LiveKnob SwiftUI Bridge

LiveKnob-SwiftUI.swift

//
//  LiveKnobSwiftUI.swift
//  ControlBud-SwiftUI
//
//  Created by Cem Olcay on 11/3/21.
//

import UIKit
import SwiftUI
import LiveKnob

struct LiveKnobRep: UIViewRepresentable {
    typealias UIViewType = LiveKnob
    var value: Binding<Double>
    var isEnabled: Binding<Bool>

    var minValue: Double = 0.0
    var maxValue: Double = 1.0
    var baseColor: UIColor = .black
    var pointerColor: UIColor = .black
    var progressColor: UIColor = .orange
    var baseLineWidth: CGFloat = 2.0
    var progressLineWidth: CGFloat = 2.0
    var pointerLineWidth: CGFloat = 2.0
    var controlType: LiveKnobControlType = .rotary

    var valueDidChange: ((Double) -> Void)?
    var didStartEditing: ((Double) -> Void)?
    var didEndEditing: ((Double) -> Void)?

    init(
        value: Binding<Double> = .constant(0.0),
        isEnabled: Binding<Bool> = .constant(true)) {
        self.value = value
        self.isEnabled = isEnabled
    }

    func makeCoordinator() -> Coordinator {
        return Coordinator(self)
    }

    func makeUIView(context: Context) -> LiveKnob {
        let knob = LiveKnob()
        knob.addTarget(context.coordinator, action: #selector(Coordinator.valueDidChange(sender:)), for: .valueChanged)
        knob.addTarget(context.coordinator, action: #selector(Coordinator.didStartEditing(sender:)), for: .editingDidBegin)
        knob.addTarget(context.coordinator, action: #selector(Coordinator.didEndEditing(sender:)), for: .editingDidEnd)
        return knob
    }

    func updateUIView(_ uiView: LiveKnob, context: Context) {
        uiView.isEnabled = isEnabled.wrappedValue
        uiView.value = Float(value.wrappedValue)
        uiView.minimumValue = Float(minValue)
        uiView.maximumValue = Float(maxValue)
        uiView.baseColor = baseColor
        uiView.pointerColor = pointerColor
        uiView.progressColor = progressColor
        uiView.baseLineWidth = baseLineWidth
        uiView.pointerLineWidth = pointerLineWidth
        uiView.progressLineWidth = progressLineWidth
        uiView.controlType = controlType
    }

    func range(minValue: Double = 0.0, maxValue: Double = 1.0) -> LiveKnobRep {
        var knob = self
        knob.minValue = minValue
        knob.maxValue = maxValue
        return knob
    }

    func colors(base: UIColor = .black, pointer: UIColor = .black, progress: UIColor = .orange) -> LiveKnobRep {
        var knob = self
        knob.baseColor = base
        knob.pointerColor = pointer
        knob.progressColor = progress
        return knob
    }

    func lineWidths(base: CGFloat = 2, pointer: CGFloat = 2, progress: CGFloat = 2) -> LiveKnobRep {
        var knob = self
        knob.baseLineWidth = base
        knob.pointerLineWidth = pointer
        knob.progressLineWidth = progress
        return knob
    }

    func type(_ controlType: LiveKnobControlType) -> LiveKnobRep {
        var knob = self
        knob.controlType = controlType
        return knob
    }


    func onValueChange(_ action: @escaping (Double) -> Void) -> LiveKnobRep {
        var knob = self
        knob.valueDidChange = action
        return knob
    }

    func onStartEditing(_ action: @escaping (Double) -> Void) -> LiveKnobRep {
        var knob = self
        knob.didStartEditing = action
        return knob
    }

    func onEndEditing(_ action: @escaping (Double) -> Void) -> LiveKnobRep {
        var knob = self
        knob.didEndEditing = action
        return knob
    }

    class Coordinator: NSObject {
        var control: LiveKnobRep

        init(_ control: LiveKnobRep) {
            self.control = control
        }

        @objc func valueDidChange(sender: LiveKnob) {
            control.value.wrappedValue = Double(sender.value)
            control.valueDidChange?(Double(sender.value))
        }

        @objc func didStartEditing(sender: LiveKnob) {
            control.didStartEditing?(Double(sender.value))
        }

        @objc func didEndEditing(sender: LiveKnob) {
            control.didEndEditing?(Double(sender.value))
        }
    }
}