SegmentedProgressBar3.kt

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

    @get:ColorInt
    var segmentColor: Int = Color.WHITE
    var segmentAlpha: Float = 1f
    var segmentCount: Int = 1
    var spacing: Float = 0f

    private val segmentPaints: MutableList<Paint> = mutableListOf()
    private val segmentPaths: MutableList<Path> = mutableListOf()
    private val segmentCoordinatesComputer: SegmentCoordinatesComputer = SegmentCoordinatesComputer()
    
    init {
        initSegmentPaths()
    }

    override fun onDraw(canvas: Canvas) {
        val w = width.toFloat()
        val h = height.toFloat()

        (0 until segmentCount).forEach { position ->
            val path = segmentPaths[position]
            val paint = segmentPaints[position]
            val segmentCoordinates = segmentCoordinatesComputer.segmentCoordinates(position, segmentCount, w, spacing)

            drawSegment(canvas, path, paint, segmentCoordinates, segmentColor, segmentAlpha)
        }
    }

    private fun initSegmentPaths() {
        (0 until segmentCount).forEach { _ ->
            segmentPaths.add(Path())
            segmentPaints.add(Paint(Paint.ANTI_ALIAS_FLAG))
        }
    }

    private fun drawSegment(canvas: Canvas, path: Path, paint: Paint, coordinates: SegmentCoordinates, color: Int, alpha: Float) {
        path.run {
            reset()
            moveTo(coordinates.topLeftX, 0f)
            lineTo(coordinates.topRightX, 0f)
            lineTo(coordinates.bottomRightX, height.toFloat())
            lineTo(coordinates.bottomLeftX, height.toFloat())
            close()
        }

        paint.color = color
        paint.alpha = alpha.toAlphaPaint()

        canvas.drawPath(path, paint)
    }
}