Android Open Source - zxingfragmentlib Open Camera Interface

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License

The source code is released under:

Apache License

Java Source Code

/*
 * Copyright (C) 2012 ZXing authors//from   w  ww  . jav a 2  s  .co  m
 *
 * 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.client.android.camera.open;

import android.hardware.Camera;
import android.os.Build;
import android.util.Log;

public final class OpenCameraInterface {

  private static final String TAG = OpenCameraInterface.class.getName();

  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 means "no preference"
   * @return handle to {@link Camera} that was opened
   */
  public static Camera open(int cameraId) {

    Camera camera;

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.GINGERBREAD) {
        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;
        }

        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);
            }
        }
    } else {
        camera = Camera.open();
    }
    
    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);
  }

}

Java Source Code List

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