talk-android/app/src/main/java/com/nextcloud/talk/utils/BitmapShrinker.kt
Marcel Hibbe e03f048126
fix displaying of large images
Signed-off-by: Marcel Hibbe <dev@mhibbe.de>
2021-06-09 13:19:49 +02:00

113 lines
3.8 KiB
Kotlin

/*
* Nextcloud Talk application
*
* @author Marcel Hibbe
* Copyright (C) 2021 Marcel Hibbe <dev@mhibbe.de>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package com.nextcloud.talk.utils
import android.graphics.Bitmap
import android.graphics.BitmapFactory
import android.graphics.Matrix
import android.util.Log
import androidx.exifinterface.media.ExifInterface
import java.io.IOException
object BitmapShrinker {
private val TAG = "BitmapShrinker"
private const val DEGREES_90 = 90f
private const val DEGREES_180 = 180f
private const val DEGREES_270 = 270f
fun shrinkBitmap(
path: String,
reqWidth: Int,
reqHeight: Int
): Bitmap {
val bitmap = decodeBitmap(path, reqWidth, reqHeight)
return rotateBitmap(path, bitmap)
}
// solution inspired by https://developer.android.com/topic/performance/graphics/load-bitmap
private fun decodeBitmap(
path: String,
requestedWidth: Int,
requestedHeight: Int
): Bitmap {
return BitmapFactory.Options().run {
inJustDecodeBounds = true
BitmapFactory.decodeFile(path, this)
inSampleSize = getInSampleSize(this, requestedWidth, requestedHeight)
inJustDecodeBounds = false
BitmapFactory.decodeFile(path, this)
}
}
// solution inspired by https://developer.android.com/topic/performance/graphics/load-bitmap
private fun getInSampleSize(
options: BitmapFactory.Options,
requestedWidth: Int,
requestedHeight: Int
): Int {
val (height: Int, width: Int) = options.run { outHeight to outWidth }
var inSampleSize = 1
if (height > requestedHeight || width > requestedWidth) {
val halfHeight: Int = height / 2
val halfWidth: Int = width / 2
// "||" was used instead of "&&". Otherwise it would still crash for wide panorama photos.
while (halfHeight / inSampleSize >= requestedHeight || halfWidth / inSampleSize >= requestedWidth) {
inSampleSize *= 2
}
}
return inSampleSize
}
// solution inspired by https://stackoverflow.com/a/15341203
private fun rotateBitmap(path: String, bitmap: Bitmap): Bitmap {
try {
val exif = ExifInterface(path)
val orientation = exif.getAttributeInt(ExifInterface.TAG_ORIENTATION, 1)
val matrix = Matrix()
when (orientation) {
ExifInterface.ORIENTATION_ROTATE_90 -> {
matrix.postRotate(DEGREES_90)
}
ExifInterface.ORIENTATION_ROTATE_180 -> {
matrix.postRotate(DEGREES_180)
}
ExifInterface.ORIENTATION_ROTATE_270 -> {
matrix.postRotate(DEGREES_270)
}
}
val rotatedBitmap = Bitmap.createBitmap(
bitmap,
0,
0,
bitmap.getWidth(),
bitmap.getHeight(),
matrix,
true
)
return rotatedBitmap
} catch (e: IOException) {
Log.e(TAG, "error while rotating image", e)
}
return bitmap
}
}