Rotate an image/bitmap

RotateImage.kt

import android.graphics.Bitmap
import android.graphics.Matrix
import android.support.media.ExifInterface
import java.io.File

class ImageUtils {

    companion object {

        /**
         * Some devices take a photo side ways. Specially Samsung devices. This makes sure that the
         * photo is rotated accordingly to make it straight again.
         *
         * @param bitmap the bitmap to be rotated
         * @param file a file containing the bitmap
         */
        fun rotateBitmapIfNeeded(bitmap: Bitmap, file: File): Bitmap {
            val matrix = Matrix()
            val exifInterface = ExifInterface(file.path)
            val orientationToRotateTo = exifInterface
                    .getAttributeInt(ExifInterface.TAG_ORIENTATION, ExifInterface.ORIENTATION_NORMAL)

            val degreeToRotateTo = when (orientationToRotateTo) {
                ExifInterface.ORIENTATION_ROTATE_90 -> 90f
                ExifInterface.ORIENTATION_ROTATE_180 -> 180f
                ExifInterface.ORIENTATION_ROTATE_270 -> 270f
                else -> 0f
            }

            matrix.postRotate(degreeToRotateTo)
            
            return Bitmap.createBitmap(bitmap, 0, 0, bitmap.width, bitmap.height, matrix, true)
        }
    }
}