content: /*
   * Copyright (C) 2012 The Android Open Source Project
   *
   * 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.android.gallery3d.exif;
  
  import android.util.Log;
  
  import java.io.IOException;
  import java.io.InputStream;
  
  /**
   * This class reads the EXIF header of a JPEG file and stores it in
   * {@link ExifData}.
   */
  class ExifReader {
      private static final String TAG = "ExifReader";
  
      private final ExifInterface mInterface;
  
      ExifReader(ExifInterface iRef) {
          mInterface = iRef;
      }
  
      /**
       * Parses the inputStream and and returns the EXIF data in an
       * {@link ExifData}.
       *
       * @throws ExifInvalidFormatException
       * @throws IOException
       */
      protected ExifData read(InputStream inputStream) throws ExifInvalidFormatException,
              IOException {
          ExifParser parser = ExifParser.parse(inputStream, mInterface);
          ExifData exifData = new ExifData(parser.getByteOrder());
          ExifTag tag = null;
  
          int event = parser.next();
          while (event != ExifParser.EVENT_END) {
              switch (event) {
                  case ExifParser.EVENT_START_OF_IFD:
                      exifData.addIfdData(new IfdData(parser.getCurrentIfd()));
                      break;
                  case ExifParser.EVENT_NEW_TAG:
                      tag = parser.getTag();
                      if (!tag.hasValue()) {
                          parser.registerForTagValue(tag);
                      } else {
                          exifData.getIfdData(tag.getIfd()).setTag(tag);
                      }
                      break;
                  case ExifParser.EVENT_VALUE_OF_REGISTERED_TAG:
                      tag = parser.getTag();
                      if (tag.getDataType() == ExifTag.TYPE_UNDEFINED) {
                          parser.readFullTagValue(tag);
                      }
                      exifData.getIfdData(tag.getIfd()).setTag(tag);
                      break;
                  case ExifParser.EVENT_COMPRESSED_IMAGE:
                      byte buf[] = new byte[parser.getCompressedImageSize()];
                      if (buf.length == parser.read(buf)) {
                          exifData.setCompressedThumbnail(buf);
                      } else {
                          Log.w(TAG, "Failed to read the compressed thumbnail");
                      }
                      break;
                  case ExifParser.EVENT_UNCOMPRESSED_STRIP:
                      buf = new byte[parser.getStripSize()];
                      if (buf.length == parser.read(buf)) {
                          exifData.setStripBytes(parser.getStripIndex(), buf);
                      } else {
                          Log.w(TAG, "Failed to read the strip bytes");
                      }
                      break;
              }
              event = parser.next();
          }
          return exifData;
      }
  }
  