Create animated GIFs using square/gifencoder

GifBuilder.kt

import android.graphics.Bitmap
import com.squareup.gifencoder.*
import java.io.File
import java.io.OutputStream
import java.util.concurrent.TimeUnit

class GifBuilder(file: File,
                 width: Int,
                 height: Int,
                 private val delay: Long = 250,
                 private val unit: TimeUnit = TimeUnit.MILLISECONDS) {
    
    private val encoder: GifEncoder
    private val os: OutputStream
    
    init {
        os = file.outputStream()
        encoder = GifEncoder(os, width, height, 0)
    }

    fun add(frame: Bitmap) {
        val options = ImageOptions()
        options.setDelay(delay, unit)
        options.setColorQuantizer(KMeansQuantizer.INSTANCE)
        options.setDitherer(FloydSteinbergDitherer.INSTANCE)
        encoder.addImage(pixels(frame), options)
    }

    fun close() {
        encoder.finishEncoding()
        os.close()
    }

    companion object {

        @JvmStatic
        private fun pixels(bitmap: Bitmap): Array<IntArray> {
            val width = bitmap.width
            val height = bitmap.height
            val pixels = IntArray(width * height)
            bitmap.getPixels(pixels, 0, width, 0, 0, width, height)
            val result = Array(width) { IntArray(height) }
            var i = 0
            var x = 0
            while (x < width) {
                var y = 0
                while (y < height) {
                    result[x][y] = pixels[i]
                    i++
                    y++
                }

                x++
            }

            return result
        }
    }
}