PowerManager.java revision 6d8fd27e51d799cf7418b14092b5e806d9792812
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.content.Context; 20import android.util.Log; 21 22/** 23 * This class gives you control of the power state of the device. 24 * 25 * <p> 26 * <b>Device battery life will be significantly affected by the use of this API.</b> 27 * Do not acquire {@link WakeLock}s unless you really need them, use the minimum levels 28 * possible, and be sure to release them as soon as possible. 29 * </p><p> 30 * You can obtain an instance of this class by calling 31 * {@link android.content.Context#getSystemService(java.lang.String) Context.getSystemService()}. 32 * </p><p> 33 * The primary API you'll use is {@link #newWakeLock(int, String) newWakeLock()}. 34 * This will create a {@link PowerManager.WakeLock} object. You can then use methods 35 * on the wake lock object to control the power state of the device. 36 * </p><p> 37 * In practice it's quite simple: 38 * {@samplecode 39 * PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE); 40 * PowerManager.WakeLock wl = pm.newWakeLock(PowerManager.SCREEN_DIM_WAKE_LOCK, "My Tag"); 41 * wl.acquire(); 42 * ..screen will stay on during this section.. 43 * wl.release(); 44 * } 45 * </p><p> 46 * The following wake lock levels are defined, with varying effects on system power. 47 * <i>These levels are mutually exclusive - you may only specify one of them.</i> 48 * 49 * <table> 50 * <tr><th>Flag Value</th> 51 * <th>CPU</th> <th>Screen</th> <th>Keyboard</th></tr> 52 * 53 * <tr><td>{@link #PARTIAL_WAKE_LOCK}</td> 54 * <td>On*</td> <td>Off</td> <td>Off</td> 55 * </tr> 56 * 57 * <tr><td>{@link #SCREEN_DIM_WAKE_LOCK}</td> 58 * <td>On</td> <td>Dim</td> <td>Off</td> 59 * </tr> 60 * 61 * <tr><td>{@link #SCREEN_BRIGHT_WAKE_LOCK}</td> 62 * <td>On</td> <td>Bright</td> <td>Off</td> 63 * </tr> 64 * 65 * <tr><td>{@link #FULL_WAKE_LOCK}</td> 66 * <td>On</td> <td>Bright</td> <td>Bright</td> 67 * </tr> 68 * </table> 69 * </p><p> 70 * *<i>If you hold a partial wake lock, the CPU will continue to run, regardless of any 71 * display timeouts or the state of the screen and even after the user presses the power button. 72 * In all other wake locks, the CPU will run, but the user can still put the device to sleep 73 * using the power button.</i> 74 * </p><p> 75 * In addition, you can add two more flags, which affect behavior of the screen only. 76 * <i>These flags have no effect when combined with a {@link #PARTIAL_WAKE_LOCK}.</i></p> 77 * 78 * <table> 79 * <tr><th>Flag Value</th> <th>Description</th></tr> 80 * 81 * <tr><td>{@link #ACQUIRE_CAUSES_WAKEUP}</td> 82 * <td>Normal wake locks don't actually turn on the illumination. Instead, they cause 83 * the illumination to remain on once it turns on (e.g. from user activity). This flag 84 * will force the screen and/or keyboard to turn on immediately, when the WakeLock is 85 * acquired. A typical use would be for notifications which are important for the user to 86 * see immediately.</td> 87 * </tr> 88 * 89 * <tr><td>{@link #ON_AFTER_RELEASE}</td> 90 * <td>If this flag is set, the user activity timer will be reset when the WakeLock is 91 * released, causing the illumination to remain on a bit longer. This can be used to 92 * reduce flicker if you are cycling between wake lock conditions.</td> 93 * </tr> 94 * </table> 95 * <p> 96 * Any application using a WakeLock must request the {@code android.permission.WAKE_LOCK} 97 * permission in an {@code <uses-permission>} element of the application's manifest. 98 * </p> 99 */ 100public final class PowerManager { 101 private static final String TAG = "PowerManager"; 102 103 /* NOTE: Wake lock levels were previously defined as a bit field, except that only a few 104 * combinations were actually supported so the bit field was removed. This explains 105 * why the numbering scheme is so odd. If adding a new wake lock level, any unused 106 * value can be used. 107 */ 108 109 /** 110 * Wake lock level: Ensures that the CPU is running; the screen and keyboard 111 * backlight will be allowed to go off. 112 * <p> 113 * If the user presses the power button, then the screen will be turned off 114 * but the CPU will be kept on until all partial wake locks have been released. 115 * </p> 116 */ 117 public static final int PARTIAL_WAKE_LOCK = 0x00000001; 118 119 /** 120 * Wake lock level: Ensures that the screen is on (but may be dimmed); 121 * the keyboard backlight will be allowed to go off. 122 * <p> 123 * If the user presses the power button, then the {@link #SCREEN_DIM_WAKE_LOCK} will be 124 * implicitly released by the system, causing both the screen and the CPU to be turned off. 125 * Contrast with {@link #PARTIAL_WAKE_LOCK}. 126 * </p> 127 * 128 * @deprecated Most applications should use 129 * {@link android.view.WindowManager.LayoutParams#FLAG_KEEP_SCREEN_ON} instead 130 * of this type of wake lock, as it will be correctly managed by the platform 131 * as the user moves between applications and doesn't require a special permission. 132 */ 133 @Deprecated 134 public static final int SCREEN_DIM_WAKE_LOCK = 0x00000006; 135 136 /** 137 * Wake lock level: Ensures that the screen is on at full brightness; 138 * the keyboard backlight will be allowed to go off. 139 * <p> 140 * If the user presses the power button, then the {@link #SCREEN_BRIGHT_WAKE_LOCK} will be 141 * implicitly released by the system, causing both the screen and the CPU to be turned off. 142 * Contrast with {@link #PARTIAL_WAKE_LOCK}. 143 * </p> 144 * 145 * @deprecated Most applications should use 146 * {@link android.view.WindowManager.LayoutParams#FLAG_KEEP_SCREEN_ON} instead 147 * of this type of wake lock, as it will be correctly managed by the platform 148 * as the user moves between applications and doesn't require a special permission. 149 */ 150 @Deprecated 151 public static final int SCREEN_BRIGHT_WAKE_LOCK = 0x0000000a; 152 153 /** 154 * Wake lock level: Ensures that the screen and keyboard backlight are on at 155 * full brightness. 156 * <p> 157 * If the user presses the power button, then the {@link #FULL_WAKE_LOCK} will be 158 * implicitly released by the system, causing both the screen and the CPU to be turned off. 159 * Contrast with {@link #PARTIAL_WAKE_LOCK}. 160 * </p> 161 * 162 * @deprecated Most applications should use 163 * {@link android.view.WindowManager.LayoutParams#FLAG_KEEP_SCREEN_ON} instead 164 * of this type of wake lock, as it will be correctly managed by the platform 165 * as the user moves between applications and doesn't require a special permission. 166 */ 167 @Deprecated 168 public static final int FULL_WAKE_LOCK = 0x0000001a; 169 170 /** 171 * Wake lock level: Turns the screen off when the proximity sensor activates. 172 * <p> 173 * If the proximity sensor detects that an object is nearby, the screen turns off 174 * immediately. Shortly after the object moves away, the screen turns on again. 175 * </p><p> 176 * A proximity wake lock does not prevent the device from falling asleep 177 * unlike {@link #FULL_WAKE_LOCK}, {@link #SCREEN_BRIGHT_WAKE_LOCK} and 178 * {@link #SCREEN_DIM_WAKE_LOCK}. If there is no user activity and no other 179 * wake locks are held, then the device will fall asleep (and lock) as usual. 180 * However, the device will not fall asleep while the screen has been turned off 181 * by the proximity sensor because it effectively counts as ongoing user activity. 182 * </p><p> 183 * Since not all devices have proximity sensors, use {@link #isWakeLockLevelSupported} 184 * to determine whether this wake lock level is supported. 185 * </p><p> 186 * Cannot be used with {@link #ACQUIRE_CAUSES_WAKEUP}. 187 * </p> 188 * 189 * {@hide} 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> 200 * 201 * {@hide} 202 */ 203 public static final int DOZE_WAKE_LOCK = 0x00000040; 204 205 /** 206 * Mask for the wake lock level component of a combined wake lock level and flags integer. 207 * 208 * @hide 209 */ 210 public static final int WAKE_LOCK_LEVEL_MASK = 0x0000ffff; 211 212 /** 213 * Wake lock flag: Turn the screen on when the wake lock is acquired. 214 * <p> 215 * Normally wake locks don't actually wake the device, they just cause 216 * the screen to remain on once it's already on. Think of the video player 217 * application as the normal behavior. Notifications that pop up and want 218 * the device to be on are the exception; use this flag to be like them. 219 * </p><p> 220 * Cannot be used with {@link #PARTIAL_WAKE_LOCK}. 221 * </p> 222 */ 223 public static final int ACQUIRE_CAUSES_WAKEUP = 0x10000000; 224 225 /** 226 * Wake lock flag: When this wake lock is released, poke the user activity timer 227 * so the screen stays on for a little longer. 228 * <p> 229 * Will not turn the screen on if it is not already on. 230 * See {@link #ACQUIRE_CAUSES_WAKEUP} if you want that. 231 * </p><p> 232 * Cannot be used with {@link #PARTIAL_WAKE_LOCK}. 233 * </p> 234 */ 235 public static final int ON_AFTER_RELEASE = 0x20000000; 236 237 /** 238 * Flag for {@link WakeLock#release release(int)} to defer releasing a 239 * {@link #PROXIMITY_SCREEN_OFF_WAKE_LOCK} wake lock until the proximity sensor returns 240 * a negative value. 241 * 242 * {@hide} 243 */ 244 public static final int WAIT_FOR_PROXIMITY_NEGATIVE = 1; 245 246 /** 247 * Brightness value for fully on. 248 * @hide 249 */ 250 public static final int BRIGHTNESS_ON = 255; 251 252 /** 253 * Brightness value for fully off. 254 * @hide 255 */ 256 public static final int BRIGHTNESS_OFF = 0; 257 258 // Note: Be sure to update android.os.BatteryStats and PowerManager.h 259 // if adding or modifying user activity event constants. 260 261 /** 262 * User activity event type: Unspecified event type. 263 * @hide 264 */ 265 public static final int USER_ACTIVITY_EVENT_OTHER = 0; 266 267 /** 268 * User activity event type: Button or key pressed or released. 269 * @hide 270 */ 271 public static final int USER_ACTIVITY_EVENT_BUTTON = 1; 272 273 /** 274 * User activity event type: Touch down, move or up. 275 * @hide 276 */ 277 public static final int USER_ACTIVITY_EVENT_TOUCH = 2; 278 279 /** 280 * User activity flag: Do not restart the user activity timeout or brighten 281 * the display in response to user activity if it is already dimmed. 282 * @hide 283 */ 284 public static final int USER_ACTIVITY_FLAG_NO_CHANGE_LIGHTS = 1 << 0; 285 286 /** 287 * Go to sleep reason code: Going to sleep due by user request. 288 * @hide 289 */ 290 public static final int GO_TO_SLEEP_REASON_USER = 0; 291 292 /** 293 * Go to sleep reason code: Going to sleep due by request of the 294 * device administration policy. 295 * @hide 296 */ 297 public static final int GO_TO_SLEEP_REASON_DEVICE_ADMIN = 1; 298 299 /** 300 * Go to sleep reason code: Going to sleep due to a screen timeout. 301 * @hide 302 */ 303 public static final int GO_TO_SLEEP_REASON_TIMEOUT = 2; 304 305 /** 306 * Go to sleep flag: Skip dozing state and directly go to full sleep. 307 * @hide 308 */ 309 public static final int GO_TO_SLEEP_FLAG_NO_DOZE = 1 << 0; 310 311 final Context mContext; 312 final IPowerManager mService; 313 final Handler mHandler; 314 315 /** 316 * {@hide} 317 */ 318 public PowerManager(Context context, IPowerManager service, Handler handler) { 319 mContext = context; 320 mService = service; 321 mHandler = handler; 322 } 323 324 /** 325 * Gets the minimum supported screen brightness setting. 326 * The screen may be allowed to become dimmer than this value but 327 * this is the minimum value that can be set by the user. 328 * @hide 329 */ 330 public int getMinimumScreenBrightnessSetting() { 331 return mContext.getResources().getInteger( 332 com.android.internal.R.integer.config_screenBrightnessSettingMinimum); 333 } 334 335 /** 336 * Gets the maximum supported screen brightness setting. 337 * The screen may be allowed to become dimmer than this value but 338 * this is the maximum value that can be set by the user. 339 * @hide 340 */ 341 public int getMaximumScreenBrightnessSetting() { 342 return mContext.getResources().getInteger( 343 com.android.internal.R.integer.config_screenBrightnessSettingMaximum); 344 } 345 346 /** 347 * Gets the default screen brightness setting. 348 * @hide 349 */ 350 public int getDefaultScreenBrightnessSetting() { 351 return mContext.getResources().getInteger( 352 com.android.internal.R.integer.config_screenBrightnessSettingDefault); 353 } 354 355 /** 356 * Returns true if the screen auto-brightness adjustment setting should 357 * be available in the UI. This setting is experimental and disabled by default. 358 * @hide 359 */ 360 public static boolean useScreenAutoBrightnessAdjustmentFeature() { 361 return SystemProperties.getBoolean("persist.power.useautobrightadj", false); 362 } 363 364 /** 365 * Returns true if the twilight service should be used to adjust screen brightness 366 * policy. This setting is experimental and disabled by default. 367 * @hide 368 */ 369 public static boolean useTwilightAdjustmentFeature() { 370 return SystemProperties.getBoolean("persist.power.usetwilightadj", false); 371 } 372 373 /** 374 * Creates a new wake lock with the specified level and flags. 375 * <p> 376 * The {@code levelAndFlags} parameter specifies a wake lock level and optional flags 377 * combined using the logical OR operator. 378 * </p><p> 379 * The wake lock levels are: {@link #PARTIAL_WAKE_LOCK}, 380 * {@link #FULL_WAKE_LOCK}, {@link #SCREEN_DIM_WAKE_LOCK} 381 * and {@link #SCREEN_BRIGHT_WAKE_LOCK}. Exactly one wake lock level must be 382 * specified as part of the {@code levelAndFlags} parameter. 383 * </p><p> 384 * The wake lock flags are: {@link #ACQUIRE_CAUSES_WAKEUP} 385 * and {@link #ON_AFTER_RELEASE}. Multiple flags can be combined as part of the 386 * {@code levelAndFlags} parameters. 387 * </p><p> 388 * Call {@link WakeLock#acquire() acquire()} on the object to acquire the 389 * wake lock, and {@link WakeLock#release release()} when you are done. 390 * </p><p> 391 * {@samplecode 392 * PowerManager pm = (PowerManager)mContext.getSystemService( 393 * Context.POWER_SERVICE); 394 * PowerManager.WakeLock wl = pm.newWakeLock( 395 * PowerManager.SCREEN_DIM_WAKE_LOCK 396 * | PowerManager.ON_AFTER_RELEASE, 397 * TAG); 398 * wl.acquire(); 399 * // ... do work... 400 * wl.release(); 401 * } 402 * </p><p> 403 * Although a wake lock can be created without special permissions, 404 * the {@link android.Manifest.permission#WAKE_LOCK} permission is 405 * required to actually acquire or release the wake lock that is returned. 406 * </p><p class="note"> 407 * If using this to keep the screen on, you should strongly consider using 408 * {@link android.view.WindowManager.LayoutParams#FLAG_KEEP_SCREEN_ON} instead. 409 * This window flag will be correctly managed by the platform 410 * as the user moves between applications and doesn't require a special permission. 411 * </p> 412 * 413 * @param levelAndFlags Combination of wake lock level and flag values defining 414 * the requested behavior of the WakeLock. 415 * @param tag Your class name (or other tag) for debugging purposes. 416 * 417 * @see WakeLock#acquire() 418 * @see WakeLock#release() 419 * @see #PARTIAL_WAKE_LOCK 420 * @see #FULL_WAKE_LOCK 421 * @see #SCREEN_DIM_WAKE_LOCK 422 * @see #SCREEN_BRIGHT_WAKE_LOCK 423 * @see #ACQUIRE_CAUSES_WAKEUP 424 * @see #ON_AFTER_RELEASE 425 */ 426 public WakeLock newWakeLock(int levelAndFlags, String tag) { 427 validateWakeLockParameters(levelAndFlags, tag); 428 return new WakeLock(levelAndFlags, tag, mContext.getOpPackageName()); 429 } 430 431 /** @hide */ 432 public static void validateWakeLockParameters(int levelAndFlags, String tag) { 433 switch (levelAndFlags & WAKE_LOCK_LEVEL_MASK) { 434 case PARTIAL_WAKE_LOCK: 435 case SCREEN_DIM_WAKE_LOCK: 436 case SCREEN_BRIGHT_WAKE_LOCK: 437 case FULL_WAKE_LOCK: 438 case PROXIMITY_SCREEN_OFF_WAKE_LOCK: 439 case DOZE_WAKE_LOCK: 440 break; 441 default: 442 throw new IllegalArgumentException("Must specify a valid wake lock level."); 443 } 444 if (tag == null) { 445 throw new IllegalArgumentException("The tag must not be null."); 446 } 447 } 448 449 /** 450 * Notifies the power manager that user activity happened. 451 * <p> 452 * Resets the auto-off timer and brightens the screen if the device 453 * is not asleep. This is what happens normally when a key or the touch 454 * screen is pressed or when some other user activity occurs. 455 * This method does not wake up the device if it has been put to sleep. 456 * </p><p> 457 * Requires the {@link android.Manifest.permission#DEVICE_POWER} permission. 458 * </p> 459 * 460 * @param when The time of the user activity, in the {@link SystemClock#uptimeMillis()} 461 * time base. This timestamp is used to correctly order the user activity request with 462 * other power management functions. It should be set 463 * to the timestamp of the input event that caused the user activity. 464 * @param noChangeLights If true, does not cause the keyboard backlight to turn on 465 * because of this event. This is set when the power key is pressed. 466 * We want the device to stay on while the button is down, but we're about 467 * to turn off the screen so we don't want the keyboard backlight to turn on again. 468 * Otherwise the lights flash on and then off and it looks weird. 469 * 470 * @see #wakeUp 471 * @see #goToSleep 472 */ 473 public void userActivity(long when, boolean noChangeLights) { 474 try { 475 mService.userActivity(when, USER_ACTIVITY_EVENT_OTHER, 476 noChangeLights ? USER_ACTIVITY_FLAG_NO_CHANGE_LIGHTS : 0); 477 } catch (RemoteException e) { 478 } 479 } 480 481 /** 482 * Forces the device to go to sleep. 483 * <p> 484 * Overrides all the wake locks that are held. 485 * This is what happens when the power key is pressed to turn off the screen. 486 * </p><p> 487 * Requires the {@link android.Manifest.permission#DEVICE_POWER} permission. 488 * </p> 489 * 490 * @param time The time when the request to go to sleep was issued, in the 491 * {@link SystemClock#uptimeMillis()} time base. This timestamp is used to correctly 492 * order the go to sleep request with other power management functions. It should be set 493 * to the timestamp of the input event that caused the request to go to sleep. 494 * 495 * @see #userActivity 496 * @see #wakeUp 497 */ 498 public void goToSleep(long time) { 499 goToSleep(time, GO_TO_SLEEP_REASON_USER, 0); 500 } 501 502 /** 503 * @hide 504 */ 505 public void goToSleep(long time, int reason, int flags) { 506 try { 507 mService.goToSleep(time, reason, flags); 508 } catch (RemoteException e) { 509 } 510 } 511 512 /** 513 * Forces the device to wake up from sleep. 514 * <p> 515 * If the device is currently asleep, wakes it up, otherwise does nothing. 516 * This is what happens when the power key is pressed to turn on the screen. 517 * </p><p> 518 * Requires the {@link android.Manifest.permission#DEVICE_POWER} permission. 519 * </p> 520 * 521 * @param time The time when the request to wake up was issued, in the 522 * {@link SystemClock#uptimeMillis()} time base. This timestamp is used to correctly 523 * order the wake up request with other power management functions. It should be set 524 * to the timestamp of the input event that caused the request to wake up. 525 * 526 * @see #userActivity 527 * @see #goToSleep 528 */ 529 public void wakeUp(long time) { 530 try { 531 mService.wakeUp(time); 532 } catch (RemoteException e) { 533 } 534 } 535 536 /** 537 * Forces the device to start napping. 538 * <p> 539 * If the device is currently awake, starts dreaming, otherwise does nothing. 540 * When the dream ends or if the dream cannot be started, the device will 541 * either wake up or go to sleep depending on whether there has been recent 542 * user activity. 543 * </p><p> 544 * Requires the {@link android.Manifest.permission#DEVICE_POWER} permission. 545 * </p> 546 * 547 * @param time The time when the request to nap was issued, in the 548 * {@link SystemClock#uptimeMillis()} time base. This timestamp is used to correctly 549 * order the nap request with other power management functions. It should be set 550 * to the timestamp of the input event that caused the request to nap. 551 * 552 * @see #wakeUp 553 * @see #goToSleep 554 * 555 * @hide 556 */ 557 public void nap(long time) { 558 try { 559 mService.nap(time); 560 } catch (RemoteException e) { 561 } 562 } 563 564 /** 565 * Sets the brightness of the backlights (screen, keyboard, button). 566 * <p> 567 * Requires the {@link android.Manifest.permission#DEVICE_POWER} permission. 568 * </p> 569 * 570 * @param brightness The brightness value from 0 to 255. 571 * 572 * {@hide} 573 */ 574 public void setBacklightBrightness(int brightness) { 575 try { 576 mService.setTemporaryScreenBrightnessSettingOverride(brightness); 577 } catch (RemoteException e) { 578 } 579 } 580 581 /** 582 * Returns true if the specified wake lock level is supported. 583 * 584 * @param level The wake lock level to check. 585 * @return True if the specified wake lock level is supported. 586 * 587 * {@hide} 588 */ 589 public boolean isWakeLockLevelSupported(int level) { 590 try { 591 return mService.isWakeLockLevelSupported(level); 592 } catch (RemoteException e) { 593 return false; 594 } 595 } 596 597 /** 598 * Returns true if the device is in an interactive state. 599 * <p> 600 * For historical reasons, the name of this method refers to the power state of 601 * the screen but it actually describes the overall interactive state of 602 * the device. This method has been replaced by {@link #isInteractive}. 603 * </p><p> 604 * The value returned by this method only indicates whether the device is 605 * in an interactive state which may have nothing to do with the screen being 606 * on or off. To determine the actual state of the screen, 607 * use {@link android.view.Display#getState}. 608 * </p> 609 * 610 * @return True if the device is in an interactive state. 611 * 612 * @deprecated Use {@link #isInteractive} instead. 613 */ 614 @Deprecated 615 public boolean isScreenOn() { 616 return isInteractive(); 617 } 618 619 /** 620 * Returns true if the device is in an interactive state. 621 * <p> 622 * When this method returns true, the device is awake and ready to interact 623 * with the user (although this is not a guarantee that the user is actively 624 * interacting with the device just this moment). The main screen is usually 625 * turned on while in this state. Certain features, such as the proximity 626 * sensor, may temporarily turn off the screen while still leaving the device in an 627 * interactive state. Note in particular that the device is still considered 628 * to be interactive while dreaming (since dreams can be interactive) but not 629 * when it is dozing or asleep. 630 * </p><p> 631 * When this method returns false, the device is dozing or asleep and must 632 * be awoken before it will become ready to interact with the user again. The 633 * main screen is usually turned off while in this state. Certain features, 634 * such as "ambient mode" may cause the main screen to remain on (albeit in a 635 * low power state) to display system-provided content while the device dozes. 636 * </p><p> 637 * The system will send a {@link android.content.Intent#ACTION_SCREEN_ON screen on} 638 * or {@link android.content.Intent#ACTION_SCREEN_OFF screen off} broadcast 639 * whenever the interactive state of the device changes. For historical reasons, 640 * the names of these broadcasts refer to the power state of the screen 641 * but they are actually sent in response to changes in the overall interactive 642 * state of the device, as described by this method. 643 * </p><p> 644 * Services may use the non-interactive state as a hint to conserve power 645 * since the user is not present. 646 * </p> 647 * 648 * @return True if the device is in an interactive state. 649 * 650 * @see android.content.Intent#ACTION_SCREEN_ON 651 * @see android.content.Intent#ACTION_SCREEN_OFF 652 */ 653 public boolean isInteractive() { 654 try { 655 return mService.isInteractive(); 656 } catch (RemoteException e) { 657 return false; 658 } 659 } 660 661 /** 662 * Reboot the device. Will not return if the reboot is successful. 663 * <p> 664 * Requires the {@link android.Manifest.permission#REBOOT} permission. 665 * </p> 666 * 667 * @param reason code to pass to the kernel (e.g., "recovery") to 668 * request special boot modes, or null. 669 */ 670 public void reboot(String reason) { 671 try { 672 mService.reboot(false, reason, true); 673 } catch (RemoteException e) { 674 } 675 } 676 677 /** 678 * A wake lock is a mechanism to indicate that your application needs 679 * to have the device stay on. 680 * <p> 681 * Any application using a WakeLock must request the {@code android.permission.WAKE_LOCK} 682 * permission in an {@code <uses-permission>} element of the application's manifest. 683 * Obtain a wake lock by calling {@link PowerManager#newWakeLock(int, String)}. 684 * </p><p> 685 * Call {@link #acquire()} to acquire the wake lock and force the device to stay 686 * on at the level that was requested when the wake lock was created. 687 * </p><p> 688 * Call {@link #release()} when you are done and don't need the lock anymore. 689 * It is very important to do this as soon as possible to avoid running down the 690 * device's battery excessively. 691 * </p> 692 */ 693 public final class WakeLock { 694 private final int mFlags; 695 private final String mTag; 696 private final String mPackageName; 697 private final IBinder mToken; 698 private int mCount; 699 private boolean mRefCounted = true; 700 private boolean mHeld; 701 private WorkSource mWorkSource; 702 703 private final Runnable mReleaser = new Runnable() { 704 public void run() { 705 release(); 706 } 707 }; 708 709 WakeLock(int flags, String tag, String packageName) { 710 mFlags = flags; 711 mTag = tag; 712 mPackageName = packageName; 713 mToken = new Binder(); 714 } 715 716 @Override 717 protected void finalize() throws Throwable { 718 synchronized (mToken) { 719 if (mHeld) { 720 Log.wtf(TAG, "WakeLock finalized while still held: " + mTag); 721 try { 722 mService.releaseWakeLock(mToken, 0); 723 } catch (RemoteException e) { 724 } 725 } 726 } 727 } 728 729 /** 730 * Sets whether this WakeLock is reference counted. 731 * <p> 732 * Wake locks are reference counted by default. If a wake lock is 733 * reference counted, then each call to {@link #acquire()} must be 734 * balanced by an equal number of calls to {@link #release()}. If a wake 735 * lock is not reference counted, then one call to {@link #release()} is 736 * sufficient to undo the effect of all previous calls to {@link #acquire()}. 737 * </p> 738 * 739 * @param value True to make the wake lock reference counted, false to 740 * make the wake lock non-reference counted. 741 */ 742 public void setReferenceCounted(boolean value) { 743 synchronized (mToken) { 744 mRefCounted = value; 745 } 746 } 747 748 /** 749 * Acquires the wake lock. 750 * <p> 751 * Ensures that the device is on at the level requested when 752 * the wake lock was created. 753 * </p> 754 */ 755 public void acquire() { 756 synchronized (mToken) { 757 acquireLocked(); 758 } 759 } 760 761 /** 762 * Acquires the wake lock with a timeout. 763 * <p> 764 * Ensures that the device is on at the level requested when 765 * the wake lock was created. The lock will be released after the given timeout 766 * expires. 767 * </p> 768 * 769 * @param timeout The timeout after which to release the wake lock, in milliseconds. 770 */ 771 public void acquire(long timeout) { 772 synchronized (mToken) { 773 acquireLocked(); 774 mHandler.postDelayed(mReleaser, timeout); 775 } 776 } 777 778 private void acquireLocked() { 779 if (!mRefCounted || mCount++ == 0) { 780 // Do this even if the wake lock is already thought to be held (mHeld == true) 781 // because non-reference counted wake locks are not always properly released. 782 // For example, the keyguard's wake lock might be forcibly released by the 783 // power manager without the keyguard knowing. A subsequent call to acquire 784 // should immediately acquire the wake lock once again despite never having 785 // been explicitly released by the keyguard. 786 mHandler.removeCallbacks(mReleaser); 787 try { 788 mService.acquireWakeLock(mToken, mFlags, mTag, mPackageName, mWorkSource); 789 } catch (RemoteException e) { 790 } 791 mHeld = true; 792 } 793 } 794 795 /** 796 * Releases the wake lock. 797 * <p> 798 * This method releases your claim to the CPU or screen being on. 799 * The screen may turn off shortly after you release the wake lock, or it may 800 * not if there are other wake locks still held. 801 * </p> 802 */ 803 public void release() { 804 release(0); 805 } 806 807 /** 808 * Releases the wake lock with flags to modify the release behavior. 809 * <p> 810 * This method releases your claim to the CPU or screen being on. 811 * The screen may turn off shortly after you release the wake lock, or it may 812 * not if there are other wake locks still held. 813 * </p> 814 * 815 * @param flags Combination of flag values to modify the release behavior. 816 * Currently only {@link #WAIT_FOR_PROXIMITY_NEGATIVE} is supported. 817 * 818 * {@hide} 819 */ 820 public void release(int flags) { 821 synchronized (mToken) { 822 if (!mRefCounted || --mCount == 0) { 823 mHandler.removeCallbacks(mReleaser); 824 if (mHeld) { 825 try { 826 mService.releaseWakeLock(mToken, flags); 827 } catch (RemoteException e) { 828 } 829 mHeld = false; 830 } 831 } 832 if (mCount < 0) { 833 throw new RuntimeException("WakeLock under-locked " + mTag); 834 } 835 } 836 } 837 838 /** 839 * Returns true if the wake lock has been acquired but not yet released. 840 * 841 * @return True if the wake lock is held. 842 */ 843 public boolean isHeld() { 844 synchronized (mToken) { 845 return mHeld; 846 } 847 } 848 849 /** 850 * Sets the work source associated with the wake lock. 851 * <p> 852 * The work source is used to determine on behalf of which application 853 * the wake lock is being held. This is useful in the case where a 854 * service is performing work on behalf of an application so that the 855 * cost of that work can be accounted to the application. 856 * </p> 857 * 858 * @param ws The work source, or null if none. 859 */ 860 public void setWorkSource(WorkSource ws) { 861 synchronized (mToken) { 862 if (ws != null && ws.size() == 0) { 863 ws = null; 864 } 865 866 final boolean changed; 867 if (ws == null) { 868 changed = mWorkSource != null; 869 mWorkSource = null; 870 } else if (mWorkSource == null) { 871 changed = true; 872 mWorkSource = new WorkSource(ws); 873 } else { 874 changed = mWorkSource.diff(ws); 875 if (changed) { 876 mWorkSource.set(ws); 877 } 878 } 879 880 if (changed && mHeld) { 881 try { 882 mService.updateWakeLockWorkSource(mToken, mWorkSource); 883 } catch (RemoteException e) { 884 } 885 } 886 } 887 } 888 889 @Override 890 public String toString() { 891 synchronized (mToken) { 892 return "WakeLock{" 893 + Integer.toHexString(System.identityHashCode(this)) 894 + " held=" + mHeld + ", refCount=" + mCount + "}"; 895 } 896 } 897 } 898} 899