new/CommonFrame/IQKeyboardManagerSwift/IQToolbar/IQBarButtonItem.swift

//
//  IQBarButtonItem.swift
// https://github.com/hackiftekhar/IQKeyboardManager
// Copyright (c) 2013-16 Iftekhar Qurashi.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

import UIKit
import Foundation

open class IQBarButtonItem: UIBarButtonItem {

    private static var _classInitialize: Void = classInitialize()

    @objc public override init() {
        _ = IQBarButtonItem._classInitialize
          super.init()
      }

    @objc public required init?(coder aDecoder: NSCoder) {
        _ = IQBarButtonItem._classInitialize
           super.init(coder: aDecoder)
       }

    private class func classInitialize() {

        let  appearanceProxy = self.appearance()

        #if swift(>=4.2)
        let states: [UIControl.State]
        #else
        let states: [UIControlState]
        #endif

        states = [.normal, .highlighted, .disabled, .selected, .application, .reserved]

        for state in states {

            appearanceProxy.setBackgroundImage(nil, for: state, barMetrics: .default)
            appearanceProxy.setBackgroundImage(nil, for: state, style: .done, barMetrics: .default)
            appearanceProxy.setBackgroundImage(nil, for: state, style: .plain, barMetrics: .default)
            appearanceProxy.setBackButtonBackgroundImage(nil, for: state, barMetrics: .default)
        }

        appearanceProxy.setTitlePositionAdjustment(UIOffset(), for: .default)
        appearanceProxy.setBackgroundVerticalPositionAdjustment(0, for: .default)
        appearanceProxy.setBackButtonBackgroundVerticalPositionAdjustment(0, for: .default)
    }

    @objc override open var tintColor: UIColor? {
        didSet {

            #if swift(>=4.2)
            var textAttributes = [NSAttributedString.Key: Any]()
            let foregroundColorKey = NSAttributedString.Key.foregroundColor
            #elseif swift(>=4)
            var textAttributes = [NSAttributedStringKey: Any]()
            let foregroundColorKey = NSAttributedStringKey.foregroundColor
            #else
            var textAttributes = [String: Any]()
            let foregroundColorKey = NSForegroundColorAttributeName
            #endif

            textAttributes[foregroundColorKey] = tintColor

            #if swift(>=4)

                if let attributes = titleTextAttributes(for: .normal) {

                    for (key, value) in attributes {
                        #if swift(>=4.2)
                        textAttributes[key] = value
                        #else
                        textAttributes[NSAttributedStringKey.init(key)] = value
                        #endif
                    }
                }

            #else

                if let attributes = titleTextAttributes(for: .normal) {
                    textAttributes = attributes
                }
            #endif

            setTitleTextAttributes(textAttributes, for: .normal)
        }
    }

    /**
     Boolean to know if it's a system item or custom item, we are having a limitation that we cannot override a designated initializer, so we are manually setting this property once in initialization
     */
    @objc internal var isSystemItem = false

    /**
     Additional target & action to do get callback action. Note that setting custom target & selector doesn't affect native functionality, this is just an additional target to get a callback.
     
     @param target Target object.
     @param action Target Selector.
     */
    @objc open func setTarget(_ target: AnyObject?, action: Selector?) {
        if let target = target, let action = action {
            invocation = IQInvocation(target, action)
        } else {
            invocation = nil
        }
    }

    /**
     Customized Invocation to be called when button is pressed. invocation is internally created using setTarget:action: method.
     */
    @objc open var invocation: IQInvocation?

    deinit {
        target = nil
        invocation = nil
    }
}