TouchCheck/TouchCheck.swift at master · rossbeale/TouchCheck · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
//
//  TouchCheck.swift
//  TouchDemo
//
//  Created by Ross Beale on 18/04/2018.
//  Copyright © 2018 Airbyte Ltd. All rights reserved.
//

import UIKit

private struct TouchNode {

    let view: UIView
    let touchView: UIView

    let height = 39
    let width = 39

    init(view: UIView) {
        self.view = view

        self.touchView = UIView(frame: CGRect(x: 0, y: 0, width: width, height: height))
        self.touchView.backgroundColor = UIColor.blue.withAlphaComponent(0.4)
        self.touchView.isUserInteractionEnabled = false
        self.touchView.center = view.center
    }
}

extension UIViewController {

    private func showControlSubviews() {
        // get all views
        let views = view.subviewsRecursive()
        let controlViews = views.filter { $0.isControl() }
        let controlNodes = controlViews.map { TouchNode(view: $0) }

        // find nodes
        for node in controlNodes {
            // add touch
            node.view.superview?.addSubview(node.touchView)
        }

        for node in controlNodes {
            // determine if touch node is too small
            var valid = true
            let klass = NSStringFromClass(type(of: node.view))

            if !["_UIButtonBarButton", "_UIModernBarButton"].contains(klass) {
                valid = valid && node.view.frame.contains(node.touchView.frame)

                if let touchViewWindowFrame0 = node.view.superview?.convert(node.view.frame, to: nil) {
                    valid = valid && !controlNodes.contains(where: {
                        if let touchViewWindowFrame1 = $0.view.superview?.convert($0.view.frame, to: nil) {
                            return $0.view != node.view && touchViewWindowFrame0.intersects(touchViewWindowFrame1)
                        }

                        return false
                    })
                }
            }

            // add overlay
            let subview = UIView(frame: node.view.frame)
            subview.backgroundColor = valid ? UIColor.green.withAlphaComponent(0.3) : UIColor.red.withAlphaComponent(0.3)
            subview.isUserInteractionEnabled = false
            node.view.superview?.insertSubview(subview, aboveSubview: node.touchView)
        }
    }

}

private extension UIView {

    func isControl() -> Bool {
        return self is UIControl || self.gestureRecognizers?.count ?? 0 == 1
    }

    func subviewsRecursive() -> [UIView] {
        return subviews + subviews.flatMap { $0.subviewsRecursive() }
    }

}

private let swizzling: (AnyClass, Selector, Selector) -> () = { forClass, originalSelector, swizzledSelector in
    let originalMethod = class_getInstanceMethod(forClass, originalSelector)
    let swizzledMethod = class_getInstanceMethod(forClass, swizzledSelector)
    method_exchangeImplementations(originalMethod!, swizzledMethod!)
}

private extension UIViewController {

    static let classInit: Void = {
        let originalSelector = #selector(viewDidAppear(_:))
        let swizzledSelector = #selector(swizzled_viewDidAppear(animated:))
        swizzling(UIViewController.self, originalSelector, swizzledSelector)
    }()

    @objc func swizzled_viewDidAppear(animated: Bool) {
        swizzled_viewDidAppear(animated: animated)

        showControlSubviews()
    }

}

public final class TouchCheck: NSObject {

    /// Defines if and when TouchCheck should be enabled.
    ///
    /// - always:    TouchCheck is always enabled.
    /// - never:     TouchCheck is never enabled.
    /// - debugOnly: TouchCheck is enabled while the `DEBUG` flag is set and enabled.
    @objc public enum Enabled: Int {
        case always
        case never
        case debugOnly
    }

    @objc private static var enabled: TouchCheck.Enabled = .never

    static var shouldEnable: Bool {
        guard enabled != .never else { return false }
        guard enabled != .debugOnly else {
            #if DEBUG
            return true
            #else
            return false
            #endif
        }
        return true
    }

    static public func configure(enabled: TouchCheck.Enabled) {
        self.enabled = enabled

        if shouldEnable {
            UIViewController.classInit
        }
    }

}