressed to turn off the screen.
*
* Requires the {@link android.Manifest.permission#DEVICE_POWER} permission.
*
*
* @param time The time when the request to go to sleep was issued, in the
* {@link SystemClock#uptimeMillis()} time base. This timestamp is used to correctly
* order the go to sleep request with other power management functions. It should be set
* to the timestamp of the input event that caused the request to go to sleep.
*
* @see #userActivity
* @see #wakeUp
*/
public void goToSleep(long time) {
try {
mService.goToSleep(time, GO_TO_SLEEP_REASON_USER);
} catch (RemoteException e) {
}
}
/**
* Forces the device to wake up from sleep.
*
* If the device is currently asleep, wakes it up, otherwise does nothing.
* This is what happens when the power key is pressed to turn on the screen.
*
* Requires the {@link android.Manifest.permission#DEVICE_POWER} permission.
*
*
* @param time The time when the request to wake up was issued, in the
* {@link SystemClock#uptimeMillis()} time base. This timestamp is used to correctly
* order the wake up request with other power management functions. It should be set
* to the timestamp of the input event that caused the request to wake up.
*
* @see #userActivity
* @see #goToSleep
*/
public void wakeUp(long time) {
try {
mService.wakeUp(time);
} catch (RemoteException e) {
}
}
/**
* Forces the device to start napping.
*
* If the device is currently awake, starts dreaming, otherwise does nothing.
* When the dream ends or if the dream cannot be started, the device will
* either wake up or go to sleep depending on whether there has been recent
* user activity.
*
* Requires the {@link android.Manifest.permission#DEVICE_POWER} permission.
*
*
* @param time The time when the request to nap was issued, in the
* {@link SystemClock#uptimeMillis()} time base. This timestamp is used to correctly
* order the nap request with other power management functions. It should be set
* to the timestamp of the input event that caused the request to nap.
*
* @see #wakeUp
* @see #goToSleep
*
* @hide
*/
public void nap(long time) {
try {
mService.nap(time);
} catch (RemoteException e) {
}
}
/**
* Sets the brightness of the backlights (screen, keyboard, button).
*
* Requires the {@link android.Manifest.permission#DEVICE_POWER} permission.
*
*
* @param brightness The brightness value from 0 to 255.
*
* {@hide}
*/
public void setBacklightBrightness(int brightness) {
try {
mService.setTemporaryScreenBrightnessSettingOverride(brightness);
} catch (RemoteException e) {
}
}
/**
* Returns true if the specified wake lock level is supported.
*
* @param level The wake lock level to check.
* @return True if the specified wake lock level is supported.
*
* {@hide}
*/
public boolean isWakeLockLevelSupported(int level) {
try {
return mService.isWakeLockLevelSupported(level);
} catch (RemoteException e) {
return false;
}
}
/**
* Returns whether the screen is currently on.
*
* Only indicates whether the screen is on. The screen could be either bright or dim.
*
* {@samplecode
* PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
* boolean isScreenOn = pm.isScreenOn();
* }
*
*
* @return whether the screen is on (bright or dim).
*/
public boolean isScreenOn() {
try {
return mService.isScreenOn();
} catch (RemoteException e) {
return false;
}
}
/**
* Reboot the device. Will not return if the reboot is successful.
*
* Requires the {@link android.Manifest.permission#REBOOT} permission.
*
*
* @param reason code to pass to the kernel (e.g., "recovery") to
* request special boot modes, or null.
*/
public void reboot(String reason) {
try {
mService.reboot(false, reason, true);
} catch (RemoteException e) {
}
}
/**
* A wake lock is a mechanism to indicate that your application needs
* to have the device stay on.
*
* Any application using a WakeLock must request the {@code android.permission.WAKE_LOCK}
* permission in an {@code <uses-permission>} element of the application's manifest.
* Obtain a wake lock by calling {@link PowerManager#newWakeLock(int, String)}.
*
* Call {@link #acquire()} to acquire the wake lock and force the device to stay
* on at the level that was requested when the wake lock was created.
*
* Call {@link #release()} when you are done and don't need the lock anymore.
* It is very important to do this as soon as possible to avoid running down the
* device's battery excessively.
*
*/
public final class WakeLock {
private final int mFlags;
private final String mTag;
private final String mPackageName;
private final IBinder mToken;
private int mCount;
private boolean mRefCounted = true;
private boolean mHeld;
private WorkSource mWorkSource;
private final Runnable mReleaser = new Runnable() {
public void run() {
release();
}
};
WakeLock(int flags, String tag, String packageName) {
mFlags = flags;
mTag = tag;
mPackageName = packageName;
mToken = new Binder();
}
@Override
protected void finalize() throws Throwable {
synchronized (mToken) {
if (mHeld) {
Log.wtf(TAG, "WakeLock finalized while still held: " + mTag);
try {
mService.releaseWakeLock(mToken, 0);
} catch (RemoteException e) {
}
}
}
}
/**
* Sets whether this WakeLock is reference counted.
*
* Wake locks are reference counted by default. If a wake lock is
* reference counted, then each call to {@link #acquire()} must be
* balanced by an equal number of calls to {@link #release()}. If a wake
* lock is not reference counted, then one call to {@link #release()} is
* sufficient to undo the effect of all previous calls to {@link #acquire()}.
*
*
* @param value True to make the wake lock reference counted, false to
* make the wake lock non-reference counted.
*/
public void setReferenceCounted(boolean value) {
synchronized (mToken) {
mRefCounted = value;
}
}
/**
* Acquires the wake lock.
*
* Ensures that the device is on at the level requested when
* the wake lock was created.
*
*/
public void acquire() {
synchronized (mToken) {
acquireLocked();
}
}
/**
* Acquires the wake lock with a timeout.
*
* Ensures that the device is on at the level requested when
* the wake lock was created. The lock will be released after the given timeout
* expires.
*
*
* @param timeout The timeout after which to release the wake lock, in milliseconds.
*/
public void acquire(long timeout) {
synchronized (mToken) {
acquireLocked();
mHandler.postDelayed(mReleaser, timeout);
}
}
private void acquireLocked() {
if (!mRefCounted || mCount++ == 0) {
// Do this even if the wake lock is already thought to be held (mHeld == true)
// because non-reference counted wake locks are not always properly released.
// For example, the keyguard's wake lock might be forcibly released by the
// power manager without the keyguard knowing. A subsequent call to acquire
// should immediately acquire the wake lock once again despite never having
// been explicitly released by the keyguard.
mHandler.removeCallbacks(mReleaser);
try {
mService.acquireWakeLock(mToken, mFlags, mTag, mPackageName, mWorkSource);
} catch (RemoteException e) {
}
mHeld = true;
}
}
/**
* Releases the wake lock.
*
* This method releases your claim to the CPU or screen being on.
* The screen may turn off shortly after you release the wake lock, or it may
* not if there are other wake locks still held.
*
*/
public void release() {
release(0);
}
/**
* Releases the wake lock with flags to modify the release behavior.
*
* This method releases your claim to the CPU or screen being on.
* The screen may turn off shortly after you release the wake lock, or it may
* not if there are other wake locks still held.
*
*
* @param flags Combination of flag values to modify the release behavior.
* Currently only {@link #WAIT_FOR_PROXIMITY_NEGATIVE} is supported.
*
* {@hide}
*/
public void release(int flags) {
synchronized (mToken) {
if (!mRefCounted || --mCount == 0) {
mHandler.removeCallbacks(mReleaser);
if (mHeld) {
try {
mService.releaseWakeLock(mToken, flags);
} catch (RemoteException e) {
}
mHeld = false;
}
}
if (mCount < 0) {
throw new RuntimeException("WakeLock under-locked " + mTag);
}
}
}
/**
* Returns true if the wake lock has been acquired but not yet released.
*
* @return True if the wake lock is held.
*/
public boolean isHeld() {
synchronized (mToken) {
return mHeld;
}
}
/**
* Sets the work source associated with the wake lock.
*
* The work source is used to determine on behalf of which application
* the wake lock is being held. This is useful in the case where a
* service is performing work on behalf of an application so that the
* cost of that work can be accounted to the application.
*
*
* @param ws The work source, or null if none.
*/
public void setWorkSource(WorkSource ws) {
synchronized (mToken) {
if (ws != null && ws.size() == 0) {
ws = null;
}
final boolean changed;
if (ws == null) {
changed = mWorkSource != null;
mWorkSource = null;
} else if (mWorkSource == null) {
changed = true;
mWorkSource = new WorkSource(ws);
} else {
changed = mWorkSource.diff(ws);
if (changed) {
mWorkSource.set(ws);
}
}
if (changed && mHeld) {
try {
mService.updateWakeLockWorkSource(mToken, mWorkSource);
} catch (RemoteException e) {
}
}
}
}
@Override
public String toString() {
synchronized (mToken) {
return "WakeLock{"
+ Integer.toHexString(System.identityHashCode(this))
+ " held=" + mHeld + ", refCount=" + mCount + "}";
}
}
}
}