content: /*
   * Copyright (C) 2012 ZXing authors
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package org.fly.scan.camera.open;
  import android.hardware.Camera;
  import android.util.Log;
  
  /**
   * Abstraction over the {@link Camera} API that helps open them and return their metadata.
   */
  @SuppressWarnings("deprecation") // camera APIs
  public final class OpenCameraInterface {
  
      private static final String TAG = OpenCameraInterface.class.getName();
  
      /** For {@link #open(int)}, means no preference for which camera to open. */
      public static final int NO_REQUESTED_CAMERA = -1;
  
      private OpenCameraInterface() {
      }
  
      /**
       * Opens the requested camera with {@link Camera#open(int)}, if one exists.
       *
       * @param cameraId camera ID of the camera to use. A negative value
       *  or {@link #NO_REQUESTED_CAMERA} means "no preference", in which case a rear-facing
       *  camera is returned if possible or else any camera
       * @return handle to {@link OpenCamera} that was opened
       */
      public static OpenCamera open(int cameraId) {
  
          int numCameras = Camera.getNumberOfCameras();
          if (numCameras == 0) {
              Log.w(TAG, "No cameras!");
              return null;
          }
          if (cameraId >= numCameras) {
              Log.w(TAG, "Requested camera does not exist: " + cameraId);
              return null;
          }
  
          if (cameraId <= NO_REQUESTED_CAMERA) {
              cameraId = 0;
              while (cameraId < numCameras) {
                  Camera.CameraInfo cameraInfo = new Camera.CameraInfo();
                  Camera.getCameraInfo(cameraId, cameraInfo);
                  if (CameraFacing.values()[cameraInfo.facing] == CameraFacing.BACK) {
                      break;
                  }
                  cameraId++;
              }
              if (cameraId == numCameras) {
                  Log.i(TAG, "No camera facing " + CameraFacing.BACK + "; returning camera #0");
                  cameraId = 0;
              }
          }
  
          Log.i(TAG, "Opening camera #" + cameraId);
          Camera.CameraInfo cameraInfo = new Camera.CameraInfo();
          Camera.getCameraInfo(cameraId, cameraInfo);
          Camera camera = Camera.open(cameraId);
          if (camera == null) {
              return null;
          }
          return new OpenCamera(cameraId,
                  camera,
                  CameraFacing.values()[cameraInfo.facing],
                  cameraInfo.orientation);
      }
  }
  