Button with Shadow. What else?

ButtonWithShadow.kt

import android.content.Context
import android.graphics.BlurMaskFilter
import android.graphics.Canvas
import android.graphics.Color
import android.graphics.Paint
import android.util.AttributeSet
import android.widget.TextView

class ButtonWithShadow : TextView {

    constructor(context: Context?) : super(context)
    constructor(context: Context?, attrs: AttributeSet?) : super(context, attrs)

    private val mShadowBlur = 56f
    private val mShadowOffsetW = mShadowBlur / 56f * 64f
    private val mShadowOffsetH = mShadowBlur / 56f * 48f
    private val mBackgroundRatio = 42 / mShadowBlur

    private var mShadowOffsetY = 24f
    private var mRadius = 24f

    private val shadowPaint by lazy {
        Paint(0).apply {
            color = Color.parseColor("#00B761")
            style = Paint.Style.FILL
            maskFilter = BlurMaskFilter(mShadowBlur, BlurMaskFilter.Blur.NORMAL)
        }
    }

    private val rectPaint by lazy {
        Paint(Paint.ANTI_ALIAS_FLAG).apply {
            color = Color.parseColor("#00B761")
            style = Paint.Style.FILL
        }
    }

    init {
        setLayerType(LAYER_TYPE_SOFTWARE, null)
    }

    override fun onDraw(canvas: Canvas) {
        canvas.drawRoundRect(
            mShadowOffsetW,
            mShadowOffsetH + mShadowOffsetY,
            width - mShadowOffsetW,
            height - mShadowOffsetH,
            mRadius,
            mRadius,
            shadowPaint
        )
        canvas.drawRoundRect(
            mShadowOffsetW * mBackgroundRatio,
            mShadowOffsetH * mBackgroundRatio,
            width - mShadowOffsetW * mBackgroundRatio,
            height - mShadowOffsetH * mBackgroundRatio,
            mRadius,
            mRadius,
            rectPaint
        )
        super.onDraw(canvas)
    }
}