How to change NSSlider tickmarks color?

Question

I know should change the function drawTickMarks,but what should I do to change tickmarks color?

Answer 1

If you want them in different color, draw them in a different color.

Having an empty implementation of drawTickMarks() draws nothing.

Subclass NSSliderCell and set the cell class.

Then provide a drawing routine in drawTickMarks()

class CustomSliderCell: NSSliderCell {

    override func drawTickMarks() {

        guard let slider = controlView as? NSSlider, slider.numberOfTickMarks > 0 else {
            return
        }

        let tickWidth: CGFloat = 5
        let horizontalinset: CGFloat = 5
        let verticalinset: CGFloat = 1
        let drawRect = slider.bounds.insetBy(dx: horizontalinset, dy: verticalinset) //squish in slightly
        let step = drawRect.width/CGFloat(numberOfTickMarks-1) //classic fenceposts problem
        var mark = CGFloat(0)
        for _ in 0..<numberOfTickMarks {
            let blob = NSBezierPath(roundedRect: NSRect(x: mark + horizontalinset , y:verticalinset, width: tickWidth, height: tickWidth*2), xRadius: tickWidth/2.0, yRadius: tickWidth/2.0)
            NSColor.green.set()
            blob.fill()
            NSColor.darkGray.set()
            blob.stroke()
            mark += step
        }
    }

}

This one is a demo and far from perfect but should give you an ideas of what is needed.