RainbowStripes_Gradient.kt

return object : Drawable() {
    private val paint = Paint()

    init {
        val scaledWidth = RAINBOW_WIDTH * context.resources.displayMetrics.density
        val y1 = (Math.sin(2 * RAINBOW_ANGLE) / 2 * scaledWidth).toFloat()
        val x1 = (scaledWidth - Math.tan(RAINBOW_ANGLE) * y1).toFloat()
        paint.shader = LinearGradient(
            0f, 0f,
            x1, y1,
            colors, stops,
            Shader.TileMode.REPEAT
        )
    }

    override fun draw(canvas: Canvas) {
        canvas.drawRect(bounds, paint)
    }

    override fun setAlpha(alpha: Int) {}

    override fun getOpacity() = PixelFormat.OPAQUE

    override fun setColorFilter(colorFilter: ColorFilter?) {}
}