android.os
public class
public class
android.os.PowerManager
| java.lang.Object | ||
| android.os.PowerManager | ||
Class that lets you control the power state of the device. Get an instance of this class by calling Context.getSystemService().
Nested Classes
| PowerManager.WakeLock | Class lets you say that you need to have the device on. |
Summary
Constants
| Value | ||||
|---|---|---|---|---|
| int | ACQUIRE_CAUSES_WAKEUP | Normally wake locks don't actually wake the device, they just cause it to remain on once it's already on. | 268435456 | 0x10000000 |
| int | FULL_WAKE_LOCK | Wake lock that ensures that the screen and keyboard are on at full brightness. | 2 | 0x00000002 |
| int | ON_AFTER_RELEASE | When this wake lock is released, poke the user activity timer so the screen stays on for a little longer. | 536870912 | 0x20000000 |
| int | PARTIAL_WAKE_LOCK | Wake lock that ensures that the CPU is running. | 1 | 0x00000001 |
| int | SCREEN_BRIGHT_WAKE_LOCK | Wake lock that ensures that the screen is on at full brightness; the keyboard backlight will be allowed to go off. | 3 | 0x00000003 |
| int | SCREEN_DIM_WAKE_LOCK | Wake lock that ensures that the screen is on, but the keyboard backlight will be allowed to go off, and the screen backlight will be allowed to go dim. | 4 | 0x00000004 |
Public Methods
| void | goToSleep(long time) | ||||
| Force the device to go to sleep. | |||||
| WakeLock | newWakeLock(int flags, String tag) | ||||
| Get a wake lock at the level of the flags parameter. | |||||
| void | userActivity(long when, boolean noChangeLights) | ||||
| User activity happened. | |||||
Methods inherited
from class
java.lang.Object
Details
Constants
public static final int ACQUIRE_CAUSES_WAKEUP
Normally wake locks don't actually wake the device, they just cause
it to remain on once it's already on. Think of the video player
app 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.
Does not work with PARTIAL_WAKE_LOCKs.
Constant Value:
268435456
(0x10000000)
public static final int FULL_WAKE_LOCK
Wake lock that ensures that the screen and keyboard are on at
full brightness.
Constant Value:
2
(0x00000002)
public static final int ON_AFTER_RELEASE
When this wake lock is released, poke the user activity timer
so the screen stays on for a little longer.
Does not work with PARTIAL_WAKE_LOCKs.
Constant Value:
536870912
(0x20000000)
public static final int PARTIAL_WAKE_LOCK
Wake lock that ensures that the CPU is running. The screen might
not be on.
Constant Value:
1
(0x00000001)
public static final int SCREEN_BRIGHT_WAKE_LOCK
Wake lock that ensures that the screen is on at full brightness;
the keyboard backlight will be allowed to go off.
Constant Value:
3
(0x00000003)
public static final int SCREEN_DIM_WAKE_LOCK
Wake lock that ensures that the screen is on, but the keyboard
backlight will be allowed to go off, and the screen backlight
will be allowed to go dim.
Constant Value:
4
(0x00000004)
Public Methods
public void goToSleep(long time)
Force the device to go to sleep. Overrides all the wake locks that are
held.
Parameters
| time | is used to order this correctly with the wake lock calls. The time should be in the SystemClock.uptimeMillis() time base. |
|---|
public WakeLock newWakeLock(int flags, String tag)
Get a wake lock at the level of the flags parameter. Call
acquire() on the object to acquire the
wake lock, and release() when you are done.
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();
// ...
wl.release();
Parameters
| flags | PARTIAL_WAKE_LOCK or FULL_WAKE_LOCK |
|---|---|
| tag | Your class name (or other tag) for debugging purposes. |
See Also
public void userActivity(long when, boolean noChangeLights)
User activity happened.
Turns the device from whatever state it's in to full on, and resets the auto-off timer.
Parameters
| when | is used to order this correctly with the wake lock calls. This time should be in the SystemClock.uptimeMillis() time base. |
|---|---|
| noChangeLights | should be true if you don't want the lights to turn on because of this event. This is set when the power key goes down. We want the device to stay on while the button is down, but we're about to turn off. Otherwise the lights flash on and then off and it looks weird. |