content: /*
   * Copyright (C) 2008 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.xys.libzxing.zxing.camera;
  
  import android.content.Context;
  import android.graphics.Point;
  import android.hardware.Camera;
  import android.hardware.Camera.Size;
  import android.os.Handler;
  import android.util.Log;
  import android.view.SurfaceHolder;
  
  import com.xys.libzxing.zxing.camera.open.OpenCameraInterface;
  
  import java.io.IOException;
  
  /**
   * This object wraps the Camera service object and expects to be the only one
   * talking to it. The implementation encapsulates the steps needed to take
   * preview-sized images, which are used for both preview and decoding.
   *
   * @author dswitkin@google.com (Daniel Switkin)
   */
  public class CameraManager {
  
      private static final String TAG = CameraManager.class.getSimpleName();
  
      private final Context context;
      private final CameraConfigurationManager configManager;
      /**
       * Preview frames are delivered here, which we pass on to the registered
       * handler. Make sure to clear the handler so it will only receive one
       * message.
       */
      private final PreviewCallback previewCallback;
      private Camera camera;
      private AutoFocusManager autoFocusManager;
      private boolean initialized;
      private boolean previewing;
      private int requestedCameraId = -1;
  
      public CameraManager(Context context) {
          this.context = context;
          this.configManager = new CameraConfigurationManager(context);
          previewCallback = new PreviewCallback(configManager);
      }
  
      /**
       * Opens the camera driver and initializes the hardware parameters.
       *
       * @param holder The surface object which the camera will draw preview frames
       *               into.
       * @throws IOException Indicates the camera driver failed to open.
       */
      public synchronized void openDriver(SurfaceHolder holder) throws IOException {
          Camera theCamera = camera;
          if (theCamera == null) {
  
              if (requestedCameraId >= 0) {
                  theCamera = OpenCameraInterface.open(requestedCameraId);
              } else {
                  theCamera = OpenCameraInterface.open();
              }
  
              if (theCamera == null) {
                  throw new IOException();
              }
              camera = theCamera;
          }
          theCamera.setPreviewDisplay(holder);
  
          if (!initialized) {
              initialized = true;
              configManager.initFromCameraParameters(theCamera);
          }
  
          Camera.Parameters parameters = theCamera.getParameters();
          String parametersFlattened = parameters == null ? null : parameters.flatten(); // Save
          // these,
          // temporarily
          try {
              configManager.setDesiredCameraParameters(theCamera, false);
          } catch (RuntimeException re) {
              // Driver failed
              Log.w(TAG, "Camera rejected parameters. Setting only minimal safe-mode parameters");
              Log.i(TAG, "Resetting to saved camera params: " + parametersFlattened);
              // Reset:
              if (parametersFlattened != null) {
                  parameters = theCamera.getParameters();
                  parameters.unflatten(parametersFlattened);
                  try {
                      theCamera.setParameters(parameters);
                      configManager.setDesiredCameraParameters(theCamera, true);
                  } catch (RuntimeException re2) {
                      // Well, darn. Give up
                      Log.w(TAG, "Camera rejected even safe-mode parameters! No configuration");
                  }
              }
          }
  
      }
  
      public synchronized boolean isOpen() {
          return camera != null;
      }
  
      /**
       * Closes the camera driver if still in use.
       */
      public synchronized void closeDriver() {
          if (camera != null) {
              camera.release();
              camera = null;
              // Make sure to clear these each time we close the camera, so that
              // any scanning rect
              // requested by intent is forgotten.
          }
      }
  
      /**
       * Asks the camera hardware to begin drawing preview frames to the screen.
       */
      public synchronized void startPreview() {
          Camera theCamera = camera;
          if (theCamera != null && !previewing) {
              theCamera.startPreview();
              previewing = true;
              autoFocusManager = new AutoFocusManager(context, camera);
          }
      }
  
      /**
       * Tells the camera to stop drawing preview frames.
       */
      public synchronized void stopPreview() {
          if (autoFocusManager != null) {
              autoFocusManager.stop();
              autoFocusManager = null;
          }
          if (camera != null && previewing) {
              camera.stopPreview();
              previewCallback.setHandler(null, 0);
              previewing = false;
          }
      }
  
      /**
       * A single preview frame will be returned to the handler supplied. The data
       * will arrive as byte[] in the message.obj field, with width and height
       * encoded as message.arg1 and message.arg2, respectively.
       *
       * @param handler The handler to send the message to.
       * @param message The what field of the message to be sent.
       */
      public synchronized void requestPreviewFrame(Handler handler, int message) {
          Camera theCamera = camera;
          if (theCamera != null && previewing) {
              previewCallback.setHandler(handler, message);
              theCamera.setOneShotPreviewCallback(previewCallback);
          }
      }
  
      /**
       * Allows third party apps to specify the camera ID, rather than determine
       * it automatically based on available cameras and their orientation.
       *
       * @param cameraId camera ID of the camera to use. A negative value means
       *                 "no preference".
       */
      public synchronized void setManualCameraId(int cameraId) {
          requestedCameraId = cameraId;
      }
  
      /**
       * 获取相机分辨率
       *
       * @return
       */
      public Point getCameraResolution() {
          return configManager.getCameraResolution();
      }
  
      public Size getPreviewSize() {
          if (null != camera) {
              return camera.getParameters().getPreviewSize();
          }
          return null;
      }
  }
  