IQKeyboardManager 源代码看看

IQKeyboardManager 三步走

大家都用 IQKeyboardManager，

IQKeyboardManager 引入，就管理好了

第 1 步，注册系统通知，获得键盘事件

从键盘事件中，得到输入文本框对象， UITextField / UITextView 的实例

IQKeyboardManager 初始化的时候，就完成了这些

第 2 步，计算出当前文本框的位置， 并移动

有了文本框，要找到他当前的位置，frame

就要从文本框溯源，找到他的根视图控制器

然后计算出当前文本框在哪个位置合适，

移动过去，就好了

2.1 , 计算出合适的位置

先算出，该文本框在根视图的位置

再算出，该文本框在当前窗口, KeyWindow， 中的合适位置

2.2，键盘出现，与键盘消失

开始编辑，键盘出现，移动位置

结束编辑，键盘消失，还原位置

3，情况判断

UIView 上放置几个 UITextField / UITextView ，好处理

UIView 上放置 UITableView, UITableView 上的一个 cell，上面摆放 UITextField / UITextView，就复杂了一些

3.1 特殊类处理，

对于 UIAlertController 的输入框，不用处理

比较特殊的，还有 UITableViewController、UISearchBar、

_UIAlertControllerTextFieldViewController

0， 键盘管理，很简单

对于一个输入框 UITextField , 放置在 UIView 上，

键盘出来了，这个 UITextField 的位置，要适当，

通过两个通知处理掉，

一般情况下，键盘出来，把 UITextField 位置放高一点，

键盘消失，把 UITextField 位置放回原处

    import SnapKit
    
    // 注册通知
    func config(){
        NotificationCenter.default.addObserver(self,
                             selector: #selector(self.keyboardWillShow(noti:)),
                             name: UIWindow.keyboardWillShowNotification,
                             object: nil)
        NotificationCenter.default.addObserver(self,
                             selector: #selector(self.keyboardWillHide(noti:)),
                             name: UIWindow.keyboardWillHideNotification,
                             object: nil)
    }
    
    
    // 放高一点
    @objc
    func keyboardWillShow(noti notification: NSNotification){
        yConstraint?.constraint.update(offset: s.height * (-0.5))
        layoutIfNeeded()
    }
    
    
    
    // 放回原处
    @objc
    func keyboardWillHide(noti notification: NSNotification){
        yConstraint?.constraint.update(offset: 0)
        layoutIfNeeded()
    }

对于 UITextView，也这样处理

IQKeyboardManager 做的工作，就复杂、全面了很多

---

1， 初始化工作

注册 4 个键盘通知，

键盘将要出现，键盘出现了，

键盘将要消失，键盘消失了，

输入文本框，有两种，UITextField 和 UITextView

再注册两个 UITextField 的通知，两个 UITextView 的通知

最后注册一个屏幕旋转的通知

@objc func registerAllNotifications() {

        //  Registering for keyboard notification.
        NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardWillShow(_:)), name: UIKeyboardWillShowNotification, object: nil)
        NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardDidShow(_:)), name: UIKeyboardDidShowNotification, object: nil)
        NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardWillHide(_:)), name: UIKeyboardWillHideNotification, object: nil)
        NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardDidHide(_:)), name: UIKeyboardDidHideNotification, object: nil)

        //  Registering for UITextField notification.
        registerTextFieldViewClass(UITextField.self, didBeginEditingNotificationName: UITextFieldTextDidBeginEditingNotification.rawValue, didEndEditingNotificationName: UITextFieldTextDidEndEditingNotification.rawValue)

        //  Registering for UITextView notification.
        registerTextFieldViewClass(UITextView.self, didBeginEditingNotificationName: UITextViewTextDidBeginEditingNotification.rawValue, didEndEditingNotificationName: UITextViewTextDidEndEditingNotification.rawValue)

        //  Registering for orientation changes notification
        NotificationCenter.default.addObserver(self, selector: #selector(self.willChangeStatusBarOrientation(_:)), name: UIApplicationWillChangeStatusBarOrientationNotification, object: UIApplication.shared)
    }

我们使用自动键盘，这样来一下

IQKeyboardManager.shared.enable = true

激活了内部的功能使用，状态判断

func privateIsEnabled() -> Bool {
        // 这里用到了，我们设置的属性
        var isEnabled = enable

        let enableMode = textFieldView?.enableMode

        if enableMode == .enabled {
            isEnabled = true
        } else if enableMode == .disabled {
            isEnabled = false
        } else if var textFieldViewController = textFieldView?.viewContainingController() {
            // 走这里
            //If it is searchBar textField embedded in Navigation Bar
            if textFieldView?.textFieldSearchBar() != nil, let navController = textFieldViewController as? UINavigationController, let topController = navController.topViewController {
                textFieldViewController = topController
            }

            //If viewController is kind of enable viewController class, then assuming it's enabled.
            if !isEnabled, enabledDistanceHandlingClasses.contains(where: { textFieldViewController.isKind(of: $0) }) {
                isEnabled = true
            }

            // ...
        }
        // 这里起作用
        return isEnabled
    }

---

2， 计算位置，与修改

2.1， 点击一个文本框 UITextField，先走输入框通知的方法

输入框开始编辑

从得到的通知中，取得输入框的对象，使用关联的属性，保存起来

// 注册通知
@objc public func registerTextFieldViewClass(_ aClass: UIView.Type, didBeginEditingNotificationName: String, didEndEditingNotificationName: String) {

        NotificationCenter.default.addObserver(self, selector: #selector(self.textFieldViewDidBeginEditing(_:)), name: Notification.Name(rawValue: didBeginEditingNotificationName), object: nil)
        // ...
    }
    
    
    
// 
@objc func textFieldViewDidBeginEditing(_ notification: Notification) {

        let startTime = CACurrentMediaTime()
        showLog("****** \(#function) started ******", indentation: 1)

        //  Getting object
        textFieldView = notification.object as? UIView
        
        // 下面是一些，去除重复状态的工作
}

2.2， 再走键盘将要出现的方法

 // 键盘出现的通知
 @objc func registerAllNotifications() {

        //  Registering for keyboard notification.
        NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardWillShow(_:)), name: UIKeyboardWillShowNotification, object: nil)
        // ...
}


// 键盘出现，调整位置
@objc internal func keyboardWillShow(_ notification: Notification?) {
     // ...
             if keyboardShowing,
                let textFieldView = textFieldView,
                textFieldView.isAlertViewTextField() == false {

                //  keyboard is already showing. adjust position.
                //  调整位置
                optimizedAdjustPosition()
            }
     // ...
}

2.3， 去调整位置

通过属性记录，hasPendingAdjustRequest, 一次调整必须完成，再来下一个

internal func optimizedAdjustPosition() {
        if !hasPendingAdjustRequest {
            hasPendingAdjustRequest = true
            OperationQueue.main.addOperation {
                self.adjustPosition()
                self.hasPendingAdjustRequest = false
            }
        }
    }

先做坐标转换，

找出合适的移动距离，

再判断情况，

最后去移动，

移动就是把父视图的坐标原点改下，与 前面的 0 ，键盘管理 一样

private func adjustPosition() {

         // 坐标转换

        //  We are unable to get textField object while keyboard showing on WKWebView's textField.  (Bug ID: #11)
        guard hasPendingAdjustRequest,
            let textFieldView = textFieldView,
            let rootController = textFieldView.parentContainerViewController(),
            let window = keyWindow(),
            let textFieldViewRectInWindow = textFieldView.superview?.convert(textFieldView.frame, to: window),
            let textFieldViewRectInRootSuperview = textFieldView.superview?.convert(textFieldView.frame, to: rootController.view?.superview) else {
                return
        }
        // ...
        // 计算初步移动距离
        var move: CGFloat = min(textFieldViewRectInRootSuperview.minY-(topLayoutGuide), textFieldViewRectInWindow.maxY-(window.frame.height-kbSize.height)+bottomLayoutGuide)
        // 情况判断
        // ...
        // 上移部分
        
        //  +Positive or zero.
        if move >= 0 {

            rootViewOrigin.y = max(rootViewOrigin.y - move, min(0, -(kbSize.height-newKeyboardDistanceFromTextField)))

            if rootController.view.frame.origin.equalTo(rootViewOrigin) == false {
                showLog("Moving Upward")

                UIView.animate(withDuration: animationDuration, delay: 0, options: animationCurve, animations: { () -> Void in

                    var rect = rootController.view.frame
                    rect.origin = rootViewOrigin
                    rootController.view.frame = rect

                    //Animating content if needed (Bug ID: #204)
                    if self.layoutIfNeededOnUpdate {
                        //Animating content (Bug ID: #160)
                        rootController.view.setNeedsLayout()
                        rootController.view.layoutIfNeeded()
                    }

                    self.showLog("Set \(rootController) origin to: \(rootViewOrigin)")
                })
            }

            movedDistance = (topViewBeginOrigin.y-rootViewOrigin.y)
        } else {  //  -Negative
        
        // 还有下移部分
        
        }
        

2.4 坐标转换，找出位置

上面的代码

guard hasPendingAdjustRequest,
            let textFieldView = textFieldView,
            let rootController = textFieldView.parentContainerViewController(),
            let textFieldViewRectInRootSuperview = textFieldView.superview?.convert(textFieldView.frame, to: rootController.view?.superview) else {
                return
        }

拿到了一个输入框 UITextField / UITextView,

先取得其父响应者中，第一个视图控制器，

拿到第一个视图控制器, 找到当前根视图控制器，

（ 因为可能一个控制器的子控制器的视图上，放了一个文本框 ）

@objc public extension UIView {

    // 从输入框，到控制器
    func viewContainingController() -> UIViewController? {

        var nextResponder: UIResponder? = self

        repeat {
            nextResponder = nextResponder?.next

            if let viewController = nextResponder as? UIViewController {
                return viewController
            }

        } while nextResponder != nil

        return nil
    }



    // 从控制器，到当前根视图控制器，
    // 这个方法，没有使用递归，只是简单的往前翻
func parentContainerViewController() -> UIViewController? {

        var matchController = viewContainingController()
        var parentContainerViewController: UIViewController?

        if var navController = matchController?.navigationController {

            while let parentNav = navController.navigationController {
                navController = parentNav
            }

            var parentController: UIViewController = navController

            while let parent = parentController.parent,
                (parent.isKind(of: UINavigationController.self) == false &&
                    parent.isKind(of: UITabBarController.self) == false &&
                    parent.isKind(of: UISplitViewController.self) == false) {

                        parentController = parent
            }

            if navController == parentController {
                parentContainerViewController = navController.topViewController
            } else {
                parentContainerViewController = parentController
            }
        } else if let tabController = matchController?.tabBarController {

            if let navController = tabController.selectedViewController as? UINavigationController {
                parentContainerViewController = navController.topViewController
            } else {
                parentContainerViewController = tabController.selectedViewController
            }
        } else {
            while let parentController = matchController?.parent,
                (parentController.isKind(of: UINavigationController.self) == false &&
                    parentController.isKind(of: UITabBarController.self) == false &&
                    parentController.isKind(of: UISplitViewController.self) == false) {

                        matchController = parentController
            }

            parentContainerViewController = matchController
        }

        let finalController = parentContainerViewController?.parentIQContainerViewController() ?? parentContainerViewController

        return finalController

    }
    
    
}

坐标转换，找出位置，简单的 convert 下

2.4， 再走键盘出现了的方法

 @objc internal func keyboardDidShow(_ notification: Notification?) {
        // 功能激活控制
        if privateIsEnabled() == false {
            return
        }
        
        let startTime = CACurrentMediaTime()
        showLog("****** \(#function) started ******", indentation: 1)
        
        if let textFieldView = _textFieldView,
            let parentController = textFieldView.parentContainerViewController(), (parentController.modalPresentationStyle == UIModalPresentationStyle.formSheet || parentController.modalPresentationStyle == UIModalPresentationStyle.pageSheet){
            
            self.optimizedAdjustPosition()
        }
        // ...

    }

3 应用： （ 情况判断部分，略）

控制器里面，采用了自定制的头部视图，

键盘出现，自定制的头部视图不动，其他部分照常动

3.1 解决

用到的控制器，继承自 BaseC，

键盘相关的视图，添加在 contentView 上

class BaseC: UIViewController {

    
    
    var contentView :UIView = {
        let w = UIView()
        w.backgroundColor = .clear
        return w
    }()
    
    
    var firstLoad = true
    
    
    var contentFrame: CGRect{
        get{
            contentView.frame
        }
        set{
            contentView.frame = newValue
        }
    }
    

    
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        view.addSubview(contentView)
        
    }
    

 
    override func viewDidLayoutSubviews() {
        super.viewDidLayoutSubviews()
        if firstLoad{
            contentView.frame = view.frame
            firstLoad = false
        }
        
    }

}

• IQKeyboardManager 原来使用的 controller.view ，一部分换成

controller.virtualView

查看适合的位置，沿用

let textFieldViewRectInRootSuperview = textFieldView.superview?.convert(textFieldView.frame, to: rootController.view.superview)

• IQKeyboardManager 原来修改位置的 controller.view.frame = ，

换成 controller.containerFrame

extension UIViewController{
    
    
    var containerFrame: CGRect{
        get{
            if let me = self as? BaseC{
                return me.contentFrame
            }
            else{
                return view.frame
            }
            
        }
        set{
            if let me = self as? BaseC{
                me.contentFrame = newValue
            }
            else{
                view.frame = newValue
            }
        }
        
        
    }
    
    
    
    var virtualView: UIView{
        if let v = self as? BaseC{
            return v.contentView
        }
        else{
            return view
        }
        
    }
    
}

具体代码，见 github repo