gistfile1.java

@TargetApi(Build.VERSION_CODES.KITKAT) 
static class DocumentExifTransformation implements Transformation {
    private static final String[] CONTENT_ORIENTATION = new String[] {
        MediaStore.Images.ImageColumns.ORIENTATION
    };

    final Context context;
    final Uri uri;

    DocumentExifTransformation(Context context, Uri uri) {
      this.context = context;
      this.uri = uri;
    }

    @Override public Bitmap transform(Bitmap source) {
      if (Build.VERSION.SDK_INT < Build.VERSION_CODES.KITKAT) return source;
      if (!DocumentsContract.isDocumentUri(context, uri)) return source;

      int exifRotation = getExifOrientation(context, uri);
      if (exifRotation != 0) {
        Matrix matrix = new Matrix();
        matrix.preRotate(exifRotation);

        Bitmap rotated =
            Bitmap.createBitmap(source, 0, 0, source.getWidth(), source.getHeight(), matrix, true);
        if (rotated != source) {
          source.recycle();
        }
        return rotated;
      }

      return source;
    }

    @Override public String key() {
      if (Build.VERSION.SDK_INT < Build.VERSION_CODES.KITKAT) return "documentTransform()";
      return "documentExifTransform(" + DocumentsContract.getDocumentId(uri) + ")";
    }

    static int getExifOrientation(Context context, Uri uri) {
      ContentResolver contentResolver = context.getContentResolver();
      Cursor cursor = null;
      try {
        String id = DocumentsContract.getDocumentId(uri);
        id = id.split(":")[1];
        cursor = contentResolver.query(MediaStore.Images.Media.EXTERNAL_CONTENT_URI,
            CONTENT_ORIENTATION, MediaStore.Images.Media._ID + " = ?", new String[] { id }, null);
        if (cursor == null || !cursor.moveToFirst()) {
          return 0;
        }
        return cursor.getInt(0);
      } catch (RuntimeException ignored) {
        // If the orientation column doesn't exist, assume no rotation.
        return 0;
      } finally {
        if (cursor != null) {
          cursor.close();
        }
      }
    }
  }

Thanks for writing this class up! It's helping me a great deal so far.

Something to look out for, I had to update the key method to guard against non-document IDs:

@Override
public String key() {
        if ((Build.VERSION.SDK_INT < Build.VERSION_CODES.KITKAT) || 
                !DocumentsContract.isDocumentUri(context, uri)) return "documentTransform()";
        return "documentExifTransform(" + DocumentsContract.getDocumentId(uri) + ")";
    }