vds_ios/VDS/Classes/Control.swift

//
//  Control.swift
//  VDS
//
//  Created by Matt Bruce on 7/22/22.
//

import Foundation
import UIKit
import Combine

@objc(VDSControl)
/// Base Class use to build Controls.
open class Control: UIControl, ViewProtocol, UserInfoable, Clickable {

    //--------------------------------------------------
    // MARK: - Combine Properties
    //--------------------------------------------------
    /// Set of Subscribers for any Publishers for this Control.
    open var subscribers = Set<AnyCancellable>()

    open var onClickSubscriber: AnyCancellable? {
        willSet {
            if let onClickSubscriber {
                onClickSubscriber.cancel()
            }
        }
    }
        
    //--------------------------------------------------
    // MARK: - Properties
    //--------------------------------------------------
    private var initialSetupPerformed = false
    
    /// Key of whether or not updateView() is called in setNeedsUpdate()
    open var shouldUpdateView: Bool = true
    
    open var userInfo = [String: Primitive]()
    
    /// Current Surface and this is used to pass down to child objects that implement Surfacable
    open var surface: Surface = .light { didSet { setNeedsUpdate() } }
    
    /// Whether this object is disabled or not
    open var disabled: Bool {
        get { !isEnabled }
        set {
            if !isEnabled != newValue {
                isEnabled = !newValue
            }
        }
    }
    
    /// Whether the Control is selected or not.
    open override var isSelected: Bool { didSet { setNeedsUpdate() } }
    
    open var touchUpInsideCount: Int = 0
    
    var isHighlightAnimating = false
    
    /// Whether the Control is highlighted or not..
    open override var isHighlighted: Bool {
        didSet {
            if isHighlightAnimating == false && touchUpInsideCount > 0 {
                isHighlightAnimating = true
                UIView.animate(withDuration: 0.1, animations: { [weak self] in
                    self?.setNeedsUpdate()
                }) { [weak self] _ in
                    //you update the view since this is typically a quick change
                    UIView.animate(withDuration: 0.1, animations: { [weak self] in
                        self?.setNeedsUpdate()
                        self?.isHighlightAnimating = false
                    })
                }
            }
        }
    }
    
    /// Whether the Control is enabled or not.
    open override var isEnabled: Bool { didSet { setNeedsUpdate(); isUserInteractionEnabled = isEnabled } }

    //--------------------------------------------------
    // MARK: - Initializers
    //--------------------------------------------------
    required public init() {
        super.init(frame: .zero)
        initialSetup()
    }
    
    public override init(frame: CGRect) {
        super.init(frame: .zero)
        initialSetup()
    }
    
    public required init?(coder: NSCoder) {
        super.init(coder: coder)
        initialSetup()
    }
    
    //--------------------------------------------------
    // MARK: - Lifecycle
    //--------------------------------------------------
    
    /// Executed on initialization for this Control.
    open func initialSetup() {
        if !initialSetupPerformed {
            initialSetupPerformed = true
            setup()
            setNeedsUpdate()
        }
    }
    
    open func setup() {
        backgroundColor = .clear
        translatesAutoresizingMaskIntoConstraints = false
        insetsLayoutMarginsFromSafeArea = false
    }
            
    /// Function used to make changes to the View based off a change events or from local properties.
    open func updateView() { }
    
    open func updateAccessibility() {
        if isSelected {
            accessibilityTraits.insert(.selected)
        } else {
            accessibilityTraits.remove(.selected)
        }
        
        if isEnabled {
            accessibilityTraits.remove(.notEnabled)
        } else {
            accessibilityTraits.insert(.notEnabled)
        }

    }
    
    /// Resets to default settings.
    open func reset() {
        backgroundColor = .clear
        surface = .light
        disabled = false
    }
    
    //--------------------------------------------------
    // MARK: - Overrides
    //--------------------------------------------------

    /// Implement accessibilityActivate on an element in order to handle the default action.
    /// - Returns: Based on whether the userInteraction is enabled.
    override open func accessibilityActivate() -> Bool {
        // Hold state in case User wanted isAnimated to remain off.
        guard isUserInteractionEnabled else { return false }
        sendActions(for: .touchUpInside)
        return true
    }

}