Simple swift color picker popover (iOS)

Question

Is there is a simple way to implement a color picker popover in swift? Are there any built-in libraries or UI elements that I could leverage for this purpose? I saw some c

Answer 1

ColorPickerViewImage

Based on Christian1313 answer, I added darker colors:

@IBDesignable final public class SwiftColorView: UIView {

weak var colorSelectedDelegate: ColorDelegate?

@IBInspectable public var numColorsX:Int =  10 {
    didSet {
        setNeedsDisplay()
    }
}

@IBInspectable public var numColorsY:Int = 18 {
    didSet {
        setNeedsDisplay()
    }
}

@IBInspectable public var coloredBorderWidth:Int = 10 {
    didSet {
        setNeedsDisplay()
    }
}

@IBInspectable public var showGridLines:Bool = false {
    didSet {
        setNeedsDisplay()
    }
}

weak var delegate: SwiftColorPickerDataSource?

public override func touchesBegan(_ touches: Set, with event: UIEvent?) {
    guard let touch = touches.first else { return }
    let location = touch.location(in: self)

    colorSelectedDelegate?.setStroke(color: colorAtPoint(point: location))
}

public override func touchesMoved(_ touches: Set, with event: UIEvent?) {
    guard let touch = touches.first else { return }
    let location = touch.location(in: self)

    colorSelectedDelegate?.setStroke(color: colorAtPoint(point: location))
}

public override func draw(_ rect: CGRect) {
    super.draw(rect)
    let lineColor = UIColor.gray
    let pS = patternSize()
    let w = pS.w
    let h = pS.h

    for y in 0.. UIColor
{

    if let ds = delegate {
        return ds.colorForPalletIndex(x: x, y: y, numXStripes: numColorsX, numYStripes: numColorsY)
    } else {

        var hue:CGFloat = CGFloat(x) / CGFloat(numColorsX)
        var fillColor = UIColor.white
        if (y==0)
        {
            if (x==(numColorsX-1))
            {
                hue = 1.0;
            }
            fillColor = UIColor(white: hue, alpha: 1.0);
        }
        else
        {
            if y < numColorsY / 2 {
                //dark
                let length = numColorsY / 2
                let brightness: CGFloat = CGFloat(y) / CGFloat(length)
                fillColor = UIColor(hue: hue, saturation: 1.0, brightness: brightness, alpha: 1.0)
            } else if y == numColorsY / 2 {
                // normal
                fillColor = UIColor(hue: hue, saturation: 1.0, brightness: 1.0, alpha: 1.0)
            } else {
                // light
                let length = numColorsY / 2 - 1
                let offset = y - length - 1
                let sat:CGFloat = CGFloat(1.0) - CGFloat(offset) / CGFloat(length + 1)
                print("sat", sat)
                fillColor = UIColor(hue: hue, saturation: sat, brightness: 1.0, alpha: 1.0)
            }
        }
        return fillColor
    }
}

func colorAtPoint(point: CGPoint) -> UIColor
{
    let pS = patternSize()
    let w = pS.w
    let h = pS.h
    let x = (point.x-CGFloat(coloredBorderWidth))/w
    let y = (point.y-CGFloat(coloredBorderWidth))/h
    return colorForRectAt(x: Int(x), y:Int(y))
}

private func patternSize() -> (w: CGFloat, h:CGFloat)
{
    let width = self.bounds.width-CGFloat(2*coloredBorderWidth)
    let height = self.bounds.height-CGFloat(2*coloredBorderWidth)

    let w = width/CGFloat(numColorsX)
    let h = height/CGFloat(numColorsY)
    return (w,h)
}

public override func prepareForInterfaceBuilder()
{
    print("Compiled and run for IB")
}

}