1 /* 2 * Copyright (C) 2014 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 17 package android.hardware.camera2.legacy; 18 19 import android.hardware.camera2.impl.CameraDeviceImpl; 20 import android.hardware.camera2.impl.CameraMetadataNative; 21 import android.os.Handler; 22 import android.util.Log; 23 24 /** 25 * Emulates a the state of a single Camera2 device. 26 * 27 * <p> 28 * This class acts as the state machine for a camera device. Valid state transitions are given 29 * in the table below: 30 * </p> 31 * 32 * <ul> 33 * <li>{@code UNCONFIGURED -> CONFIGURING}</li> 34 * <li>{@code CONFIGURING -> IDLE}</li> 35 * <li>{@code IDLE -> CONFIGURING}</li> 36 * <li>{@code IDLE -> CAPTURING}</li> 37 * <li>{@code IDLE -> IDLE}</li> 38 * <li>{@code CAPTURING -> IDLE}</li> 39 * <li>{@code ANY -> ERROR}</li> 40 * </ul> 41 */ 42 public class CameraDeviceState { 43 private static final String TAG = "CameraDeviceState"; 44 private static final boolean DEBUG = false; 45 46 private static final int STATE_ERROR = 0; 47 private static final int STATE_UNCONFIGURED = 1; 48 private static final int STATE_CONFIGURING = 2; 49 private static final int STATE_IDLE = 3; 50 private static final int STATE_CAPTURING = 4; 51 52 private static final String[] sStateNames = { "ERROR", "UNCONFIGURED", "CONFIGURING", "IDLE", 53 "CAPTURING"}; 54 55 private int mCurrentState = STATE_UNCONFIGURED; 56 private int mCurrentError = NO_CAPTURE_ERROR; 57 58 private RequestHolder mCurrentRequest = null; 59 60 private Handler mCurrentHandler = null; 61 private CameraDeviceStateListener mCurrentListener = null; 62 63 /** 64 * Error code used by {@link #setCaptureStart} and {@link #setCaptureResult} to indicate that no 65 * error has occurred. 66 */ 67 public static final int NO_CAPTURE_ERROR = -1; 68 69 /** 70 * CameraDeviceStateListener callbacks to be called after state transitions. 71 */ 72 public interface CameraDeviceStateListener { 73 void onError(int errorCode, Object errorArg, RequestHolder holder); 74 void onConfiguring(); 75 void onIdle(); 76 void onBusy(); 77 void onCaptureStarted(RequestHolder holder, long timestamp); 78 void onCaptureResult(CameraMetadataNative result, RequestHolder holder); 79 void onRequestQueueEmpty(); 80 void onRepeatingRequestError(long lastFrameNumber, int repeatingRequestId); 81 } 82 83 /** 84 * Transition to the {@code ERROR} state. 85 * 86 * <p> 87 * The device cannot exit the {@code ERROR} state. If the device was not already in the 88 * {@code ERROR} state, {@link CameraDeviceStateListener#onError(int, RequestHolder)} will be 89 * called. 90 * </p> 91 * 92 * @param error the error to set. Should be one of the error codes defined in 93 * {@link CameraDeviceImpl.CameraDeviceCallbacks}. 94 */ 95 public synchronized void setError(int error) { 96 mCurrentError = error; 97 doStateTransition(STATE_ERROR); 98 } 99 100 /** 101 * Transition to the {@code CONFIGURING} state, or {@code ERROR} if in an invalid state. 102 * 103 * <p> 104 * If the device was not already in the {@code CONFIGURING} state, 105 * {@link CameraDeviceStateListener#onConfiguring()} will be called. 106 * </p> 107 * 108 * @return {@code false} if an error has occurred. 109 */ 110 public synchronized boolean setConfiguring() { 111 doStateTransition(STATE_CONFIGURING); 112 return mCurrentError == NO_CAPTURE_ERROR; 113 } 114 115 /** 116 * Transition to the {@code IDLE} state, or {@code ERROR} if in an invalid state. 117 * 118 * <p> 119 * If the device was not already in the {@code IDLE} state, 120 * {@link CameraDeviceStateListener#onIdle()} will be called. 121 * </p> 122 * 123 * @return {@code false} if an error has occurred. 124 */ 125 public synchronized boolean setIdle() { 126 doStateTransition(STATE_IDLE); 127 return mCurrentError == NO_CAPTURE_ERROR; 128 } 129 130 /** 131 * Transition to the {@code CAPTURING} state, or {@code ERROR} if in an invalid state. 132 * 133 * <p> 134 * If the device was not already in the {@code CAPTURING} state, 135 * {@link CameraDeviceStateListener#onCaptureStarted(RequestHolder)} will be called. 136 * </p> 137 * 138 * @param request A {@link RequestHolder} containing the request for the current capture. 139 * @param timestamp The timestamp of the capture start in nanoseconds. 140 * @param captureError Report a recoverable error for a single request using a valid 141 * error code for {@code ICameraDeviceCallbacks}, or 142 * {@link #NO_CAPTURE_ERROR} 143 * @return {@code false} if an error has occurred. 144 */ 145 public synchronized boolean setCaptureStart(final RequestHolder request, long timestamp, 146 int captureError) { 147 mCurrentRequest = request; 148 doStateTransition(STATE_CAPTURING, timestamp, captureError); 149 return mCurrentError == NO_CAPTURE_ERROR; 150 } 151 152 /** 153 * Set the result for a capture. 154 * 155 * <p> 156 * If the device was in the {@code CAPTURING} state, 157 * {@link CameraDeviceStateListener#onCaptureResult(CameraMetadataNative, RequestHolder)} will 158 * be called with the given result, otherwise this will result in the device transitioning to 159 * the {@code ERROR} state, 160 * </p> 161 * 162 * @param request The {@link RequestHolder} request that created this result. 163 * @param result The {@link CameraMetadataNative} result to set. 164 * @param captureError Report a recoverable error for a single buffer or result using a valid 165 * error code for {@code ICameraDeviceCallbacks}, or 166 * {@link #NO_CAPTURE_ERROR}. 167 * @param captureErrorArg An argument for some error captureError codes. 168 * @return {@code false} if an error has occurred. 169 */ 170 public synchronized boolean setCaptureResult(final RequestHolder request, 171 final CameraMetadataNative result, 172 final int captureError, final Object captureErrorArg) { 173 if (mCurrentState != STATE_CAPTURING) { 174 Log.e(TAG, "Cannot receive result while in state: " + mCurrentState); 175 mCurrentError = CameraDeviceImpl.CameraDeviceCallbacks.ERROR_CAMERA_DEVICE; 176 doStateTransition(STATE_ERROR); 177 return mCurrentError == NO_CAPTURE_ERROR; 178 } 179 180 if (mCurrentHandler != null && mCurrentListener != null) { 181 if (captureError != NO_CAPTURE_ERROR) { 182 mCurrentHandler.post(new Runnable() { 183 @Override 184 public void run() { 185 mCurrentListener.onError(captureError, captureErrorArg, request); 186 } 187 }); 188 } else { 189 mCurrentHandler.post(new Runnable() { 190 @Override 191 public void run() { 192 mCurrentListener.onCaptureResult(result, request); 193 } 194 }); 195 } 196 } 197 return mCurrentError == NO_CAPTURE_ERROR; 198 } 199 200 public synchronized boolean setCaptureResult(final RequestHolder request, 201 final CameraMetadataNative result) { 202 return setCaptureResult(request, result, NO_CAPTURE_ERROR, /*errorArg*/null); 203 } 204 205 /** 206 * Set repeating request error. 207 * 208 * <p>Repeating request has been stopped due to an error such as abandoned output surfaces.</p> 209 * 210 * @param lastFrameNumber Frame number of the last repeating request before it is stopped. 211 * @param repeatingRequestId The ID of the repeating request being stopped 212 */ 213 public synchronized void setRepeatingRequestError(final long lastFrameNumber, 214 final int repeatingRequestId) { 215 mCurrentHandler.post(new Runnable() { 216 @Override 217 public void run() { 218 mCurrentListener.onRepeatingRequestError(lastFrameNumber, repeatingRequestId); 219 } 220 }); 221 } 222 223 /** 224 * Indicate that request queue (non-repeating) becomes empty. 225 * 226 * <p> Send notification that all non-repeating requests have been sent to camera device. </p> 227 */ 228 public synchronized void setRequestQueueEmpty() { 229 mCurrentHandler.post(new Runnable() { 230 @Override 231 public void run() { 232 mCurrentListener.onRequestQueueEmpty(); 233 } 234 }); 235 } 236 237 /** 238 * Set the listener for state transition callbacks. 239 * 240 * @param handler handler on which to call the callbacks. 241 * @param listener the {@link CameraDeviceStateListener} callbacks to call. 242 */ 243 public synchronized void setCameraDeviceCallbacks(Handler handler, 244 CameraDeviceStateListener listener) { 245 mCurrentHandler = handler; 246 mCurrentListener = listener; 247 } 248 249 private void doStateTransition(int newState) { 250 doStateTransition(newState, /*timestamp*/0, NO_CAPTURE_ERROR); 251 } 252 253 private void doStateTransition(int newState, final long timestamp, final int error) { 254 if (newState != mCurrentState) { 255 String stateName = "UNKNOWN"; 256 if (newState >= 0 && newState < sStateNames.length) { 257 stateName = sStateNames[newState]; 258 } 259 Log.i(TAG, "Legacy camera service transitioning to state " + stateName); 260 } 261 262 // If we transitioned into a non-IDLE/non-ERROR state then mark the device as busy 263 if(newState != STATE_ERROR && newState != STATE_IDLE) { 264 if (mCurrentState != newState && mCurrentHandler != null && 265 mCurrentListener != null) { 266 mCurrentHandler.post(new Runnable() { 267 @Override 268 public void run() { 269 mCurrentListener.onBusy(); 270 } 271 }); 272 } 273 } 274 275 switch(newState) { 276 case STATE_ERROR: 277 if (mCurrentState != STATE_ERROR && mCurrentHandler != null && 278 mCurrentListener != null) { 279 mCurrentHandler.post(new Runnable() { 280 @Override 281 public void run() { 282 mCurrentListener.onError(mCurrentError, /*errorArg*/null, mCurrentRequest); 283 } 284 }); 285 } 286 mCurrentState = STATE_ERROR; 287 break; 288 case STATE_CONFIGURING: 289 if (mCurrentState != STATE_UNCONFIGURED && mCurrentState != STATE_IDLE) { 290 Log.e(TAG, "Cannot call configure while in state: " + mCurrentState); 291 mCurrentError = CameraDeviceImpl.CameraDeviceCallbacks.ERROR_CAMERA_DEVICE; 292 doStateTransition(STATE_ERROR); 293 break; 294 } 295 if (mCurrentState != STATE_CONFIGURING && mCurrentHandler != null && 296 mCurrentListener != null) { 297 mCurrentHandler.post(new Runnable() { 298 @Override 299 public void run() { 300 mCurrentListener.onConfiguring(); 301 } 302 }); 303 } 304 mCurrentState = STATE_CONFIGURING; 305 break; 306 case STATE_IDLE: 307 if (mCurrentState == STATE_IDLE) { 308 break; 309 } 310 311 if (mCurrentState != STATE_CONFIGURING && mCurrentState != STATE_CAPTURING) { 312 Log.e(TAG, "Cannot call idle while in state: " + mCurrentState); 313 mCurrentError = CameraDeviceImpl.CameraDeviceCallbacks.ERROR_CAMERA_DEVICE; 314 doStateTransition(STATE_ERROR); 315 break; 316 } 317 318 if (mCurrentState != STATE_IDLE && mCurrentHandler != null && 319 mCurrentListener != null) { 320 mCurrentHandler.post(new Runnable() { 321 @Override 322 public void run() { 323 mCurrentListener.onIdle(); 324 } 325 }); 326 } 327 mCurrentState = STATE_IDLE; 328 break; 329 case STATE_CAPTURING: 330 if (mCurrentState != STATE_IDLE && mCurrentState != STATE_CAPTURING) { 331 Log.e(TAG, "Cannot call capture while in state: " + mCurrentState); 332 mCurrentError = CameraDeviceImpl.CameraDeviceCallbacks.ERROR_CAMERA_DEVICE; 333 doStateTransition(STATE_ERROR); 334 break; 335 } 336 337 if (mCurrentHandler != null && mCurrentListener != null) { 338 if (error != NO_CAPTURE_ERROR) { 339 mCurrentHandler.post(new Runnable() { 340 @Override 341 public void run() { 342 mCurrentListener.onError(error, /*errorArg*/null, mCurrentRequest); 343 } 344 }); 345 } else { 346 mCurrentHandler.post(new Runnable() { 347 @Override 348 public void run() { 349 mCurrentListener.onCaptureStarted(mCurrentRequest, timestamp); 350 } 351 }); 352 } 353 } 354 mCurrentState = STATE_CAPTURING; 355 break; 356 default: 357 throw new IllegalStateException("Transition to unknown state: " + newState); 358 } 359 } 360 361 362 } 363
