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 com.google.zxing.open;
  
  import android.hardware.Camera;
  import android.util.Log;
  
  public class OpenCameraInterface {
  
  	private static final String TAG = OpenCameraInterface.class.getName();
  
  	/**
  	 * Opens the requested camera with {@link Camera#open(int)}, if one exists.
  	 * 
  	 * @param cameraId
  	 *            camera ID of the camera to use. A negative value means
  	 *            "no preference"
  	 * @return handle to {@link Camera} that was opened
  	 */
  	public static Camera open(int cameraId) {
  
  		int numCameras = Camera.getNumberOfCameras();
  		if (numCameras == 0) {
  			Log.w(TAG, "No cameras!");
  			return null;
  		}
  
  		boolean explicitRequest = cameraId >= 0;
  
  		if (!explicitRequest) {
  			// Select a camera if no explicit camera requested
  			int index = 0;
  			while (index < numCameras) {
  				Camera.CameraInfo cameraInfo = new Camera.CameraInfo();
  				Camera.getCameraInfo(index, cameraInfo);
  				if (cameraInfo.facing == Camera.CameraInfo.CAMERA_FACING_BACK) {
  					break;
  				}
  				index++;
  			}
  
  			cameraId = index;
  		}
  
  		Camera camera;
  		if (cameraId < numCameras) {
  			Log.i(TAG, "Opening camera #" + cameraId);
  			camera = Camera.open(cameraId);
  		} else {
  			if (explicitRequest) {
  				Log.w(TAG, "Requested camera does not exist: " + cameraId);
  				camera = null;
  			} else {
  				Log.i(TAG, "No camera facing back; returning camera #0");
  				camera = Camera.open(0);
  			}
  		}
  
  		return camera;
  	}
  
  	/**
  	 * Opens a rear-facing camera with {@link Camera#open(int)}, if one exists,
  	 * or opens camera 0.
  	 * 
  	 * @return handle to {@link Camera} that was opened
  	 */
  	public static Camera open() {
  		return open(-1);
  	}
  
  }
  