RulerControl

RulerControl is a draggable, resizable UIControl that provides real world length measurement. It supports various units of length, but is most appropriate for measurements in centimeters or inches.

How to use

Measurement in real world units

Set up plane with device ppi:

let device = Device() // Open source DeviceKit provides ppi
if let ppi = device.pointsPerInch {
    let plane = Plane(pointsPerUnit: ppi, unit: .inch)
    rulerControl.plane = plane
    rulerControl.baseUnit = .centimeter
}
rulerControl.addTarget(self, action: #selector(rulerChanged), for: .valueChanged)
rulerControl.isContinuous = true

Measurement in relative units

Use just like a slider:

rulerControl.addTarget(self, action: #selector(rulerChanged), for: .valueChanged)

Customizable appearance and behavior

struct Defaults {
    static let thickness: CGFloat = 15.0
    static let color = UIColor.blue
    static let handleColor = UIColor.blue
    static let baseUnit: DistanceUnit = .centimeter
    static let hashMarkColor = UIColor.white
    static let handleSize = CGSize(width: 40.0, height: 120.0)
    static let handleLineWidth: CGFloat = 14.0
    static let minimumLineLength: CGFloat = 30.0 // Line segment never gets shorter than this
    static let isContinuous = false
    static let showActual = true
}