attrs.xml

<resources>
    <declare-styleable name="ProfitabilityIndexView">
        <attr name="pi_circle_radius" format="dimension" />
        <attr name="pi_circle_color" format="color" />
        <attr name="pi_percentage" format="integer" />
        <attr name="pi_circle_spacing" format="dimension" />
        <attr name="pi_number_of_circles" format="integer" />
    </declare-styleable>
</resources>

ProfitabilityIndexView.kt

private const val DEFAULT_NUMBER_OF_CIRCLES = 10

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

    private val rect = RectF()
    private var circleRadius: Float
    @ColorInt
    private val circleColor: Int
    private var circleSpacing: Float
    private val numberOfCircles: Int
    private val circlePaint: Paint
    private var percentage: Int = 0

    init {

        val styledAttributes = context.obtainStyledAttributes(
                attrs,
                R.styleable.ProfitabilityIndexView,
                0,
                R.style.ProfitabilityIndexViewStyle
        )

        circleRadius = styledAttributes.getDimension(
                R.styleable.ProfitabilityIndexView_pi_circle_radius,
                0f
        )

        circleColor = styledAttributes.getColor(
                R.styleable.ProfitabilityIndexView_pi_circle_color,
                0
        )

        circleSpacing = styledAttributes.getDimension(
                R.styleable.ProfitabilityIndexView_pi_circle_spacing,
                0f
        )

        numberOfCircles = styledAttributes.getInt(
                R.styleable.ProfitabilityIndexView_pi_number_of_circles,
                DEFAULT_NUMBER_OF_CIRCLES)

        val percentage = styledAttributes.getInt(
                R.styleable.ProfitabilityIndexView_pi_percentage,
                0
        )

        checkPercentageBounds(percentage)
        this.percentage = percentage

        circlePaint = Paint(ANTI_ALIAS_FLAG).apply {
            color = circleColor
        }

        styledAttributes.recycle()
    }

    override fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec)
        val width = paddingStart + getDrawnRegionSize() + paddingEnd
        val height = paddingBottom + paddingTop + 2 * circleRadius
        setMeasuredDimension(Math.round(width), Math.round(height))
    }

    override fun onDraw(canvas: Canvas) {
        clipPercentageBounds(canvas)
        drawCircles(canvas)
    }

    fun setPercentage(value: Int) {
        checkPercentageBounds(value)
        percentage = value
        invalidate()
    }

    fun setSpacing(value: Int) {
        circleSpacing = convertToPx(value).toFloat()
        requestLayout()
    }

    fun setRadius(value: Int) {
        circleRadius = convertToPx(value).toFloat()
        requestLayout()
    }

    fun getPercentage() = percentage

    @Suppress("DEPRECATION")
    private fun clipPercentageBounds(canvas: Canvas) {
        with(rect) {
            left = 0f
            top = paddingTop.toFloat()
            right = paddingLeft + getDrawnRegionSize() * percentage / 100
            bottom = paddingTop + circleRadius * 2
        }
        canvas.clipRect(rect)
    }

    private fun drawCircles(canvas: Canvas) {
        var dx = paddingStart.toFloat()

        for (i in 1..numberOfCircles) {
            canvas.drawOval(dx,
                    paddingTop.toFloat(),
                    dx + circleRadius * 2,
                    paddingTop + circleRadius * 2,
                    circlePaint
            )
            dx += circleRadius * 2 + circleSpacing
        }
    }

    private fun checkPercentageBounds(value: Int) {
        if (value < 0 || value > 100)
            throw IllegalArgumentException("Profitability view only accepts values in range 0..100")
    }

    private fun convertToPx(dp: Int): Int {
        val scale = resources.displayMetrics.density
        return (dp * scale + 0.5f).toInt()
    }

    private fun getDrawnRegionSize() =
            numberOfCircles * 2 * circleRadius + (numberOfCircles - 1) * circleSpacing
}