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      1 /*
      2  * Copyright (C) 2016 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package com.android.dialer.callcomposer.camera.exif;
     18 
     19 /**
     20  * This class stores the EXIF header in IFDs according to the JPEG specification. It is the result
     21  * produced by {@link ExifReader}.
     22  *
     23  * @see ExifReader
     24  * @see IfdData
     25  */
     26 public class ExifData {
     27 
     28   private final IfdData[] mIfdDatas = new IfdData[IfdId.TYPE_IFD_COUNT];
     29 
     30   /**
     31    * Adds IFD data. If IFD data of the same type already exists, it will be replaced by the new
     32    * data.
     33    */
     34   void addIfdData(IfdData data) {
     35     mIfdDatas[data.getId()] = data;
     36   }
     37 
     38   /** Returns the {@link IfdData} object corresponding to a given IFD if it exists or null. */
     39   IfdData getIfdData(int ifdId) {
     40     if (ExifTag.isValidIfd(ifdId)) {
     41       return mIfdDatas[ifdId];
     42     }
     43     return null;
     44   }
     45 
     46   /**
     47    * Returns the tag with a given TID in the given IFD if the tag exists. Otherwise returns null.
     48    */
     49   protected ExifTag getTag(short tag, int ifd) {
     50     IfdData ifdData = mIfdDatas[ifd];
     51     return (ifdData == null) ? null : ifdData.getTag(tag);
     52   }
     53 
     54   /**
     55    * Adds the given ExifTag to its default IFD and returns an existing ExifTag with the same TID or
     56    * null if none exist.
     57    */
     58   ExifTag addTag(ExifTag tag) {
     59     if (tag != null) {
     60       int ifd = tag.getIfd();
     61       return addTag(tag, ifd);
     62     }
     63     return null;
     64   }
     65 
     66   /**
     67    * Adds the given ExifTag to the given IFD and returns an existing ExifTag with the same TID or
     68    * null if none exist.
     69    */
     70   private ExifTag addTag(ExifTag tag, int ifdId) {
     71     if (tag != null && ExifTag.isValidIfd(ifdId)) {
     72       IfdData ifdData = getOrCreateIfdData(ifdId);
     73       return ifdData.setTag(tag);
     74     }
     75     return null;
     76   }
     77 
     78   /**
     79    * Returns the {@link IfdData} object corresponding to a given IFD or generates one if none exist.
     80    */
     81   private IfdData getOrCreateIfdData(int ifdId) {
     82     IfdData ifdData = mIfdDatas[ifdId];
     83     if (ifdData == null) {
     84       ifdData = new IfdData(ifdId);
     85       mIfdDatas[ifdId] = ifdData;
     86     }
     87     return ifdData;
     88   }
     89 }
     90