loading button code in progress

LoadingButton.kt

package com.udacity

import android.animation.ValueAnimator
import android.content.Context
import android.graphics.Canvas
import android.graphics.Paint
import android.graphics.RectF
import android.util.AttributeSet
import android.view.View
import kotlin.properties.Delegates

class LoadingButton @JvmOverloads constructor(
    context: Context, attrs: AttributeSet? = null, defStyleAttr: Int = 0
) : View(context, attrs, defStyleAttr) {

    private var buttonBackgroundColor = 0
    private var buttonTextColor = 0
    private var widthSize = resources.getDimension(R.dimen.buttonWidth)
    private var heightSize = resources.getDimension(R.dimen.buttonHeight)
    private val valueAnimator = ValueAnimator()
    private val rect = RectF(0f, 0f, widthSize, heightSize)

    private var buttonState: ButtonState by Delegates.observable(ButtonState.Completed)
    { p, old, new ->

    }

    private val buttonBackgroundPaint = Paint(Paint.ANTI_ALIAS_FLAG).apply {
        style = Paint.Style.FILL


    }

    private val buttonTextPaint = Paint(Paint.ANTI_ALIAS_FLAG).apply {
        textSize = resources.getDimension(R.dimen.default_text_size)
        textAlign = Paint.Align.CENTER


    }


    init {
        buttonBackgroundColor = resources.getColor(R.color.colorPrimary, null)
        buttonTextColor = resources.getColor(R.color.white, null)
        isClickable = true
    }


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

        canvas?.apply {
            buttonBackgroundPaint.color = buttonBackgroundColor
            buttonTextPaint.color = buttonTextColor
            drawRect(rect, buttonBackgroundPaint)
            drawText(
                resources.getString(
                    R.string.download_button_label
                ),
                widthSize / 2, heightSize / 2, buttonTextPaint
            )
        }


    }


    override fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int) {
        val minw: Int = paddingLeft + paddingRight + suggestedMinimumWidth
        val w: Int = resolveSizeAndState(minw, widthMeasureSpec, 1)
        val h: Int = resolveSizeAndState(
            MeasureSpec.getSize(w),
            heightMeasureSpec,
            0
        )
        this.widthSize = w.toFloat()
        heightSize = h.toFloat()
        setMeasuredDimension(w, h)
    }

}