Adding border (color and width) to Coil.RoundedCornersTransformation

BorderedRoundedCornersTransformation.kt

import android.graphics.Bitmap
import android.graphics.Color
import android.graphics.Paint
import android.graphics.PorterDuff
import android.graphics.PorterDuffXfermode
import androidx.annotation.ColorInt
import androidx.core.graphics.applyCanvas
import androidx.core.graphics.createBitmap
import coil.size.Size
import coil.transform.Transformation

class BorderedCircleCropTransformation(
    private val borderWidthPx: Float = 0f,
    @ColorInt private val borderColor: Int = Color.TRANSPARENT,
) : Transformation {

    override val cacheKey: String = javaClass.name

    override suspend fun transform(input: Bitmap, size: Size): Bitmap {
        val paint = Paint(Paint.ANTI_ALIAS_FLAG or Paint.FILTER_BITMAP_FLAG)

        val minSize = minOf(input.width, input.height)
        val radius = minSize / 2f

        val output = createBitmap(minSize, minSize, input.config)
        output.applyCanvas {
            drawCircle(radius, radius, radius, paint)
            paint.xfermode = PorterDuffXfermode(PorterDuff.Mode.SRC_IN)
            drawBitmap(input, radius - input.width / 2f, radius - input.height / 2f, paint)

            if (borderWidthPx > 0f) {
                //border color
                drawCircle(radius,
                    radius,
                    radius,
                    paint.apply {
                        style = Paint.Style.STROKE
                        paint.strokeWidth = borderWidthPx
                        paint.color = borderColor
                    })
            }
        }
        return output
    }

    override fun equals(other: Any?): Boolean {
        if (this === other) return true
        if (javaClass != other?.javaClass) return false

        other as BorderedCircleCropTransformation

        if (borderWidthPx != other.borderWidthPx) return false
        if (borderColor != other.borderColor) return false
        if (cacheKey != other.cacheKey) return false

        return true
    }

    override fun hashCode(): Int {
        var result = borderWidthPx.hashCode()
        result = 31 * result + borderColor
        result = 31 * result + cacheKey.hashCode()
        return result
    }
}