PowerManager.java revision 0a571123544058578b4ef1558c276a4050519652
1/* 2 * Copyright (C) 2007 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17package android.os; 18 19import android.annotation.SdkConstant; 20import android.annotation.SystemApi; 21import android.content.Context; 22import android.util.Log; 23 24/** 25 * This class gives you control of the power state of the device. 26 * 27 * <p> 28 * <b>Device battery life will be significantly affected by the use of this API.</b> 29 * Do not acquire {@link WakeLock}s unless you really need them, use the minimum levels 30 * possible, and be sure to release them as soon as possible. 31 * </p><p> 32 * You can obtain an instance of this class by calling 33 * {@link android.content.Context#getSystemService(java.lang.String) Context.getSystemService()}. 34 * </p><p> 35 * The primary API you'll use is {@link #newWakeLock(int, String) newWakeLock()}. 36 * This will create a {@link PowerManager.WakeLock} object. You can then use methods 37 * on the wake lock object to control the power state of the device. 38 * </p><p> 39 * In practice it's quite simple: 40 * {@samplecode 41 * PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE); 42 * PowerManager.WakeLock wl = pm.newWakeLock(PowerManager.SCREEN_DIM_WAKE_LOCK, "My Tag"); 43 * wl.acquire(); 44 * ..screen will stay on during this section.. 45 * wl.release(); 46 * } 47 * </p><p> 48 * The following wake lock levels are defined, with varying effects on system power. 49 * <i>These levels are mutually exclusive - you may only specify one of them.</i> 50 * 51 * <table> 52 * <tr><th>Flag Value</th> 53 * <th>CPU</th> <th>Screen</th> <th>Keyboard</th></tr> 54 * 55 * <tr><td>{@link #PARTIAL_WAKE_LOCK}</td> 56 * <td>On*</td> <td>Off</td> <td>Off</td> 57 * </tr> 58 * 59 * <tr><td>{@link #SCREEN_DIM_WAKE_LOCK}</td> 60 * <td>On</td> <td>Dim</td> <td>Off</td> 61 * </tr> 62 * 63 * <tr><td>{@link #SCREEN_BRIGHT_WAKE_LOCK}</td> 64 * <td>On</td> <td>Bright</td> <td>Off</td> 65 * </tr> 66 * 67 * <tr><td>{@link #FULL_WAKE_LOCK}</td> 68 * <td>On</td> <td>Bright</td> <td>Bright</td> 69 * </tr> 70 * </table> 71 * </p><p> 72 * *<i>If you hold a partial wake lock, the CPU will continue to run, regardless of any 73 * display timeouts or the state of the screen and even after the user presses the power button. 74 * In all other wake locks, the CPU will run, but the user can still put the device to sleep 75 * using the power button.</i> 76 * </p><p> 77 * In addition, you can add two more flags, which affect behavior of the screen only. 78 * <i>These flags have no effect when combined with a {@link #PARTIAL_WAKE_LOCK}.</i></p> 79 * 80 * <table> 81 * <tr><th>Flag Value</th> <th>Description</th></tr> 82 * 83 * <tr><td>{@link #ACQUIRE_CAUSES_WAKEUP}</td> 84 * <td>Normal wake locks don't actually turn on the illumination. Instead, they cause 85 * the illumination to remain on once it turns on (e.g. from user activity). This flag 86 * will force the screen and/or keyboard to turn on immediately, when the WakeLock is 87 * acquired. A typical use would be for notifications which are important for the user to 88 * see immediately.</td> 89 * </tr> 90 * 91 * <tr><td>{@link #ON_AFTER_RELEASE}</td> 92 * <td>If this flag is set, the user activity timer will be reset when the WakeLock is 93 * released, causing the illumination to remain on a bit longer. This can be used to 94 * reduce flicker if you are cycling between wake lock conditions.</td> 95 * </tr> 96 * </table> 97 * <p> 98 * Any application using a WakeLock must request the {@code android.permission.WAKE_LOCK} 99 * permission in an {@code <uses-permission>} element of the application's manifest. 100 * </p> 101 */ 102public final class PowerManager { 103 private static final String TAG = "PowerManager"; 104 105 /* NOTE: Wake lock levels were previously defined as a bit field, except that only a few 106 * combinations were actually supported so the bit field was removed. This explains 107 * why the numbering scheme is so odd. If adding a new wake lock level, any unused 108 * value can be used. 109 */ 110 111 /** 112 * Wake lock level: Ensures that the CPU is running; the screen and keyboard 113 * backlight will be allowed to go off. 114 * <p> 115 * If the user presses the power button, then the screen will be turned off 116 * but the CPU will be kept on until all partial wake locks have been released. 117 * </p> 118 */ 119 public static final int PARTIAL_WAKE_LOCK = 0x00000001; 120 121 /** 122 * Wake lock level: Ensures that the screen is on (but may be dimmed); 123 * the keyboard backlight will be allowed to go off. 124 * <p> 125 * If the user presses the power button, then the {@link #SCREEN_DIM_WAKE_LOCK} will be 126 * implicitly released by the system, causing both the screen and the CPU to be turned off. 127 * Contrast with {@link #PARTIAL_WAKE_LOCK}. 128 * </p> 129 * 130 * @deprecated Most applications should use 131 * {@link android.view.WindowManager.LayoutParams#FLAG_KEEP_SCREEN_ON} instead 132 * of this type of wake lock, as it will be correctly managed by the platform 133 * as the user moves between applications and doesn't require a special permission. 134 */ 135 @Deprecated 136 public static final int SCREEN_DIM_WAKE_LOCK = 0x00000006; 137 138 /** 139 * Wake lock level: Ensures that the screen is on at full brightness; 140 * the keyboard backlight will be allowed to go off. 141 * <p> 142 * If the user presses the power button, then the {@link #SCREEN_BRIGHT_WAKE_LOCK} will be 143 * implicitly released by the system, causing both the screen and the CPU to be turned off. 144 * Contrast with {@link #PARTIAL_WAKE_LOCK}. 145 * </p> 146 * 147 * @deprecated Most applications should use 148 * {@link android.view.WindowManager.LayoutParams#FLAG_KEEP_SCREEN_ON} instead 149 * of this type of wake lock, as it will be correctly managed by the platform 150 * as the user moves between applications and doesn't require a special permission. 151 */ 152 @Deprecated 153 public static final int SCREEN_BRIGHT_WAKE_LOCK = 0x0000000a; 154 155 /** 156 * Wake lock level: Ensures that the screen and keyboard backlight are on at 157 * full brightness. 158 * <p> 159 * If the user presses the power button, then the {@link #FULL_WAKE_LOCK} will be 160 * implicitly released by the system, causing both the screen and the CPU to be turned off. 161 * Contrast with {@link #PARTIAL_WAKE_LOCK}. 162 * </p> 163 * 164 * @deprecated Most applications should use 165 * {@link android.view.WindowManager.LayoutParams#FLAG_KEEP_SCREEN_ON} instead 166 * of this type of wake lock, as it will be correctly managed by the platform 167 * as the user moves between applications and doesn't require a special permission. 168 */ 169 @Deprecated 170 public static final int FULL_WAKE_LOCK = 0x0000001a; 171 172 /** 173 * Wake lock level: Turns the screen off when the proximity sensor activates. 174 * <p> 175 * If the proximity sensor detects that an object is nearby, the screen turns off 176 * immediately. Shortly after the object moves away, the screen turns on again. 177 * </p><p> 178 * A proximity wake lock does not prevent the device from falling asleep 179 * unlike {@link #FULL_WAKE_LOCK}, {@link #SCREEN_BRIGHT_WAKE_LOCK} and 180 * {@link #SCREEN_DIM_WAKE_LOCK}. If there is no user activity and no other 181 * wake locks are held, then the device will fall asleep (and lock) as usual. 182 * However, the device will not fall asleep while the screen has been turned off 183 * by the proximity sensor because it effectively counts as ongoing user activity. 184 * </p><p> 185 * Since not all devices have proximity sensors, use {@link #isWakeLockLevelSupported} 186 * to determine whether this wake lock level is supported. 187 * </p><p> 188 * Cannot be used with {@link #ACQUIRE_CAUSES_WAKEUP}. 189 * </p> 190 */ 191 public static final int PROXIMITY_SCREEN_OFF_WAKE_LOCK = 0x00000020; 192 193 /** 194 * Wake lock level: Put the screen in a low power state and allow the CPU to suspend 195 * if no other wake locks are held. 196 * <p> 197 * This is used by the dream manager to implement doze mode. It currently 198 * has no effect unless the power manager is in the dozing state. 199 * </p><p> 200 * Requires the {@link android.Manifest.permission#DEVICE_POWER} permission. 201 * </p> 202 * 203 * {@hide} 204 */ 205 public static final int DOZE_WAKE_LOCK = 0x00000040; 206 207 /** 208 * Mask for the wake lock level component of a combined wake lock level and flags integer. 209 * 210 * @hide 211 */ 212 public static final int WAKE_LOCK_LEVEL_MASK = 0x0000ffff; 213 214 /** 215 * Wake lock flag: Turn the screen on when the wake lock is acquired. 216 * <p> 217 * Normally wake locks don't actually wake the device, they just cause 218 * the screen to remain on once it's already on. Think of the video player 219 * application as the normal behavior. Notifications that pop up and want 220 * the device to be on are the exception; use this flag to be like them. 221 * </p><p> 222 * Cannot be used with {@link #PARTIAL_WAKE_LOCK}. 223 * </p> 224 */ 225 public static final int ACQUIRE_CAUSES_WAKEUP = 0x10000000; 226 227 /** 228 * Wake lock flag: When this wake lock is released, poke the user activity timer 229 * so the screen stays on for a little longer. 230 * <p> 231 * Will not turn the screen on if it is not already on. 232 * See {@link #ACQUIRE_CAUSES_WAKEUP} if you want that. 233 * </p><p> 234 * Cannot be used with {@link #PARTIAL_WAKE_LOCK}. 235 * </p> 236 */ 237 public static final int ON_AFTER_RELEASE = 0x20000000; 238 239 /** 240 * Wake lock flag: This wake lock is not important for logging events. If a later 241 * wake lock is acquired that is important, it will be considered the one to log. 242 * @hide 243 */ 244 public static final int UNIMPORTANT_FOR_LOGGING = 0x40000000; 245 246 /** 247 * Flag for {@link WakeLock#release WakeLock.release(int)}: Defer releasing a 248 * {@link #PROXIMITY_SCREEN_OFF_WAKE_LOCK} wake lock until the proximity sensor 249 * indicates that an object is not in close proximity. 250 */ 251 public static final int WAIT_FOR_PROXIMITY_NEGATIVE = 1; 252 253 /** 254 * Brightness value for fully on. 255 * @hide 256 */ 257 public static final int BRIGHTNESS_ON = 255; 258 259 /** 260 * Brightness value for fully off. 261 * @hide 262 */ 263 public static final int BRIGHTNESS_OFF = 0; 264 265 /** 266 * Brightness value for default policy handling by the system. 267 * @hide 268 */ 269 public static final int BRIGHTNESS_DEFAULT = -1; 270 271 // Note: Be sure to update android.os.BatteryStats and PowerManager.h 272 // if adding or modifying user activity event constants. 273 274 /** 275 * User activity event type: Unspecified event type. 276 * @hide 277 */ 278 @SystemApi 279 public static final int USER_ACTIVITY_EVENT_OTHER = 0; 280 281 /** 282 * User activity event type: Button or key pressed or released. 283 * @hide 284 */ 285 @SystemApi 286 public static final int USER_ACTIVITY_EVENT_BUTTON = 1; 287 288 /** 289 * User activity event type: Touch down, move or up. 290 * @hide 291 */ 292 @SystemApi 293 public static final int USER_ACTIVITY_EVENT_TOUCH = 2; 294 295 /** 296 * User activity flag: If already dimmed, extend the dim timeout 297 * but do not brighten. This flag is useful for keeping the screen on 298 * a little longer without causing a visible change such as when 299 * the power key is pressed. 300 * @hide 301 */ 302 @SystemApi 303 public static final int USER_ACTIVITY_FLAG_NO_CHANGE_LIGHTS = 1 << 0; 304 305 /** 306 * User activity flag: Note the user activity as usual but do not 307 * reset the user activity timeout. This flag is useful for applying 308 * user activity power hints when interacting with the device indirectly 309 * on a secondary screen while allowing the primary screen to go to sleep. 310 * @hide 311 */ 312 @SystemApi 313 public static final int USER_ACTIVITY_FLAG_INDIRECT = 1 << 1; 314 315 /** 316 * Go to sleep reason code: Going to sleep due by application request. 317 * @hide 318 */ 319 public static final int GO_TO_SLEEP_REASON_APPLICATION = 0; 320 321 /** 322 * Go to sleep reason code: Going to sleep due by request of the 323 * device administration policy. 324 * @hide 325 */ 326 public static final int GO_TO_SLEEP_REASON_DEVICE_ADMIN = 1; 327 328 /** 329 * Go to sleep reason code: Going to sleep due to a screen timeout. 330 * @hide 331 */ 332 public static final int GO_TO_SLEEP_REASON_TIMEOUT = 2; 333 334 /** 335 * Go to sleep reason code: Going to sleep due to the lid switch being closed. 336 * @hide 337 */ 338 public static final int GO_TO_SLEEP_REASON_LID_SWITCH = 3; 339 340 /** 341 * Go to sleep reason code: Going to sleep due to the power button being pressed. 342 * @hide 343 */ 344 public static final int GO_TO_SLEEP_REASON_POWER_BUTTON = 4; 345 346 /** 347 * Go to sleep reason code: Going to sleep due to HDMI. 348 * @hide 349 */ 350 public static final int GO_TO_SLEEP_REASON_HDMI = 5; 351 352 /** 353 * Go to sleep flag: Skip dozing state and directly go to full sleep. 354 * @hide 355 */ 356 public static final int GO_TO_SLEEP_FLAG_NO_DOZE = 1 << 0; 357 358 /** 359 * The value to pass as the 'reason' argument to reboot() to 360 * reboot into recovery mode (for applying system updates, doing 361 * factory resets, etc.). 362 * <p> 363 * Requires the {@link android.Manifest.permission#RECOVERY} 364 * permission (in addition to 365 * {@link android.Manifest.permission#REBOOT}). 366 * </p> 367 * @hide 368 */ 369 public static final String REBOOT_RECOVERY = "recovery"; 370 371 final Context mContext; 372 final IPowerManager mService; 373 final Handler mHandler; 374 375 /** 376 * {@hide} 377 */ 378 public PowerManager(Context context, IPowerManager service, Handler handler) { 379 mContext = context; 380 mService = service; 381 mHandler = handler; 382 } 383 384 /** 385 * Gets the minimum supported screen brightness setting. 386 * The screen may be allowed to become dimmer than this value but 387 * this is the minimum value that can be set by the user. 388 * @hide 389 */ 390 public int getMinimumScreenBrightnessSetting() { 391 return mContext.getResources().getInteger( 392 com.android.internal.R.integer.config_screenBrightnessSettingMinimum); 393 } 394 395 /** 396 * Gets the maximum supported screen brightness setting. 397 * The screen may be allowed to become dimmer than this value but 398 * this is the maximum value that can be set by the user. 399 * @hide 400 */ 401 public int getMaximumScreenBrightnessSetting() { 402 return mContext.getResources().getInteger( 403 com.android.internal.R.integer.config_screenBrightnessSettingMaximum); 404 } 405 406 /** 407 * Gets the default screen brightness setting. 408 * @hide 409 */ 410 public int getDefaultScreenBrightnessSetting() { 411 return mContext.getResources().getInteger( 412 com.android.internal.R.integer.config_screenBrightnessSettingDefault); 413 } 414 415 /** 416 * Returns true if the twilight service should be used to adjust screen brightness 417 * policy. This setting is experimental and disabled by default. 418 * @hide 419 */ 420 public static boolean useTwilightAdjustmentFeature() { 421 return SystemProperties.getBoolean("persist.power.usetwilightadj", false); 422 } 423 424 /** 425 * Creates a new wake lock with the specified level and flags. 426 * <p> 427 * The {@code levelAndFlags} parameter specifies a wake lock level and optional flags 428 * combined using the logical OR operator. 429 * </p><p> 430 * The wake lock levels are: {@link #PARTIAL_WAKE_LOCK}, 431 * {@link #FULL_WAKE_LOCK}, {@link #SCREEN_DIM_WAKE_LOCK} 432 * and {@link #SCREEN_BRIGHT_WAKE_LOCK}. Exactly one wake lock level must be 433 * specified as part of the {@code levelAndFlags} parameter. 434 * </p><p> 435 * The wake lock flags are: {@link #ACQUIRE_CAUSES_WAKEUP} 436 * and {@link #ON_AFTER_RELEASE}. Multiple flags can be combined as part of the 437 * {@code levelAndFlags} parameters. 438 * </p><p> 439 * Call {@link WakeLock#acquire() acquire()} on the object to acquire the 440 * wake lock, and {@link WakeLock#release release()} when you are done. 441 * </p><p> 442 * {@samplecode 443 * PowerManager pm = (PowerManager)mContext.getSystemService( 444 * Context.POWER_SERVICE); 445 * PowerManager.WakeLock wl = pm.newWakeLock( 446 * PowerManager.SCREEN_DIM_WAKE_LOCK 447 * | PowerManager.ON_AFTER_RELEASE, 448 * TAG); 449 * wl.acquire(); 450 * // ... do work... 451 * wl.release(); 452 * } 453 * </p><p> 454 * Although a wake lock can be created without special permissions, 455 * the {@link android.Manifest.permission#WAKE_LOCK} permission is 456 * required to actually acquire or release the wake lock that is returned. 457 * </p><p class="note"> 458 * If using this to keep the screen on, you should strongly consider using 459 * {@link android.view.WindowManager.LayoutParams#FLAG_KEEP_SCREEN_ON} instead. 460 * This window flag will be correctly managed by the platform 461 * as the user moves between applications and doesn't require a special permission. 462 * </p> 463 * 464 * @param levelAndFlags Combination of wake lock level and flag values defining 465 * the requested behavior of the WakeLock. 466 * @param tag Your class name (or other tag) for debugging purposes. 467 * 468 * @see WakeLock#acquire() 469 * @see WakeLock#release() 470 * @see #PARTIAL_WAKE_LOCK 471 * @see #FULL_WAKE_LOCK 472 * @see #SCREEN_DIM_WAKE_LOCK 473 * @see #SCREEN_BRIGHT_WAKE_LOCK 474 * @see #PROXIMITY_SCREEN_OFF_WAKE_LOCK 475 * @see #ACQUIRE_CAUSES_WAKEUP 476 * @see #ON_AFTER_RELEASE 477 */ 478 public WakeLock newWakeLock(int levelAndFlags, String tag) { 479 validateWakeLockParameters(levelAndFlags, tag); 480 return new WakeLock(levelAndFlags, tag, mContext.getOpPackageName()); 481 } 482 483 /** @hide */ 484 public static void validateWakeLockParameters(int levelAndFlags, String tag) { 485 switch (levelAndFlags & WAKE_LOCK_LEVEL_MASK) { 486 case PARTIAL_WAKE_LOCK: 487 case SCREEN_DIM_WAKE_LOCK: 488 case SCREEN_BRIGHT_WAKE_LOCK: 489 case FULL_WAKE_LOCK: 490 case PROXIMITY_SCREEN_OFF_WAKE_LOCK: 491 case DOZE_WAKE_LOCK: 492 break; 493 default: 494 throw new IllegalArgumentException("Must specify a valid wake lock level."); 495 } 496 if (tag == null) { 497 throw new IllegalArgumentException("The tag must not be null."); 498 } 499 } 500 501 /** 502 * Notifies the power manager that user activity happened. 503 * <p> 504 * Resets the auto-off timer and brightens the screen if the device 505 * is not asleep. This is what happens normally when a key or the touch 506 * screen is pressed or when some other user activity occurs. 507 * This method does not wake up the device if it has been put to sleep. 508 * </p><p> 509 * Requires the {@link android.Manifest.permission#DEVICE_POWER} permission. 510 * </p> 511 * 512 * @param when The time of the user activity, in the {@link SystemClock#uptimeMillis()} 513 * time base. This timestamp is used to correctly order the user activity request with 514 * other power management functions. It should be set 515 * to the timestamp of the input event that caused the user activity. 516 * @param noChangeLights If true, does not cause the keyboard backlight to turn on 517 * because of this event. This is set when the power key is pressed. 518 * We want the device to stay on while the button is down, but we're about 519 * to turn off the screen so we don't want the keyboard backlight to turn on again. 520 * Otherwise the lights flash on and then off and it looks weird. 521 * 522 * @see #wakeUp 523 * @see #goToSleep 524 */ 525 public void userActivity(long when, boolean noChangeLights) { 526 userActivity(when, USER_ACTIVITY_EVENT_OTHER, 527 noChangeLights ? USER_ACTIVITY_FLAG_NO_CHANGE_LIGHTS : 0); 528 } 529 530 /** 531 * Notifies the power manager that user activity happened. 532 * <p> 533 * Resets the auto-off timer and brightens the screen if the device 534 * is not asleep. This is what happens normally when a key or the touch 535 * screen is pressed or when some other user activity occurs. 536 * This method does not wake up the device if it has been put to sleep. 537 * </p><p> 538 * Requires the {@link android.Manifest.permission#DEVICE_POWER} or 539 * {@link android.Manifest.permission#USER_ACTIVITY} permission. 540 * </p> 541 * 542 * @param when The time of the user activity, in the {@link SystemClock#uptimeMillis()} 543 * time base. This timestamp is used to correctly order the user activity request with 544 * other power management functions. It should be set 545 * to the timestamp of the input event that caused the user activity. 546 * @param event The user activity event. 547 * @param flags Optional user activity flags. 548 * 549 * @see #wakeUp 550 * @see #goToSleep 551 * 552 * @hide Requires signature or system permission. 553 */ 554 @SystemApi 555 public void userActivity(long when, int event, int flags) { 556 try { 557 mService.userActivity(when, event, flags); 558 } catch (RemoteException e) { 559 } 560 } 561 562 /** 563 * Forces the device to go to sleep. 564 * <p> 565 * Overrides all the wake locks that are held. 566 * This is what happens when the power key is pressed to turn off the screen. 567 * </p><p> 568 * Requires the {@link android.Manifest.permission#DEVICE_POWER} permission. 569 * </p> 570 * 571 * @param time The time when the request to go to sleep was issued, in the 572 * {@link SystemClock#uptimeMillis()} time base. This timestamp is used to correctly 573 * order the go to sleep request with other power management functions. It should be set 574 * to the timestamp of the input event that caused the request to go to sleep. 575 * 576 * @see #userActivity 577 * @see #wakeUp 578 */ 579 public void goToSleep(long time) { 580 goToSleep(time, GO_TO_SLEEP_REASON_APPLICATION, 0); 581 } 582 583 /** 584 * @hide 585 */ 586 public void goToSleep(long time, int reason, int flags) { 587 try { 588 mService.goToSleep(time, reason, flags); 589 } catch (RemoteException e) { 590 } 591 } 592 593 /** 594 * Forces the device to wake up from sleep. 595 * <p> 596 * If the device is currently asleep, wakes it up, otherwise does nothing. 597 * This is what happens when the power key is pressed to turn on the screen. 598 * </p><p> 599 * Requires the {@link android.Manifest.permission#DEVICE_POWER} permission. 600 * </p> 601 * 602 * @param time The time when the request to wake up was issued, in the 603 * {@link SystemClock#uptimeMillis()} time base. This timestamp is used to correctly 604 * order the wake up request with other power management functions. It should be set 605 * to the timestamp of the input event that caused the request to wake up. 606 * 607 * @see #userActivity 608 * @see #goToSleep 609 */ 610 public void wakeUp(long time) { 611 try { 612 mService.wakeUp(time); 613 } catch (RemoteException e) { 614 } 615 } 616 617 /** 618 * Forces the device to start napping. 619 * <p> 620 * If the device is currently awake, starts dreaming, otherwise does nothing. 621 * When the dream ends or if the dream cannot be started, the device will 622 * either wake up or go to sleep depending on whether there has been recent 623 * user activity. 624 * </p><p> 625 * Requires the {@link android.Manifest.permission#DEVICE_POWER} permission. 626 * </p> 627 * 628 * @param time The time when the request to nap was issued, in the 629 * {@link SystemClock#uptimeMillis()} time base. This timestamp is used to correctly 630 * order the nap request with other power management functions. It should be set 631 * to the timestamp of the input event that caused the request to nap. 632 * 633 * @see #wakeUp 634 * @see #goToSleep 635 * 636 * @hide 637 */ 638 public void nap(long time) { 639 try { 640 mService.nap(time); 641 } catch (RemoteException e) { 642 } 643 } 644 645 /** 646 * Sets the brightness of the backlights (screen, keyboard, button). 647 * <p> 648 * Requires the {@link android.Manifest.permission#DEVICE_POWER} permission. 649 * </p> 650 * 651 * @param brightness The brightness value from 0 to 255. 652 * 653 * {@hide} 654 */ 655 public void setBacklightBrightness(int brightness) { 656 try { 657 mService.setTemporaryScreenBrightnessSettingOverride(brightness); 658 } catch (RemoteException e) { 659 } 660 } 661 662 /** 663 * Returns true if the specified wake lock level is supported. 664 * 665 * @param level The wake lock level to check. 666 * @return True if the specified wake lock level is supported. 667 */ 668 public boolean isWakeLockLevelSupported(int level) { 669 try { 670 return mService.isWakeLockLevelSupported(level); 671 } catch (RemoteException e) { 672 return false; 673 } 674 } 675 676 /** 677 * Returns true if the device is in an interactive state. 678 * <p> 679 * For historical reasons, the name of this method refers to the power state of 680 * the screen but it actually describes the overall interactive state of 681 * the device. This method has been replaced by {@link #isInteractive}. 682 * </p><p> 683 * The value returned by this method only indicates whether the device is 684 * in an interactive state which may have nothing to do with the screen being 685 * on or off. To determine the actual state of the screen, 686 * use {@link android.view.Display#getState}. 687 * </p> 688 * 689 * @return True if the device is in an interactive state. 690 * 691 * @deprecated Use {@link #isInteractive} instead. 692 */ 693 @Deprecated 694 public boolean isScreenOn() { 695 return isInteractive(); 696 } 697 698 /** 699 * Returns true if the device is in an interactive state. 700 * <p> 701 * When this method returns true, the device is awake and ready to interact 702 * with the user (although this is not a guarantee that the user is actively 703 * interacting with the device just this moment). The main screen is usually 704 * turned on while in this state. Certain features, such as the proximity 705 * sensor, may temporarily turn off the screen while still leaving the device in an 706 * interactive state. Note in particular that the device is still considered 707 * to be interactive while dreaming (since dreams can be interactive) but not 708 * when it is dozing or asleep. 709 * </p><p> 710 * When this method returns false, the device is dozing or asleep and must 711 * be awoken before it will become ready to interact with the user again. The 712 * main screen is usually turned off while in this state. Certain features, 713 * such as "ambient mode" may cause the main screen to remain on (albeit in a 714 * low power state) to display system-provided content while the device dozes. 715 * </p><p> 716 * The system will send a {@link android.content.Intent#ACTION_SCREEN_ON screen on} 717 * or {@link android.content.Intent#ACTION_SCREEN_OFF screen off} broadcast 718 * whenever the interactive state of the device changes. For historical reasons, 719 * the names of these broadcasts refer to the power state of the screen 720 * but they are actually sent in response to changes in the overall interactive 721 * state of the device, as described by this method. 722 * </p><p> 723 * Services may use the non-interactive state as a hint to conserve power 724 * since the user is not present. 725 * </p> 726 * 727 * @return True if the device is in an interactive state. 728 * 729 * @see android.content.Intent#ACTION_SCREEN_ON 730 * @see android.content.Intent#ACTION_SCREEN_OFF 731 */ 732 public boolean isInteractive() { 733 try { 734 return mService.isInteractive(); 735 } catch (RemoteException e) { 736 return false; 737 } 738 } 739 740 /** 741 * Reboot the device. Will not return if the reboot is successful. 742 * <p> 743 * Requires the {@link android.Manifest.permission#REBOOT} permission. 744 * </p> 745 * 746 * @param reason code to pass to the kernel (e.g., "recovery") to 747 * request special boot modes, or null. 748 */ 749 public void reboot(String reason) { 750 try { 751 mService.reboot(false, reason, true); 752 } catch (RemoteException e) { 753 } 754 } 755 756 /** 757 * Returns true if the device is currently in power save mode. When in this mode, 758 * applications should reduce their functionality in order to conserve battery as 759 * much as possible. You can monitor for changes to this state with 760 * {@link #ACTION_POWER_SAVE_MODE_CHANGED}. 761 * 762 * @return Returns true if currently in low power mode, else false. 763 */ 764 public boolean isPowerSaveMode() { 765 try { 766 return mService.isPowerSaveMode(); 767 } catch (RemoteException e) { 768 return false; 769 } 770 } 771 772 /** 773 * Intent that is broadcast when the state of {@link #isPowerSaveMode()} changes. 774 * This broadcast is only sent to registered receivers. 775 */ 776 @SdkConstant(SdkConstant.SdkConstantType.BROADCAST_INTENT_ACTION) 777 public static final String ACTION_POWER_SAVE_MODE_CHANGED 778 = "android.os.action.POWER_SAVE_MODE_CHANGED"; 779 780 /** 781 * Intent that is broadcast when the state of {@link #isPowerSaveMode()} is about to change. 782 * This broadcast is only sent to registered receivers. 783 * 784 * @hide 785 */ 786 @SdkConstant(SdkConstant.SdkConstantType.BROADCAST_INTENT_ACTION) 787 public static final String ACTION_POWER_SAVE_MODE_CHANGING 788 = "android.os.action.POWER_SAVE_MODE_CHANGING"; 789 790 /** @hide */ 791 public static final String EXTRA_POWER_SAVE_MODE = "mode"; 792 793 /** 794 * A wake lock is a mechanism to indicate that your application needs 795 * to have the device stay on. 796 * <p> 797 * Any application using a WakeLock must request the {@code android.permission.WAKE_LOCK} 798 * permission in an {@code <uses-permission>} element of the application's manifest. 799 * Obtain a wake lock by calling {@link PowerManager#newWakeLock(int, String)}. 800 * </p><p> 801 * Call {@link #acquire()} to acquire the wake lock and force the device to stay 802 * on at the level that was requested when the wake lock was created. 803 * </p><p> 804 * Call {@link #release()} when you are done and don't need the lock anymore. 805 * It is very important to do this as soon as possible to avoid running down the 806 * device's battery excessively. 807 * </p> 808 */ 809 public final class WakeLock { 810 private int mFlags; 811 private String mTag; 812 private final String mPackageName; 813 private final IBinder mToken; 814 private int mCount; 815 private boolean mRefCounted = true; 816 private boolean mHeld; 817 private WorkSource mWorkSource; 818 private String mHistoryTag; 819 private final String mTraceName; 820 821 private final Runnable mReleaser = new Runnable() { 822 public void run() { 823 release(); 824 } 825 }; 826 827 WakeLock(int flags, String tag, String packageName) { 828 mFlags = flags; 829 mTag = tag; 830 mPackageName = packageName; 831 mToken = new Binder(); 832 mTraceName = "WakeLock (" + mTag + ")"; 833 } 834 835 @Override 836 protected void finalize() throws Throwable { 837 synchronized (mToken) { 838 if (mHeld) { 839 Log.wtf(TAG, "WakeLock finalized while still held: " + mTag); 840 Trace.asyncTraceEnd(Trace.TRACE_TAG_POWER, mTraceName, 0); 841 try { 842 mService.releaseWakeLock(mToken, 0); 843 } catch (RemoteException e) { 844 } 845 } 846 } 847 } 848 849 /** 850 * Sets whether this WakeLock is reference counted. 851 * <p> 852 * Wake locks are reference counted by default. If a wake lock is 853 * reference counted, then each call to {@link #acquire()} must be 854 * balanced by an equal number of calls to {@link #release()}. If a wake 855 * lock is not reference counted, then one call to {@link #release()} is 856 * sufficient to undo the effect of all previous calls to {@link #acquire()}. 857 * </p> 858 * 859 * @param value True to make the wake lock reference counted, false to 860 * make the wake lock non-reference counted. 861 */ 862 public void setReferenceCounted(boolean value) { 863 synchronized (mToken) { 864 mRefCounted = value; 865 } 866 } 867 868 /** 869 * Acquires the wake lock. 870 * <p> 871 * Ensures that the device is on at the level requested when 872 * the wake lock was created. 873 * </p> 874 */ 875 public void acquire() { 876 synchronized (mToken) { 877 acquireLocked(); 878 } 879 } 880 881 /** 882 * Acquires the wake lock with a timeout. 883 * <p> 884 * Ensures that the device is on at the level requested when 885 * the wake lock was created. The lock will be released after the given timeout 886 * expires. 887 * </p> 888 * 889 * @param timeout The timeout after which to release the wake lock, in milliseconds. 890 */ 891 public void acquire(long timeout) { 892 synchronized (mToken) { 893 acquireLocked(); 894 mHandler.postDelayed(mReleaser, timeout); 895 } 896 } 897 898 private void acquireLocked() { 899 if (!mRefCounted || mCount++ == 0) { 900 // Do this even if the wake lock is already thought to be held (mHeld == true) 901 // because non-reference counted wake locks are not always properly released. 902 // For example, the keyguard's wake lock might be forcibly released by the 903 // power manager without the keyguard knowing. A subsequent call to acquire 904 // should immediately acquire the wake lock once again despite never having 905 // been explicitly released by the keyguard. 906 mHandler.removeCallbacks(mReleaser); 907 Trace.asyncTraceBegin(Trace.TRACE_TAG_POWER, mTraceName, 0); 908 try { 909 mService.acquireWakeLock(mToken, mFlags, mTag, mPackageName, mWorkSource, 910 mHistoryTag); 911 } catch (RemoteException e) { 912 } 913 mHeld = true; 914 } 915 } 916 917 /** 918 * Releases the wake lock. 919 * <p> 920 * This method releases your claim to the CPU or screen being on. 921 * The screen may turn off shortly after you release the wake lock, or it may 922 * not if there are other wake locks still held. 923 * </p> 924 */ 925 public void release() { 926 release(0); 927 } 928 929 /** 930 * Releases the wake lock with flags to modify the release behavior. 931 * <p> 932 * This method releases your claim to the CPU or screen being on. 933 * The screen may turn off shortly after you release the wake lock, or it may 934 * not if there are other wake locks still held. 935 * </p> 936 * 937 * @param flags Combination of flag values to modify the release behavior. 938 * Currently only {@link #WAIT_FOR_PROXIMITY_NEGATIVE} is supported. 939 */ 940 public void release(int flags) { 941 synchronized (mToken) { 942 if (!mRefCounted || --mCount == 0) { 943 mHandler.removeCallbacks(mReleaser); 944 if (mHeld) { 945 Trace.asyncTraceEnd(Trace.TRACE_TAG_POWER, mTraceName, 0); 946 try { 947 mService.releaseWakeLock(mToken, flags); 948 } catch (RemoteException e) { 949 } 950 mHeld = false; 951 } 952 } 953 if (mCount < 0) { 954 throw new RuntimeException("WakeLock under-locked " + mTag); 955 } 956 } 957 } 958 959 /** 960 * Returns true if the wake lock has been acquired but not yet released. 961 * 962 * @return True if the wake lock is held. 963 */ 964 public boolean isHeld() { 965 synchronized (mToken) { 966 return mHeld; 967 } 968 } 969 970 /** 971 * Sets the work source associated with the wake lock. 972 * <p> 973 * The work source is used to determine on behalf of which application 974 * the wake lock is being held. This is useful in the case where a 975 * service is performing work on behalf of an application so that the 976 * cost of that work can be accounted to the application. 977 * </p> 978 * 979 * @param ws The work source, or null if none. 980 */ 981 public void setWorkSource(WorkSource ws) { 982 synchronized (mToken) { 983 if (ws != null && ws.size() == 0) { 984 ws = null; 985 } 986 987 final boolean changed; 988 if (ws == null) { 989 changed = mWorkSource != null; 990 mWorkSource = null; 991 } else if (mWorkSource == null) { 992 changed = true; 993 mWorkSource = new WorkSource(ws); 994 } else { 995 changed = mWorkSource.diff(ws); 996 if (changed) { 997 mWorkSource.set(ws); 998 } 999 } 1000 1001 if (changed && mHeld) { 1002 try { 1003 mService.updateWakeLockWorkSource(mToken, mWorkSource, mHistoryTag); 1004 } catch (RemoteException e) { 1005 } 1006 } 1007 } 1008 } 1009 1010 /** @hide */ 1011 public void setTag(String tag) { 1012 mTag = tag; 1013 } 1014 1015 /** @hide */ 1016 public void setHistoryTag(String tag) { 1017 mHistoryTag = tag; 1018 } 1019 1020 /** @hide */ 1021 public void setUnimportantForLogging(boolean state) { 1022 if (state) mFlags |= UNIMPORTANT_FOR_LOGGING; 1023 else mFlags &= ~UNIMPORTANT_FOR_LOGGING; 1024 } 1025 1026 @Override 1027 public String toString() { 1028 synchronized (mToken) { 1029 return "WakeLock{" 1030 + Integer.toHexString(System.identityHashCode(this)) 1031 + " held=" + mHeld + ", refCount=" + mCount + "}"; 1032 } 1033 } 1034 } 1035} 1036