CameraManager.java revision b6a781066e6b0f2578cafefdc61c9ba18c0efc2e
1/* 2 * Copyright (C) 2013 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.hardware.camera2; 18 19import android.content.Context; 20import android.hardware.ICameraService; 21import android.hardware.ICameraServiceListener; 22import android.hardware.camera2.impl.CameraMetadataNative; 23import android.hardware.camera2.legacy.CameraDeviceUserShim; 24import android.hardware.camera2.utils.CameraBinderDecorator; 25import android.hardware.camera2.utils.CameraRuntimeException; 26import android.hardware.camera2.utils.BinderHolder; 27import android.os.IBinder; 28import android.os.Handler; 29import android.os.Looper; 30import android.os.RemoteException; 31import android.os.ServiceManager; 32import android.util.Log; 33import android.util.ArrayMap; 34 35import java.util.ArrayList; 36 37/** 38 * <p>An interface for iterating, listing, and connecting to 39 * {@link CameraDevice CameraDevices}.</p> 40 * 41 * <p>You can get an instance of this class by calling 42 * {@link android.content.Context#getSystemService(String) Context.getSystemService()}.</p> 43 * 44 * <pre>CameraManager manager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);</pre> 45 * 46 * <p>For more details about communicating with camera devices, read the Camera 47 * developer guide or the {@link android.hardware.camera2 camera2} 48 * package documentation.</p> 49 */ 50public final class CameraManager { 51 52 private static final String TAG = "CameraManager"; 53 54 /** 55 * This should match the ICameraService definition 56 */ 57 private static final String CAMERA_SERVICE_BINDER_NAME = "media.camera"; 58 private static final int USE_CALLING_UID = -1; 59 60 private final ICameraService mCameraService; 61 private ArrayList<String> mDeviceIdList; 62 63 private final ArrayMap<AvailabilityListener, Handler> mListenerMap = 64 new ArrayMap<AvailabilityListener, Handler>(); 65 66 private final Context mContext; 67 private final Object mLock = new Object(); 68 69 /** 70 * @hide 71 */ 72 public CameraManager(Context context) { 73 mContext = context; 74 75 IBinder cameraServiceBinder = ServiceManager.getService(CAMERA_SERVICE_BINDER_NAME); 76 ICameraService cameraServiceRaw = ICameraService.Stub.asInterface(cameraServiceBinder); 77 78 /** 79 * Wrap the camera service in a decorator which automatically translates return codes 80 * into exceptions, and RemoteExceptions into other exceptions. 81 */ 82 mCameraService = CameraBinderDecorator.newInstance(cameraServiceRaw); 83 84 try { 85 CameraBinderDecorator.throwOnError( 86 CameraMetadataNative.nativeSetupGlobalVendorTagDescriptor()); 87 } catch (CameraRuntimeException e) { 88 handleRecoverableSetupErrors(e, "Failed to set up vendor tags"); 89 } 90 91 try { 92 mCameraService.addListener(new CameraServiceListener()); 93 } catch(CameraRuntimeException e) { 94 throw new IllegalStateException("Failed to register a camera service listener", 95 e.asChecked()); 96 } catch (RemoteException e) { 97 // impossible 98 } 99 } 100 101 /** 102 * Return the list of currently connected camera devices by 103 * identifier. 104 * 105 * <p>Non-removable cameras use integers starting at 0 for their 106 * identifiers, while removable cameras have a unique identifier for each 107 * individual device, even if they are the same model.</p> 108 * 109 * @return The list of currently connected camera devices. 110 */ 111 public String[] getCameraIdList() throws CameraAccessException { 112 synchronized (mLock) { 113 try { 114 return getOrCreateDeviceIdListLocked().toArray(new String[0]); 115 } catch(CameraAccessException e) { 116 // this should almost never happen, except if mediaserver crashes 117 throw new IllegalStateException( 118 "Failed to query camera service for device ID list", e); 119 } 120 } 121 } 122 123 /** 124 * Register a listener to be notified about camera device availability. 125 * 126 * <p>Registering the same listener again will replace the handler with the 127 * new one provided.</p> 128 * 129 * @param listener The new listener to send camera availability notices to 130 * @param handler The handler on which the listener should be invoked, or 131 * {@code null} to use the current thread's {@link android.os.Looper looper}. 132 */ 133 public void addAvailabilityListener(AvailabilityListener listener, Handler handler) { 134 if (handler == null) { 135 Looper looper = Looper.myLooper(); 136 if (looper == null) { 137 throw new IllegalArgumentException( 138 "No handler given, and current thread has no looper!"); 139 } 140 handler = new Handler(looper); 141 } 142 143 synchronized (mLock) { 144 mListenerMap.put(listener, handler); 145 } 146 } 147 148 /** 149 * Remove a previously-added listener; the listener will no longer receive 150 * connection and disconnection callbacks. 151 * 152 * <p>Removing a listener that isn't registered has no effect.</p> 153 * 154 * @param listener The listener to remove from the notification list 155 */ 156 public void removeAvailabilityListener(AvailabilityListener listener) { 157 synchronized (mLock) { 158 mListenerMap.remove(listener); 159 } 160 } 161 162 /** 163 * <p>Query the capabilities of a camera device. These capabilities are 164 * immutable for a given camera.</p> 165 * 166 * @param cameraId The id of the camera device to query 167 * @return The properties of the given camera 168 * 169 * @throws IllegalArgumentException if the cameraId does not match any 170 * currently connected camera device. 171 * @throws CameraAccessException if the camera is disabled by device policy. 172 * @throws SecurityException if the application does not have permission to 173 * access the camera 174 * 175 * @see #getCameraIdList 176 * @see android.app.admin.DevicePolicyManager#setCameraDisabled 177 */ 178 public CameraCharacteristics getCameraCharacteristics(String cameraId) 179 throws CameraAccessException { 180 181 synchronized (mLock) { 182 if (!getOrCreateDeviceIdListLocked().contains(cameraId)) { 183 throw new IllegalArgumentException(String.format("Camera id %s does not match any" + 184 " currently connected camera device", cameraId)); 185 } 186 } 187 188 CameraMetadataNative info = new CameraMetadataNative(); 189 try { 190 mCameraService.getCameraCharacteristics(Integer.valueOf(cameraId), info); 191 } catch(CameraRuntimeException e) { 192 throw e.asChecked(); 193 } catch(RemoteException e) { 194 // impossible 195 return null; 196 } 197 return new CameraCharacteristics(info); 198 } 199 200 /** 201 * Helper for openning a connection to a camera with the given ID. 202 * 203 * @param cameraId The unique identifier of the camera device to open 204 * @param listener The listener for the camera. Must not be null. 205 * @param handler The handler to call the listener on. Must not be null. 206 * 207 * @throws CameraAccessException if the camera is disabled by device policy, 208 * or too many camera devices are already open, or the cameraId does not match 209 * any currently available camera device. 210 * 211 * @throws SecurityException if the application does not have permission to 212 * access the camera 213 * @throws IllegalArgumentException if listener or handler is null. 214 * @return A handle to the newly-created camera device. 215 * 216 * @see #getCameraIdList 217 * @see android.app.admin.DevicePolicyManager#setCameraDisabled 218 */ 219 private CameraDevice openCameraDeviceUserAsync(String cameraId, 220 CameraDevice.StateListener listener, Handler handler) 221 throws CameraAccessException { 222 CameraDevice device = null; 223 try { 224 225 synchronized (mLock) { 226 227 ICameraDeviceUser cameraUser; 228 229 android.hardware.camera2.impl.CameraDevice deviceImpl = 230 new android.hardware.camera2.impl.CameraDevice( 231 cameraId, 232 listener, 233 handler); 234 235 BinderHolder holder = new BinderHolder(); 236 237 ICameraDeviceCallbacks callbacks = deviceImpl.getCallbacks(); 238 int id = Integer.parseInt(cameraId); 239 try { 240 mCameraService.connectDevice(callbacks, id, mContext.getPackageName(), 241 USE_CALLING_UID, holder); 242 cameraUser = ICameraDeviceUser.Stub.asInterface(holder.getBinder()); 243 } catch (CameraRuntimeException e) { 244 if (e.getReason() == CameraAccessException.CAMERA_DEPRECATED_HAL) { 245 // Use legacy camera implementation for HAL1 devices 246 Log.i(TAG, "Using legacy camera HAL."); 247 cameraUser = CameraDeviceUserShim.connectBinderShim(callbacks, id); 248 } else { 249 // Rethrow otherwise 250 throw e; 251 } 252 } 253 254 // TODO: factor out listener to be non-nested, then move setter to constructor 255 // For now, calling setRemoteDevice will fire initial 256 // onOpened/onUnconfigured callbacks. 257 deviceImpl.setRemoteDevice(cameraUser); 258 device = deviceImpl; 259 } 260 261 } catch (NumberFormatException e) { 262 throw new IllegalArgumentException("Expected cameraId to be numeric, but it was: " 263 + cameraId); 264 } catch (CameraRuntimeException e) { 265 throw e.asChecked(); 266 } catch (RemoteException e) { 267 // impossible 268 } 269 return device; 270 } 271 272 /** 273 * Open a connection to a camera with the given ID. 274 * 275 * <p>Use {@link #getCameraIdList} to get the list of available camera 276 * devices. Note that even if an id is listed, open may fail if the device 277 * is disconnected between the calls to {@link #getCameraIdList} and 278 * {@link #openCamera}.</p> 279 * 280 * <p>Once the camera is successfully opened, {@link CameraDevice.StateListener#onOpened} will 281 * be invoked with the newly opened {@link CameraDevice}. The camera device can then be set up 282 * for operation by calling {@link CameraDevice#createCaptureSession} and 283 * {@link CameraDevice#createCaptureRequest}</p> 284 * 285 * <!-- 286 * <p>Since the camera device will be opened asynchronously, any asynchronous operations done 287 * on the returned CameraDevice instance will be queued up until the device startup has 288 * completed and the listener's {@link CameraDevice.StateListener#onOpened onOpened} method is 289 * called. The pending operations are then processed in order.</p> 290 * --> 291 * <p>If the camera becomes disconnected during initialization 292 * after this function call returns, 293 * {@link CameraDevice.StateListener#onDisconnected} with a 294 * {@link CameraDevice} in the disconnected state (and 295 * {@link CameraDevice.StateListener#onOpened} will be skipped).</p> 296 * 297 * <p>If opening the camera device fails, then the device listener's 298 * {@link CameraDevice.StateListener#onError onError} method will be called, and subsequent 299 * calls on the camera device will throw an {@link IllegalStateException}.</p> 300 * 301 * @param cameraId 302 * The unique identifier of the camera device to open 303 * @param listener 304 * The listener which is invoked once the camera is opened 305 * @param handler 306 * The handler on which the listener should be invoked, or 307 * {@code null} to use the current thread's {@link android.os.Looper looper}. 308 * 309 * @throws CameraAccessException if the camera is disabled by device policy, 310 * or the camera has become or was disconnected. 311 * 312 * @throws IllegalArgumentException if cameraId or the listener was null, 313 * or the cameraId does not match any currently or previously available 314 * camera device. 315 * 316 * @throws SecurityException if the application does not have permission to 317 * access the camera 318 * 319 * @see #getCameraIdList 320 * @see android.app.admin.DevicePolicyManager#setCameraDisabled 321 */ 322 public void openCamera(String cameraId, final CameraDevice.StateListener listener, 323 Handler handler) 324 throws CameraAccessException { 325 326 if (cameraId == null) { 327 throw new IllegalArgumentException("cameraId was null"); 328 } else if (listener == null) { 329 throw new IllegalArgumentException("listener was null"); 330 } else if (handler == null) { 331 if (Looper.myLooper() != null) { 332 handler = new Handler(); 333 } else { 334 throw new IllegalArgumentException( 335 "Looper doesn't exist in the calling thread"); 336 } 337 } 338 339 openCameraDeviceUserAsync(cameraId, listener, handler); 340 } 341 342 /** 343 * Interface for listening to camera devices becoming available or 344 * unavailable. 345 * 346 * <p>Cameras become available when they are no longer in use, or when a new 347 * removable camera is connected. They become unavailable when some 348 * application or service starts using a camera, or when a removable camera 349 * is disconnected.</p> 350 * 351 * @see addAvailabilityListener 352 */ 353 public static abstract class AvailabilityListener { 354 355 /** 356 * A new camera has become available to use. 357 * 358 * <p>The default implementation of this method does nothing.</p> 359 * 360 * @param cameraId The unique identifier of the new camera. 361 */ 362 public void onCameraAvailable(String cameraId) { 363 // default empty implementation 364 } 365 366 /** 367 * A previously-available camera has become unavailable for use. 368 * 369 * <p>If an application had an active CameraDevice instance for the 370 * now-disconnected camera, that application will receive a 371 * {@link CameraDevice.StateListener#onDisconnected disconnection error}.</p> 372 * 373 * <p>The default implementation of this method does nothing.</p> 374 * 375 * @param cameraId The unique identifier of the disconnected camera. 376 */ 377 public void onCameraUnavailable(String cameraId) { 378 // default empty implementation 379 } 380 } 381 382 private ArrayList<String> getOrCreateDeviceIdListLocked() throws CameraAccessException { 383 if (mDeviceIdList == null) { 384 int numCameras = 0; 385 386 try { 387 numCameras = mCameraService.getNumberOfCameras(); 388 } catch(CameraRuntimeException e) { 389 throw e.asChecked(); 390 } catch (RemoteException e) { 391 // impossible 392 return null; 393 } 394 395 mDeviceIdList = new ArrayList<String>(); 396 CameraMetadataNative info = new CameraMetadataNative(); 397 for (int i = 0; i < numCameras; ++i) { 398 // Non-removable cameras use integers starting at 0 for their 399 // identifiers 400 boolean isDeviceSupported = false; 401 try { 402 mCameraService.getCameraCharacteristics(i, info); 403 if (!info.isEmpty()) { 404 isDeviceSupported = true; 405 } else { 406 throw new AssertionError("Expected to get non-empty characteristics"); 407 } 408 } catch(IllegalArgumentException e) { 409 // Got a BAD_VALUE from service, meaning that this 410 // device is not supported. 411 } catch(CameraRuntimeException e) { 412 throw e.asChecked(); 413 } catch(RemoteException e) { 414 // impossible 415 } 416 417 if (isDeviceSupported) { 418 mDeviceIdList.add(String.valueOf(i)); 419 } 420 } 421 422 } 423 return mDeviceIdList; 424 } 425 426 private void handleRecoverableSetupErrors(CameraRuntimeException e, String msg) { 427 int problem = e.getReason(); 428 switch (problem) { 429 case CameraAccessException.CAMERA_DISCONNECTED: 430 String errorMsg = CameraAccessException.getDefaultMessage(problem); 431 Log.w(TAG, msg + ": " + errorMsg); 432 break; 433 default: 434 throw new IllegalStateException(msg, e.asChecked()); 435 } 436 } 437 438 // TODO: this class needs unit tests 439 // TODO: extract class into top level 440 private class CameraServiceListener extends ICameraServiceListener.Stub { 441 442 // Keep up-to-date with ICameraServiceListener.h 443 444 // Device physically unplugged 445 public static final int STATUS_NOT_PRESENT = 0; 446 // Device physically has been plugged in 447 // and the camera can be used exclusively 448 public static final int STATUS_PRESENT = 1; 449 // Device physically has been plugged in 450 // but it will not be connect-able until enumeration is complete 451 public static final int STATUS_ENUMERATING = 2; 452 // Camera is in use by another app and cannot be used exclusively 453 public static final int STATUS_NOT_AVAILABLE = 0x80000000; 454 455 // Camera ID -> Status map 456 private final ArrayMap<String, Integer> mDeviceStatus = new ArrayMap<String, Integer>(); 457 458 private static final String TAG = "CameraServiceListener"; 459 460 @Override 461 public IBinder asBinder() { 462 return this; 463 } 464 465 private boolean isAvailable(int status) { 466 switch (status) { 467 case STATUS_PRESENT: 468 return true; 469 default: 470 return false; 471 } 472 } 473 474 private boolean validStatus(int status) { 475 switch (status) { 476 case STATUS_NOT_PRESENT: 477 case STATUS_PRESENT: 478 case STATUS_ENUMERATING: 479 case STATUS_NOT_AVAILABLE: 480 return true; 481 default: 482 return false; 483 } 484 } 485 486 @Override 487 public void onStatusChanged(int status, int cameraId) throws RemoteException { 488 synchronized(CameraManager.this.mLock) { 489 490 Log.v(TAG, 491 String.format("Camera id %d has status changed to 0x%x", cameraId, status)); 492 493 final String id = String.valueOf(cameraId); 494 495 if (!validStatus(status)) { 496 Log.e(TAG, String.format("Ignoring invalid device %d status 0x%x", cameraId, 497 status)); 498 return; 499 } 500 501 Integer oldStatus = mDeviceStatus.put(id, status); 502 503 if (oldStatus != null && oldStatus == status) { 504 Log.v(TAG, String.format( 505 "Device status changed to 0x%x, which is what it already was", 506 status)); 507 return; 508 } 509 510 // TODO: consider abstracting out this state minimization + transition 511 // into a separate 512 // more easily testable class 513 // i.e. (new State()).addState(STATE_AVAILABLE) 514 // .addState(STATE_NOT_AVAILABLE) 515 // .addTransition(STATUS_PRESENT, STATE_AVAILABLE), 516 // .addTransition(STATUS_NOT_PRESENT, STATE_NOT_AVAILABLE) 517 // .addTransition(STATUS_ENUMERATING, STATE_NOT_AVAILABLE); 518 // .addTransition(STATUS_NOT_AVAILABLE, STATE_NOT_AVAILABLE); 519 520 // Translate all the statuses to either 'available' or 'not available' 521 // available -> available => no new update 522 // not available -> not available => no new update 523 if (oldStatus != null && isAvailable(status) == isAvailable(oldStatus)) { 524 525 Log.v(TAG, 526 String.format( 527 "Device status was previously available (%d), " + 528 " and is now again available (%d)" + 529 "so no new client visible update will be sent", 530 isAvailable(status), isAvailable(status))); 531 return; 532 } 533 534 final int listenerCount = mListenerMap.size(); 535 for (int i = 0; i < listenerCount; i++) { 536 Handler handler = mListenerMap.valueAt(i); 537 final AvailabilityListener listener = mListenerMap.keyAt(i); 538 if (isAvailable(status)) { 539 handler.post( 540 new Runnable() { 541 @Override 542 public void run() { 543 listener.onCameraAvailable(id); 544 } 545 }); 546 } else { 547 handler.post( 548 new Runnable() { 549 @Override 550 public void run() { 551 listener.onCameraUnavailable(id); 552 } 553 }); 554 } 555 } // for 556 } // synchronized 557 } // onStatusChanged 558 } // CameraServiceListener 559} // CameraManager 560