yingmeng-ios-switf/yinmeng-ios/Modules/Chat/Keyboard/ChatGrowingTextView.swift

//
//  ChatGrowingTextView.swift
//  yinmeng-ios
//
//  Created by MaiMang on 2024/2/29.
//

import UIKit

class ChatGrowingTextView: UITextView {
	/// 行数部分间距调整
	fileprivate let kEdgeInset: CGFloat = 12
	/// 内容字体默认大小
	fileprivate let kDefultSize: CGFloat = 15.0

	// MARK: - var lazy

	/// 默认3行的高度
	fileprivate var maxTextViewHeight: CGFloat = 80

	var placeholder: String? = "" {
		didSet {
			self.placeholderLabel.text = placeholder
		}
	}

	var placeholderColor: UIColor? = .black {
		didSet {
			self.placeholderLabel.textColor = placeholderColor
		}
	}

	var maxNumberOfLines: Int = 3 {
		didSet {
			let numberOfLines = CGFloat(maxNumberOfLines)
			maxTextViewHeight = CGFloat(ceilf(Float(self.font!.lineHeight * numberOfLines + self.textContainerInset.top + self.textContainerInset.bottom))) - kEdgeInset
		}
	}



	/// 输入框高度监听回调
	var didTextChangedHeightClosure : ((CGFloat)->Void)?

	/// 占位标签
	fileprivate lazy var placeholderLabel: UILabel = {
		let frame = CGRect(x: 5, y: 7, width: ScreenWidth - 10, height: 21)
		let label = UILabel(frame: frame)
		label.numberOfLines = 1
		label.text = "请输入你要发送的消息"
		label.textColor = ThemeColor(hexStr: "#F6F6F6")
		label.font = UIFont.systemFont(ofSize: self.kDefultSize)
		return label
	}()

	// MARK: - life cycle

	override init(frame: CGRect, textContainer: NSTextContainer?) {
		super.init(frame: frame, textContainer: textContainer)

		setup()
	}

	required public init?(coder aDecoder: NSCoder) {
		fatalError("init(coder:) has not been implemented")
	}

	fileprivate func setup() {
		backgroundColor = .white

		self.isScrollEnabled = false
		self.scrollsToTop = false
		//self.contentInset = UIEdgeInsets(top: 1, left: 0, bottom: 1, right: 0)
		self.showsHorizontalScrollIndicator = false
		self.enablesReturnKeyAutomatically = true
		self.font = UIFont.systemFont(ofSize: kDefultSize)
		self.returnKeyType = .send

		self.layer.cornerRadius = 4
		self.layer.borderWidth = 1
		self.layer.borderColor = ThemeColor(hexStr: "#2C363E").cgColor
		self.layer.masksToBounds = true
		// 添加占位控件
		addSubview(self.placeholderLabel)

		// register
		registerChangeNotification()
	}

	fileprivate func registerChangeNotification() {
		// 实时监听输入值的改变
		NotificationCenter.default.addObserver(self,
											   selector: #selector(textDidChanged),
											   name: UITextView.textDidChangeNotification,
											   object: self)

		self.addObserver(self, forKeyPath: "attributedText", options: .new, context: nil)
	}

	// MARK: - KVO监听

	override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?) {
		if keyPath == "attributedText" {
			textDidChanged()
		}else {

			super.observeValue(forKeyPath: keyPath, of: object, change: change, context: context)
		}
	}


	deinit {
		NotificationCenter.default.removeObserver(self)
		self.removeObserver(self, forKeyPath: "attributedText")
	}

}

// MARK: - Action

extension ChatGrowingTextView {

	@objc func textDidChanged() {
		placeholderLabel.isHidden = self.hasText

		// 计算高度
		let constrainSize = CGSize(width: self.frame.size.width, height: CGFloat(MAXFLOAT))
		var size = self.sizeThatFits(constrainSize)

		if size.height >= maxTextViewHeight {
			self.isScrollEnabled = true
			size.height = maxTextViewHeight
		}else {
			self.isScrollEnabled = false
			if (didTextChangedHeightClosure != nil && !self.isScrollEnabled) {
				didTextChangedHeightClosure?(size.height)
			}
		}

		let nowFrame = self.frame
		frame.size.height = size.height
		self.frame = nowFrame

		self.layoutIfNeeded()

		sendChangedNoti()
	}

	func sendChangedNoti() {

		NotificationCenter.default.post(name: .kChatTextKeyboardChanged, object: self.text, userInfo: nil)
	}
}