circle_image.kt

//CircularImageView
//--------------------------------------------------------------------------------

import android.content.Context
import android.graphics.*
import android.graphics.drawable.Drawable
import android.util.AttributeSet
import android.util.TypedValue
import android.view.View

class CircularImageView(context: Context, attrs: AttributeSet) : View(context, attrs) {

    private var drawable: Drawable? = null
    private val paint = Paint().apply {
        isAntiAlias = true
    }
    private val padding: Float

    init {
        // Convert 8dp to pixels
        padding = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 8f, resources.displayMetrics)
    }

    fun setImageDrawable(drawable: Drawable) {
        this.drawable = drawable
        invalidate()
    }

    override fun onDraw(canvas: Canvas) {
        super.onDraw(canvas)

        drawable?.let {
            val bitmap = getBitmapFromDrawable(it)
            val shader = BitmapShader(bitmap, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP)
            val matrix = Matrix()

            // Always use ScaleType.FIT_XY
            val scaleX = (width - 2 * padding) / bitmap.width.toFloat()
            val scaleY = (height - 2 * padding) / bitmap.height.toFloat()

            matrix.setScale(scaleX, scaleY)
            shader.setLocalMatrix(matrix)
            paint.shader = shader

            val radius = (Math.min(width, height) - 2 * padding) / 2f
            canvas.drawCircle(width / 2f, height / 2f, radius, paint)
        }
    }

    private fun getBitmapFromDrawable(drawable: Drawable): Bitmap {
        val bitmap = Bitmap.createBitmap(drawable.intrinsicWidth, drawable.intrinsicHeight, Bitmap.Config.ARGB_8888)
        val canvas = Canvas(bitmap)
        drawable.setBounds(0, 0, canvas.width, canvas.height)
        drawable.draw(canvas)
        return bitmap
    }
}


//--------------------------------------------------------------------------------

//Implamentation


 val circularImageView = findViewById<CircularImageView>(R.id.circularImageView)
        val drawable = getDrawable(R.drawable.ic_launcher_background)
        drawable?.let {
            circularImageView.setImageDrawable(it)
        }