CameraManager.java revision feb50af361e4305a25758966b6b5df2738c00259
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 throw new IllegalStateException("Failed to setup camera vendor tags", 89 e.asChecked()); 90 } 91 92 try { 93 mCameraService.addListener(new CameraServiceListener()); 94 } catch(CameraRuntimeException e) { 95 throw new IllegalStateException("Failed to register a camera service listener", 96 e.asChecked()); 97 } catch (RemoteException e) { 98 // impossible 99 } 100 } 101 102 /** 103 * Return the list of currently connected camera devices by 104 * identifier. 105 * 106 * <p>Non-removable cameras use integers starting at 0 for their 107 * identifiers, while removable cameras have a unique identifier for each 108 * individual device, even if they are the same model.</p> 109 * 110 * @return The list of currently connected camera devices. 111 */ 112 public String[] getCameraIdList() throws CameraAccessException { 113 synchronized (mLock) { 114 try { 115 return getOrCreateDeviceIdListLocked().toArray(new String[0]); 116 } catch(CameraAccessException e) { 117 // this should almost never happen, except if mediaserver crashes 118 throw new IllegalStateException( 119 "Failed to query camera service for device ID list", e); 120 } 121 } 122 } 123 124 /** 125 * Register a listener to be notified about camera device availability. 126 * 127 * <p>Registering the same listener again will replace the handler with the 128 * new one provided.</p> 129 * 130 * @param listener The new listener to send camera availability notices to 131 * @param handler The handler on which the listener should be invoked, or 132 * {@code null} to use the current thread's {@link android.os.Looper looper}. 133 */ 134 public void addAvailabilityListener(AvailabilityListener listener, Handler handler) { 135 if (handler == null) { 136 Looper looper = Looper.myLooper(); 137 if (looper == null) { 138 throw new IllegalArgumentException( 139 "No handler given, and current thread has no looper!"); 140 } 141 handler = new Handler(looper); 142 } 143 144 synchronized (mLock) { 145 mListenerMap.put(listener, handler); 146 } 147 } 148 149 /** 150 * Remove a previously-added listener; the listener will no longer receive 151 * connection and disconnection callbacks. 152 * 153 * <p>Removing a listener that isn't registered has no effect.</p> 154 * 155 * @param listener The listener to remove from the notification list 156 */ 157 public void removeAvailabilityListener(AvailabilityListener listener) { 158 synchronized (mLock) { 159 mListenerMap.remove(listener); 160 } 161 } 162 163 /** 164 * <p>Query the capabilities of a camera device. These capabilities are 165 * immutable for a given camera.</p> 166 * 167 * @param cameraId The id of the camera device to query 168 * @return The properties of the given camera 169 * 170 * @throws IllegalArgumentException if the cameraId does not match any 171 * currently connected camera device. 172 * @throws CameraAccessException if the camera is disabled by device policy. 173 * @throws SecurityException if the application does not have permission to 174 * access the camera 175 * 176 * @see #getCameraIdList 177 * @see android.app.admin.DevicePolicyManager#setCameraDisabled 178 */ 179 public CameraCharacteristics getCameraCharacteristics(String cameraId) 180 throws CameraAccessException { 181 182 synchronized (mLock) { 183 if (!getOrCreateDeviceIdListLocked().contains(cameraId)) { 184 throw new IllegalArgumentException(String.format("Camera id %s does not match any" + 185 " currently connected camera device", cameraId)); 186 } 187 } 188 189 CameraMetadataNative info = new CameraMetadataNative(); 190 try { 191 mCameraService.getCameraCharacteristics(Integer.valueOf(cameraId), info); 192 } catch(CameraRuntimeException e) { 193 throw e.asChecked(); 194 } catch(RemoteException e) { 195 // impossible 196 return null; 197 } 198 return new CameraCharacteristics(info); 199 } 200 201 /** 202 * Open a connection to a camera with the given ID. Use 203 * {@link #getCameraIdList} to get the list of available camera 204 * devices. Note that even if an id is listed, open may fail if the device 205 * is disconnected between the calls to {@link #getCameraIdList} and 206 * {@link #openCamera}. 207 * 208 * @param cameraId The unique identifier of the camera device to open 209 * @param listener The listener for the camera. Must not be null. 210 * @param handler The handler to call the listener on. Must not be null. 211 * 212 * @throws CameraAccessException if the camera is disabled by device policy, 213 * or too many camera devices are already open, or the cameraId does not match 214 * any currently available camera device. 215 * 216 * @throws SecurityException if the application does not have permission to 217 * access the camera 218 * @throws IllegalArgumentException if listener or handler is null. 219 * 220 * @see #getCameraIdList 221 * @see android.app.admin.DevicePolicyManager#setCameraDisabled 222 */ 223 private void openCameraDeviceUserAsync(String cameraId, 224 CameraDevice.StateListener listener, Handler handler) 225 throws CameraAccessException { 226 try { 227 228 synchronized (mLock) { 229 230 ICameraDeviceUser cameraUser; 231 232 android.hardware.camera2.impl.CameraDevice device = 233 new android.hardware.camera2.impl.CameraDevice( 234 cameraId, 235 listener, 236 handler); 237 238 BinderHolder holder = new BinderHolder(); 239 240 ICameraDeviceCallbacks callbacks = device.getCallbacks(); 241 int id = Integer.parseInt(cameraId); 242 try { 243 mCameraService.connectDevice(callbacks, id, mContext.getPackageName(), 244 USE_CALLING_UID, holder); 245 cameraUser = ICameraDeviceUser.Stub.asInterface(holder.getBinder()); 246 } catch (CameraRuntimeException e) { 247 if (e.getReason() == CameraAccessException.CAMERA_DEPRECATED_HAL) { 248 // Use legacy camera implementation for HAL1 devices 249 Log.i(TAG, "Using legacy camera HAL."); 250 cameraUser = CameraDeviceUserShim.connectBinderShim(callbacks, id); 251 } else { 252 // Rethrow otherwise 253 throw e; 254 } 255 } 256 257 // TODO: factor out listener to be non-nested, then move setter to constructor 258 // For now, calling setRemoteDevice will fire initial 259 // onOpened/onUnconfigured callbacks. 260 device.setRemoteDevice(cameraUser); 261 } 262 263 } catch (NumberFormatException e) { 264 throw new IllegalArgumentException("Expected cameraId to be numeric, but it was: " 265 + cameraId); 266 } catch (CameraRuntimeException e) { 267 throw e.asChecked(); 268 } catch (RemoteException e) { 269 // impossible 270 } 271 } 272 273 /** 274 * Open a connection to a camera with the given ID. 275 * 276 * <p>Use {@link #getCameraIdList} to get the list of available camera 277 * devices. Note that even if an id is listed, open may fail if the device 278 * is disconnected between the calls to {@link #getCameraIdList} and 279 * {@link #openCamera}.</p> 280 * 281 * <p>If the camera successfully opens after this function call returns, 282 * {@link CameraDevice.StateListener#onOpened} will be invoked with the 283 * newly opened {@link CameraDevice} in the unconfigured state.</p> 284 * 285 * <p>If the camera becomes disconnected during initialization 286 * after this function call returns, 287 * {@link CameraDevice.StateListener#onDisconnected} with a 288 * {@link CameraDevice} in the disconnected state (and 289 * {@link CameraDevice.StateListener#onOpened} will be skipped).</p> 290 * 291 * <p>If the camera fails to initialize after this function call returns, 292 * {@link CameraDevice.StateListener#onError} will be invoked with a 293 * {@link CameraDevice} in the error state (and 294 * {@link CameraDevice.StateListener#onOpened} will be skipped).</p> 295 * 296 * @param cameraId 297 * The unique identifier of the camera device to open 298 * @param listener 299 * The listener which is invoked once the camera is opened 300 * @param handler 301 * The handler on which the listener should be invoked, or 302 * {@code null} to use the current thread's {@link android.os.Looper looper}. 303 * 304 * @throws CameraAccessException if the camera is disabled by device policy, 305 * or the camera has become or was disconnected. 306 * 307 * @throws IllegalArgumentException if cameraId or the listener was null, 308 * or the cameraId does not match any currently or previously available 309 * camera device. 310 * 311 * @throws SecurityException if the application does not have permission to 312 * access the camera 313 * 314 * @see #getCameraIdList 315 * @see android.app.admin.DevicePolicyManager#setCameraDisabled 316 */ 317 public void openCamera(String cameraId, final CameraDevice.StateListener listener, 318 Handler handler) 319 throws CameraAccessException { 320 321 if (cameraId == null) { 322 throw new IllegalArgumentException("cameraId was null"); 323 } else if (listener == null) { 324 throw new IllegalArgumentException("listener was null"); 325 } else if (handler == null) { 326 if (Looper.myLooper() != null) { 327 handler = new Handler(); 328 } else { 329 throw new IllegalArgumentException( 330 "Looper doesn't exist in the calling thread"); 331 } 332 } 333 334 openCameraDeviceUserAsync(cameraId, listener, handler); 335 } 336 337 /** 338 * Interface for listening to camera devices becoming available or 339 * unavailable. 340 * 341 * <p>Cameras become available when they are no longer in use, or when a new 342 * removable camera is connected. They become unavailable when some 343 * application or service starts using a camera, or when a removable camera 344 * is disconnected.</p> 345 * 346 * @see addAvailabilityListener 347 */ 348 public static abstract class AvailabilityListener { 349 350 /** 351 * A new camera has become available to use. 352 * 353 * <p>The default implementation of this method does nothing.</p> 354 * 355 * @param cameraId The unique identifier of the new camera. 356 */ 357 public void onCameraAvailable(String cameraId) { 358 // default empty implementation 359 } 360 361 /** 362 * A previously-available camera has become unavailable for use. 363 * 364 * <p>If an application had an active CameraDevice instance for the 365 * now-disconnected camera, that application will receive a 366 * {@link CameraDevice.StateListener#onDisconnected disconnection error}.</p> 367 * 368 * <p>The default implementation of this method does nothing.</p> 369 * 370 * @param cameraId The unique identifier of the disconnected camera. 371 */ 372 public void onCameraUnavailable(String cameraId) { 373 // default empty implementation 374 } 375 } 376 377 private ArrayList<String> getOrCreateDeviceIdListLocked() throws CameraAccessException { 378 if (mDeviceIdList == null) { 379 int numCameras = 0; 380 381 try { 382 numCameras = mCameraService.getNumberOfCameras(); 383 } catch(CameraRuntimeException e) { 384 throw e.asChecked(); 385 } catch (RemoteException e) { 386 // impossible 387 return null; 388 } 389 390 mDeviceIdList = new ArrayList<String>(); 391 CameraMetadataNative info = new CameraMetadataNative(); 392 for (int i = 0; i < numCameras; ++i) { 393 // Non-removable cameras use integers starting at 0 for their 394 // identifiers 395 boolean isDeviceSupported = false; 396 try { 397 mCameraService.getCameraCharacteristics(i, info); 398 if (!info.isEmpty()) { 399 isDeviceSupported = true; 400 } else { 401 throw new AssertionError("Expected to get non-empty characteristics"); 402 } 403 } catch(IllegalArgumentException e) { 404 // Got a BAD_VALUE from service, meaning that this 405 // device is not supported. 406 } catch(CameraRuntimeException e) { 407 throw e.asChecked(); 408 } catch(RemoteException e) { 409 // impossible 410 } 411 412 if (isDeviceSupported) { 413 mDeviceIdList.add(String.valueOf(i)); 414 } 415 } 416 417 } 418 return mDeviceIdList; 419 } 420 421 // TODO: this class needs unit tests 422 // TODO: extract class into top level 423 private class CameraServiceListener extends ICameraServiceListener.Stub { 424 425 // Keep up-to-date with ICameraServiceListener.h 426 427 // Device physically unplugged 428 public static final int STATUS_NOT_PRESENT = 0; 429 // Device physically has been plugged in 430 // and the camera can be used exclusively 431 public static final int STATUS_PRESENT = 1; 432 // Device physically has been plugged in 433 // but it will not be connect-able until enumeration is complete 434 public static final int STATUS_ENUMERATING = 2; 435 // Camera is in use by another app and cannot be used exclusively 436 public static final int STATUS_NOT_AVAILABLE = 0x80000000; 437 438 // Camera ID -> Status map 439 private final ArrayMap<String, Integer> mDeviceStatus = new ArrayMap<String, Integer>(); 440 441 private static final String TAG = "CameraServiceListener"; 442 443 @Override 444 public IBinder asBinder() { 445 return this; 446 } 447 448 private boolean isAvailable(int status) { 449 switch (status) { 450 case STATUS_PRESENT: 451 return true; 452 default: 453 return false; 454 } 455 } 456 457 private boolean validStatus(int status) { 458 switch (status) { 459 case STATUS_NOT_PRESENT: 460 case STATUS_PRESENT: 461 case STATUS_ENUMERATING: 462 case STATUS_NOT_AVAILABLE: 463 return true; 464 default: 465 return false; 466 } 467 } 468 469 @Override 470 public void onStatusChanged(int status, int cameraId) throws RemoteException { 471 synchronized(CameraManager.this.mLock) { 472 473 Log.v(TAG, 474 String.format("Camera id %d has status changed to 0x%x", cameraId, status)); 475 476 final String id = String.valueOf(cameraId); 477 478 if (!validStatus(status)) { 479 Log.e(TAG, String.format("Ignoring invalid device %d status 0x%x", cameraId, 480 status)); 481 return; 482 } 483 484 Integer oldStatus = mDeviceStatus.put(id, status); 485 486 if (oldStatus != null && oldStatus == status) { 487 Log.v(TAG, String.format( 488 "Device status changed to 0x%x, which is what it already was", 489 status)); 490 return; 491 } 492 493 // TODO: consider abstracting out this state minimization + transition 494 // into a separate 495 // more easily testable class 496 // i.e. (new State()).addState(STATE_AVAILABLE) 497 // .addState(STATE_NOT_AVAILABLE) 498 // .addTransition(STATUS_PRESENT, STATE_AVAILABLE), 499 // .addTransition(STATUS_NOT_PRESENT, STATE_NOT_AVAILABLE) 500 // .addTransition(STATUS_ENUMERATING, STATE_NOT_AVAILABLE); 501 // .addTransition(STATUS_NOT_AVAILABLE, STATE_NOT_AVAILABLE); 502 503 // Translate all the statuses to either 'available' or 'not available' 504 // available -> available => no new update 505 // not available -> not available => no new update 506 if (oldStatus != null && isAvailable(status) == isAvailable(oldStatus)) { 507 508 Log.v(TAG, 509 String.format( 510 "Device status was previously available (%d), " + 511 " and is now again available (%d)" + 512 "so no new client visible update will be sent", 513 isAvailable(status), isAvailable(status))); 514 return; 515 } 516 517 final int listenerCount = mListenerMap.size(); 518 for (int i = 0; i < listenerCount; i++) { 519 Handler handler = mListenerMap.valueAt(i); 520 final AvailabilityListener listener = mListenerMap.keyAt(i); 521 if (isAvailable(status)) { 522 handler.post( 523 new Runnable() { 524 @Override 525 public void run() { 526 listener.onCameraAvailable(id); 527 } 528 }); 529 } else { 530 handler.post( 531 new Runnable() { 532 @Override 533 public void run() { 534 listener.onCameraUnavailable(id); 535 } 536 }); 537 } 538 } // for 539 } // synchronized 540 } // onStatusChanged 541 } // CameraServiceListener 542} // CameraManager 543