src/com/owncloud/android/utils/BitmapUtils.java

   1 /**
   2  *   ownCloud Android client application
   3  *
   4  *   @author David A. Velasco
   5  *   Copyright (C) 2015 ownCloud Inc.
   6  *
   7  *   This program is free software: you can redistribute it and/or modify
   8  *   it under the terms of the GNU General Public License version 2,
   9  *   as published by the Free Software Foundation.
  10  *
  11  *   This program is distributed in the hope that it will be useful,
  12  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *   GNU General Public License for more details.
  15  *
  16  *   You should have received a copy of the GNU General Public License
  17  *   along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18  *
  19  */
  20 package com.owncloud.android.utils;
  21
  22 import com.owncloud.android.lib.common.utils.Log_OC;
  23
  24 import android.graphics.Bitmap;
  25 import android.graphics.BitmapFactory;
  26 import android.graphics.Matrix;
  27 import android.graphics.BitmapFactory.Options;
  28 import android.media.ExifInterface;
  29 import android.net.Uri;
  30 import android.webkit.MimeTypeMap;
  31
  32 import java.io.File;
  33
  34 /**
  35  * Utility class with methods for decoding Bitmaps.
  36  */
  37 public class BitmapUtils {
  38
  39
  40     /**
  41      * Decodes a bitmap from a file containing it minimizing the memory use, known that the bitmap
  42      * will be drawn in a surface of reqWidth x reqHeight
  43      *
  44      * @param srcPath       Absolute path to the file containing the image.
  45      * @param reqWidth      Width of the surface where the Bitmap will be drawn on, in pixels.
  46      * @param reqHeight     Height of the surface where the Bitmap will be drawn on, in pixels.
  47      * @return
  48      */
  49     public static Bitmap decodeSampledBitmapFromFile(String srcPath, int reqWidth, int reqHeight) {
  50
  51         // set desired options that will affect the size of the bitmap
  52         final Options options = new Options();
  53         options.inScaled = true;
  54         options.inPurgeable = true;
  55         if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.GINGERBREAD_MR1) {
  56             options.inPreferQualityOverSpeed = false;
  57         }
  58         if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.HONEYCOMB) {
  59             options.inMutable = false;
  60         }
  61
  62         // make a false load of the bitmap to get its dimensions
  63         options.inJustDecodeBounds = true;
  64
  65         BitmapFactory.decodeFile(srcPath, options);
  66
  67         // calculate factor to subsample the bitmap
  68         options.inSampleSize = calculateSampleFactor(options, reqWidth, reqHeight);
  69
  70         // decode bitmap with inSampleSize set
  71         options.inJustDecodeBounds = false;
  72         return BitmapFactory.decodeFile(srcPath, options);
  73
  74     }
  75
  76
  77     /**
  78      * Calculates a proper value for options.inSampleSize in order to decode a Bitmap minimizing
  79      * the memory overload and covering a target surface of reqWidth x reqHeight if the original
  80      * image is big enough.
  81      *
  82      * @param options       Bitmap decoding options; options.outHeight and options.inHeight should
  83      *                      be set.
  84      * @param reqWidth      Width of the surface where the Bitmap will be drawn on, in pixels.
  85      * @param reqHeight     Height of the surface where the Bitmap will be drawn on, in pixels.
  86      * @return              The largest inSampleSize value that is a power of 2 and keeps both
  87      *                      height and width larger than reqWidth and reqHeight.
  88      */
  89     private static int calculateSampleFactor(Options options, int reqWidth, int reqHeight) {
  90
  91         final int height = options.outHeight;
  92         final int width = options.outWidth;
  93         int inSampleSize = 1;
  94
  95         if (height > reqHeight || width > reqWidth) {
  96             final int halfHeight = height / 2;
  97             final int halfWidth = width / 2;
  98
  99             while ((halfHeight / inSampleSize) > reqHeight
 100                     && (halfWidth / inSampleSize) > reqWidth) {
 101                 inSampleSize *= 2;
 102             }
 103         }
 104
 105         return inSampleSize;
 106     }
 107
 108     /**
 109      * Rotate bitmap according to EXIF orientation.
 110      * Cf. http://www.daveperrett.com/articles/2012/07/28/exif-orientation-handling-is-a-ghetto/
 111      * @param bitmap Bitmap to be rotated
 112      * @param storagePath Path to source file of bitmap. Needed for EXIF information.
 113      * @return correctly EXIF-rotated bitmap
 114      */
 115     public static Bitmap rotateImage(Bitmap bitmap, String storagePath){
 116         Bitmap resultBitmap = bitmap;
 117
 118         try
 119         {
 120             ExifInterface exifInterface = new ExifInterface(storagePath);
 121             int orientation = exifInterface.getAttributeInt(ExifInterface.TAG_ORIENTATION, 1);
 122
 123             Matrix matrix = new Matrix();
 124
 125             // 1: nothing to do
 126
 127             // 2
 128             if (orientation == ExifInterface.ORIENTATION_FLIP_HORIZONTAL)
 129             {
 130                 matrix.postScale(-1.0f, 1.0f);
 131             }
 132             // 3
 133             else if (orientation == ExifInterface.ORIENTATION_ROTATE_180)
 134             {
 135                 matrix.postRotate(180);
 136             }
 137             // 4
 138             else if (orientation == ExifInterface.ORIENTATION_FLIP_VERTICAL)
 139             {
 140                 matrix.postScale(1.0f, -1.0f);
 141             }
 142             // 5
 143             else if (orientation == ExifInterface.ORIENTATION_TRANSPOSE)
 144             {
 145                 matrix.postRotate(-90);
 146                 matrix.postScale(1.0f, -1.0f);
 147             }
 148             // 6
 149             else if (orientation == ExifInterface.ORIENTATION_ROTATE_90)
 150             {
 151                 matrix.postRotate(90);
 152             }
 153             // 7
 154             else if (orientation == ExifInterface.ORIENTATION_TRANSVERSE)
 155             {
 156                 matrix.postRotate(90);
 157                 matrix.postScale(1.0f, -1.0f);
 158             }
 159             // 8
 160             else if (orientation == ExifInterface.ORIENTATION_ROTATE_270)
 161             {
 162                 matrix.postRotate(270);
 163             }
 164
 165             // Rotate the bitmap
 166             resultBitmap = Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(), bitmap.getHeight(), matrix, true);
 167             if (resultBitmap != bitmap) {
 168                 bitmap.recycle();
 169             }
 170         }
 171         catch (Exception exception)
 172         {
 173             Log_OC.e("BitmapUtil", "Could not rotate the image: " + storagePath);
 174         }
 175         return resultBitmap;
 176     }
 177
 178     /**
 179      * Checks if file passed is an image
 180      * @param file
 181      * @return true/false
 182      */
 183     public static boolean isImage(File file) {
 184         Uri selectedUri = Uri.fromFile(file);
 185         String fileExtension = MimeTypeMap.getFileExtensionFromUrl(selectedUri.toString().toLowerCase());
 186         String mimeType = MimeTypeMap.getSingleton().getMimeTypeFromExtension(fileExtension);
 187
 188         return (mimeType != null && mimeType.startsWith("image/"));
 189     }
 190
 191 }