PowerManager.java revision 037c33eae74bee2774897d969d48947f9abe254f
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 final Context mContext; 306 final IPowerManager mService; 307 final Handler mHandler; 308 309 /** 310 * {@hide} 311 */ 312 public PowerManager(Context context, IPowerManager service, Handler handler) { 313 mContext = context; 314 mService = service; 315 mHandler = handler; 316 } 317 318 /** 319 * Gets the minimum supported screen brightness setting. 320 * The screen may be allowed to become dimmer than this value but 321 * this is the minimum value that can be set by the user. 322 * @hide 323 */ 324 public int getMinimumScreenBrightnessSetting() { 325 return mContext.getResources().getInteger( 326 com.android.internal.R.integer.config_screenBrightnessSettingMinimum); 327 } 328 329 /** 330 * Gets the maximum supported screen brightness setting. 331 * The screen may be allowed to become dimmer than this value but 332 * this is the maximum value that can be set by the user. 333 * @hide 334 */ 335 public int getMaximumScreenBrightnessSetting() { 336 return mContext.getResources().getInteger( 337 com.android.internal.R.integer.config_screenBrightnessSettingMaximum); 338 } 339 340 /** 341 * Gets the default screen brightness setting. 342 * @hide 343 */ 344 public int getDefaultScreenBrightnessSetting() { 345 return mContext.getResources().getInteger( 346 com.android.internal.R.integer.config_screenBrightnessSettingDefault); 347 } 348 349 /** 350 * Returns true if the screen auto-brightness adjustment setting should 351 * be available in the UI. This setting is experimental and disabled by default. 352 * @hide 353 */ 354 public static boolean useScreenAutoBrightnessAdjustmentFeature() { 355 return SystemProperties.getBoolean("persist.power.useautobrightadj", false); 356 } 357 358 /** 359 * Returns true if the twilight service should be used to adjust screen brightness 360 * policy. This setting is experimental and disabled by default. 361 * @hide 362 */ 363 public static boolean useTwilightAdjustmentFeature() { 364 return SystemProperties.getBoolean("persist.power.usetwilightadj", false); 365 } 366 367 /** 368 * Creates a new wake lock with the specified level and flags. 369 * <p> 370 * The {@code levelAndFlags} parameter specifies a wake lock level and optional flags 371 * combined using the logical OR operator. 372 * </p><p> 373 * The wake lock levels are: {@link #PARTIAL_WAKE_LOCK}, 374 * {@link #FULL_WAKE_LOCK}, {@link #SCREEN_DIM_WAKE_LOCK} 375 * and {@link #SCREEN_BRIGHT_WAKE_LOCK}. Exactly one wake lock level must be 376 * specified as part of the {@code levelAndFlags} parameter. 377 * </p><p> 378 * The wake lock flags are: {@link #ACQUIRE_CAUSES_WAKEUP} 379 * and {@link #ON_AFTER_RELEASE}. Multiple flags can be combined as part of the 380 * {@code levelAndFlags} parameters. 381 * </p><p> 382 * Call {@link WakeLock#acquire() acquire()} on the object to acquire the 383 * wake lock, and {@link WakeLock#release release()} when you are done. 384 * </p><p> 385 * {@samplecode 386 * PowerManager pm = (PowerManager)mContext.getSystemService( 387 * Context.POWER_SERVICE); 388 * PowerManager.WakeLock wl = pm.newWakeLock( 389 * PowerManager.SCREEN_DIM_WAKE_LOCK 390 * | PowerManager.ON_AFTER_RELEASE, 391 * TAG); 392 * wl.acquire(); 393 * // ... do work... 394 * wl.release(); 395 * } 396 * </p><p> 397 * Although a wake lock can be created without special permissions, 398 * the {@link android.Manifest.permission#WAKE_LOCK} permission is 399 * required to actually acquire or release the wake lock that is returned. 400 * </p><p class="note"> 401 * If using this to keep the screen on, you should strongly consider using 402 * {@link android.view.WindowManager.LayoutParams#FLAG_KEEP_SCREEN_ON} instead. 403 * This window flag will be correctly managed by the platform 404 * as the user moves between applications and doesn't require a special permission. 405 * </p> 406 * 407 * @param levelAndFlags Combination of wake lock level and flag values defining 408 * the requested behavior of the WakeLock. 409 * @param tag Your class name (or other tag) for debugging purposes. 410 * 411 * @see WakeLock#acquire() 412 * @see WakeLock#release() 413 * @see #PARTIAL_WAKE_LOCK 414 * @see #FULL_WAKE_LOCK 415 * @see #SCREEN_DIM_WAKE_LOCK 416 * @see #SCREEN_BRIGHT_WAKE_LOCK 417 * @see #ACQUIRE_CAUSES_WAKEUP 418 * @see #ON_AFTER_RELEASE 419 */ 420 public WakeLock newWakeLock(int levelAndFlags, String tag) { 421 validateWakeLockParameters(levelAndFlags, tag); 422 return new WakeLock(levelAndFlags, tag, mContext.getOpPackageName()); 423 } 424 425 /** @hide */ 426 public static void validateWakeLockParameters(int levelAndFlags, String tag) { 427 switch (levelAndFlags & WAKE_LOCK_LEVEL_MASK) { 428 case PARTIAL_WAKE_LOCK: 429 case SCREEN_DIM_WAKE_LOCK: 430 case SCREEN_BRIGHT_WAKE_LOCK: 431 case FULL_WAKE_LOCK: 432 case PROXIMITY_SCREEN_OFF_WAKE_LOCK: 433 case DOZE_WAKE_LOCK: 434 break; 435 default: 436 throw new IllegalArgumentException("Must specify a valid wake lock level."); 437 } 438 if (tag == null) { 439 throw new IllegalArgumentException("The tag must not be null."); 440 } 441 } 442 443 /** 444 * Notifies the power manager that user activity happened. 445 * <p> 446 * Resets the auto-off timer and brightens the screen if the device 447 * is not asleep. This is what happens normally when a key or the touch 448 * screen is pressed or when some other user activity occurs. 449 * This method does not wake up the device if it has been put to sleep. 450 * </p><p> 451 * Requires the {@link android.Manifest.permission#DEVICE_POWER} permission. 452 * </p> 453 * 454 * @param when The time of the user activity, in the {@link SystemClock#uptimeMillis()} 455 * time base. This timestamp is used to correctly order the user activity request with 456 * other power management functions. It should be set 457 * to the timestamp of the input event that caused the user activity. 458 * @param noChangeLights If true, does not cause the keyboard backlight to turn on 459 * because of this event. This is set when the power key is pressed. 460 * We want the device to stay on while the button is down, but we're about 461 * to turn off the screen so we don't want the keyboard backlight to turn on again. 462 * Otherwise the lights flash on and then off and it looks weird. 463 * 464 * @see #wakeUp 465 * @see #goToSleep 466 */ 467 public void userActivity(long when, boolean noChangeLights) { 468 try { 469 mService.userActivity(when, USER_ACTIVITY_EVENT_OTHER, 470 noChangeLights ? USER_ACTIVITY_FLAG_NO_CHANGE_LIGHTS : 0); 471 } catch (RemoteException e) { 472 } 473 } 474 475 /** 476 * Forces the device to go to sleep. 477 * <p> 478 * Overrides all the wake locks that are held. 479 * This is what happens when the power key is pressed to turn off the screen. 480 * </p><p> 481 * Requires the {@link android.Manifest.permission#DEVICE_POWER} permission. 482 * </p> 483 * 484 * @param time The time when the request to go to sleep was issued, in the 485 * {@link SystemClock#uptimeMillis()} time base. This timestamp is used to correctly 486 * order the go to sleep request with other power management functions. It should be set 487 * to the timestamp of the input event that caused the request to go to sleep. 488 * 489 * @see #userActivity 490 * @see #wakeUp 491 */ 492 public void goToSleep(long time) { 493 try { 494 mService.goToSleep(time, GO_TO_SLEEP_REASON_USER); 495 } catch (RemoteException e) { 496 } 497 } 498 499 /** 500 * Forces the device to wake up from sleep. 501 * <p> 502 * If the device is currently asleep, wakes it up, otherwise does nothing. 503 * This is what happens when the power key is pressed to turn on the screen. 504 * </p><p> 505 * Requires the {@link android.Manifest.permission#DEVICE_POWER} permission. 506 * </p> 507 * 508 * @param time The time when the request to wake up was issued, in the 509 * {@link SystemClock#uptimeMillis()} time base. This timestamp is used to correctly 510 * order the wake up request with other power management functions. It should be set 511 * to the timestamp of the input event that caused the request to wake up. 512 * 513 * @see #userActivity 514 * @see #goToSleep 515 */ 516 public void wakeUp(long time) { 517 try { 518 mService.wakeUp(time); 519 } catch (RemoteException e) { 520 } 521 } 522 523 /** 524 * Forces the device to start napping. 525 * <p> 526 * If the device is currently awake, starts dreaming, otherwise does nothing. 527 * When the dream ends or if the dream cannot be started, the device will 528 * either wake up or go to sleep depending on whether there has been recent 529 * user activity. 530 * </p><p> 531 * Requires the {@link android.Manifest.permission#DEVICE_POWER} permission. 532 * </p> 533 * 534 * @param time The time when the request to nap was issued, in the 535 * {@link SystemClock#uptimeMillis()} time base. This timestamp is used to correctly 536 * order the nap request with other power management functions. It should be set 537 * to the timestamp of the input event that caused the request to nap. 538 * 539 * @see #wakeUp 540 * @see #goToSleep 541 * 542 * @hide 543 */ 544 public void nap(long time) { 545 try { 546 mService.nap(time); 547 } catch (RemoteException e) { 548 } 549 } 550 551 /** 552 * Sets the brightness of the backlights (screen, keyboard, button). 553 * <p> 554 * Requires the {@link android.Manifest.permission#DEVICE_POWER} permission. 555 * </p> 556 * 557 * @param brightness The brightness value from 0 to 255. 558 * 559 * {@hide} 560 */ 561 public void setBacklightBrightness(int brightness) { 562 try { 563 mService.setTemporaryScreenBrightnessSettingOverride(brightness); 564 } catch (RemoteException e) { 565 } 566 } 567 568 /** 569 * Returns true if the specified wake lock level is supported. 570 * 571 * @param level The wake lock level to check. 572 * @return True if the specified wake lock level is supported. 573 * 574 * {@hide} 575 */ 576 public boolean isWakeLockLevelSupported(int level) { 577 try { 578 return mService.isWakeLockLevelSupported(level); 579 } catch (RemoteException e) { 580 return false; 581 } 582 } 583 584 /** 585 * Returns true if the device is in an interactive state. 586 * <p> 587 * For historical reasons, the name of this method refers to the power state of 588 * the screen but it actually describes the overall interactive state of 589 * the device. This method has been replaced by {@link #isInteractive}. 590 * </p><p> 591 * The value returned by this method only indicates whether the device is 592 * in an interactive state which may have nothing to do with the screen being 593 * on or off. To determine the actual state of the screen, 594 * use {@link android.view.Display#getState}. 595 * </p> 596 * 597 * @return True if the device is in an interactive state. 598 * 599 * @deprecated Use {@link #isInteractive} instead. 600 */ 601 @Deprecated 602 public boolean isScreenOn() { 603 return isInteractive(); 604 } 605 606 /** 607 * Returns true if the device is in an interactive state. 608 * <p> 609 * When this method returns true, the device is awake and ready to interact 610 * with the user (although this is not a guarantee that the user is actively 611 * interacting with the device just this moment). The main screen is usually 612 * turned on while in this state. Certain features, such as the proximity 613 * sensor, may temporarily turn off the screen while still leaving the device in an 614 * interactive state. Note in particular that the device is still considered 615 * to be interactive while dreaming (since dreams can be interactive) but not 616 * when it is dozing or asleep. 617 * </p><p> 618 * When this method returns false, the device is dozing or asleep and must 619 * be awoken before it will become ready to interact with the user again. The 620 * main screen is usually turned off while in this state. Certain features, 621 * such as "ambient mode" may cause the main screen to remain on (albeit in a 622 * low power state) to display system-provided content while the device dozes. 623 * </p><p> 624 * The system will send a {@link android.content.Intent#ACTION_SCREEN_ON screen on} 625 * or {@link android.content.Intent#ACTION_SCREEN_OFF screen off} broadcast 626 * whenever the interactive state of the device changes. For historical reasons, 627 * the names of these broadcasts refer to the power state of the screen 628 * but they are actually sent in response to changes in the overall interactive 629 * state of the device, as described by this method. 630 * </p><p> 631 * Services may use the non-interactive state as a hint to conserve power 632 * since the user is not present. 633 * </p> 634 * 635 * @return True if the device is in an interactive state. 636 * 637 * @see android.content.Intent#ACTION_SCREEN_ON 638 * @see android.content.Intent#ACTION_SCREEN_OFF 639 */ 640 public boolean isInteractive() { 641 try { 642 return mService.isInteractive(); 643 } catch (RemoteException e) { 644 return false; 645 } 646 } 647 648 /** 649 * Reboot the device. Will not return if the reboot is successful. 650 * <p> 651 * Requires the {@link android.Manifest.permission#REBOOT} permission. 652 * </p> 653 * 654 * @param reason code to pass to the kernel (e.g., "recovery") to 655 * request special boot modes, or null. 656 */ 657 public void reboot(String reason) { 658 try { 659 mService.reboot(false, reason, true); 660 } catch (RemoteException e) { 661 } 662 } 663 664 /** 665 * A wake lock is a mechanism to indicate that your application needs 666 * to have the device stay on. 667 * <p> 668 * Any application using a WakeLock must request the {@code android.permission.WAKE_LOCK} 669 * permission in an {@code <uses-permission>} element of the application's manifest. 670 * Obtain a wake lock by calling {@link PowerManager#newWakeLock(int, String)}. 671 * </p><p> 672 * Call {@link #acquire()} to acquire the wake lock and force the device to stay 673 * on at the level that was requested when the wake lock was created. 674 * </p><p> 675 * Call {@link #release()} when you are done and don't need the lock anymore. 676 * It is very important to do this as soon as possible to avoid running down the 677 * device's battery excessively. 678 * </p> 679 */ 680 public final class WakeLock { 681 private final int mFlags; 682 private final String mTag; 683 private final String mPackageName; 684 private final IBinder mToken; 685 private int mCount; 686 private boolean mRefCounted = true; 687 private boolean mHeld; 688 private WorkSource mWorkSource; 689 690 private final Runnable mReleaser = new Runnable() { 691 public void run() { 692 release(); 693 } 694 }; 695 696 WakeLock(int flags, String tag, String packageName) { 697 mFlags = flags; 698 mTag = tag; 699 mPackageName = packageName; 700 mToken = new Binder(); 701 } 702 703 @Override 704 protected void finalize() throws Throwable { 705 synchronized (mToken) { 706 if (mHeld) { 707 Log.wtf(TAG, "WakeLock finalized while still held: " + mTag); 708 try { 709 mService.releaseWakeLock(mToken, 0); 710 } catch (RemoteException e) { 711 } 712 } 713 } 714 } 715 716 /** 717 * Sets whether this WakeLock is reference counted. 718 * <p> 719 * Wake locks are reference counted by default. If a wake lock is 720 * reference counted, then each call to {@link #acquire()} must be 721 * balanced by an equal number of calls to {@link #release()}. If a wake 722 * lock is not reference counted, then one call to {@link #release()} is 723 * sufficient to undo the effect of all previous calls to {@link #acquire()}. 724 * </p> 725 * 726 * @param value True to make the wake lock reference counted, false to 727 * make the wake lock non-reference counted. 728 */ 729 public void setReferenceCounted(boolean value) { 730 synchronized (mToken) { 731 mRefCounted = value; 732 } 733 } 734 735 /** 736 * Acquires the wake lock. 737 * <p> 738 * Ensures that the device is on at the level requested when 739 * the wake lock was created. 740 * </p> 741 */ 742 public void acquire() { 743 synchronized (mToken) { 744 acquireLocked(); 745 } 746 } 747 748 /** 749 * Acquires the wake lock with a timeout. 750 * <p> 751 * Ensures that the device is on at the level requested when 752 * the wake lock was created. The lock will be released after the given timeout 753 * expires. 754 * </p> 755 * 756 * @param timeout The timeout after which to release the wake lock, in milliseconds. 757 */ 758 public void acquire(long timeout) { 759 synchronized (mToken) { 760 acquireLocked(); 761 mHandler.postDelayed(mReleaser, timeout); 762 } 763 } 764 765 private void acquireLocked() { 766 if (!mRefCounted || mCount++ == 0) { 767 // Do this even if the wake lock is already thought to be held (mHeld == true) 768 // because non-reference counted wake locks are not always properly released. 769 // For example, the keyguard's wake lock might be forcibly released by the 770 // power manager without the keyguard knowing. A subsequent call to acquire 771 // should immediately acquire the wake lock once again despite never having 772 // been explicitly released by the keyguard. 773 mHandler.removeCallbacks(mReleaser); 774 try { 775 mService.acquireWakeLock(mToken, mFlags, mTag, mPackageName, mWorkSource); 776 } catch (RemoteException e) { 777 } 778 mHeld = true; 779 } 780 } 781 782 /** 783 * Releases the wake lock. 784 * <p> 785 * This method releases your claim to the CPU or screen being on. 786 * The screen may turn off shortly after you release the wake lock, or it may 787 * not if there are other wake locks still held. 788 * </p> 789 */ 790 public void release() { 791 release(0); 792 } 793 794 /** 795 * Releases the wake lock with flags to modify the release behavior. 796 * <p> 797 * This method releases your claim to the CPU or screen being on. 798 * The screen may turn off shortly after you release the wake lock, or it may 799 * not if there are other wake locks still held. 800 * </p> 801 * 802 * @param flags Combination of flag values to modify the release behavior. 803 * Currently only {@link #WAIT_FOR_PROXIMITY_NEGATIVE} is supported. 804 * 805 * {@hide} 806 */ 807 public void release(int flags) { 808 synchronized (mToken) { 809 if (!mRefCounted || --mCount == 0) { 810 mHandler.removeCallbacks(mReleaser); 811 if (mHeld) { 812 try { 813 mService.releaseWakeLock(mToken, flags); 814 } catch (RemoteException e) { 815 } 816 mHeld = false; 817 } 818 } 819 if (mCount < 0) { 820 throw new RuntimeException("WakeLock under-locked " + mTag); 821 } 822 } 823 } 824 825 /** 826 * Returns true if the wake lock has been acquired but not yet released. 827 * 828 * @return True if the wake lock is held. 829 */ 830 public boolean isHeld() { 831 synchronized (mToken) { 832 return mHeld; 833 } 834 } 835 836 /** 837 * Sets the work source associated with the wake lock. 838 * <p> 839 * The work source is used to determine on behalf of which application 840 * the wake lock is being held. This is useful in the case where a 841 * service is performing work on behalf of an application so that the 842 * cost of that work can be accounted to the application. 843 * </p> 844 * 845 * @param ws The work source, or null if none. 846 */ 847 public void setWorkSource(WorkSource ws) { 848 synchronized (mToken) { 849 if (ws != null && ws.size() == 0) { 850 ws = null; 851 } 852 853 final boolean changed; 854 if (ws == null) { 855 changed = mWorkSource != null; 856 mWorkSource = null; 857 } else if (mWorkSource == null) { 858 changed = true; 859 mWorkSource = new WorkSource(ws); 860 } else { 861 changed = mWorkSource.diff(ws); 862 if (changed) { 863 mWorkSource.set(ws); 864 } 865 } 866 867 if (changed && mHeld) { 868 try { 869 mService.updateWakeLockWorkSource(mToken, mWorkSource); 870 } catch (RemoteException e) { 871 } 872 } 873 } 874 } 875 876 @Override 877 public String toString() { 878 synchronized (mToken) { 879 return "WakeLock{" 880 + Integer.toHexString(System.identityHashCode(this)) 881 + " held=" + mHeld + ", refCount=" + mCount + "}"; 882 } 883 } 884 } 885} 886