enum TextStyle {

case title

case heading

case body

case serif

}

let textFieldAnimationDuration: TimeInterval = 0.3

let accessaryView = UIView()

var keyboardView: UIView?

// Delay timer to switch between keyboards

var kTimer: Timer?

var isSwitchingKeyboard = false

let styleKeyboard = TextStyleKeyboardView()

let leftIndentButtonMain = UIButton()

let rightIndentButtonMain = UIButton()

var textFormatBarButtonForiPad: UIBarButtonItem!

let accessoryViewHeight: CGFloat = 50

let styleKeyboardHeight: CGFloat = 300

let indentWidth: CGFloat = 20

let minimumIndent: CGFloat = 0

let maximumIndent: CGFloat = 200

struct TextState {

let selectedRange: NSRange

let attributedText: NSAttributedString

}

var keyboardHeight: CGFloat = 0.0

override public var selectedTextRange: UITextRange? {

didSet {

updateVisualForKeyboard()

}

}

public weak var hostingViewController: UIViewController?

public var shouldAdjustInsetBasedOnKeyboardHeight = false

public init() {

super.init(frame: .zero, textContainer: nil)

setupTextView()

}

public required init?(coder: NSCoder) {

super.init(coder: coder)

font = NotesFontProvider.shared.bodyFont

setupTextView()

}

override public func becomeFirstResponder() -> Bool {

let isAlreadyFirstResponder = isFirstResponder

let willBecomeFirstResponder = super.becomeFirstResponder()

if !isAlreadyFirstResponder && willBecomeFirstResponder {

if !isSwitchingKeyboard {

var targetLocationForAttributes: Int = 0

if selectedRange.location != NSNotFound && textStorage.length != 0 {

// selectedRange.Location is actually the length of the string so it becomes out of bounds when the selected range is actually at last character

if selectedRange.location == textStorage.length && selectedRange.length == 0 {

let lastChar = text.suffix(1) as NSString

targetLocationForAttributes = max(0, textStorage.length - lastChar.length)

// we don't need to update typing attributes here..

// it creates a problem if the last character is emoji. (emoji length is variable)

} else {

targetLocationForAttributes = selectedRange.location

typingAttributes = textStorage.attributes(at: targetLocationForAttributes, longestEffectiveRange: nil, in: selectedRange)

}

}

updateVisualForKeyboard()

}

}

return willBecomeFirstResponder

}

override public func resignFirstResponder() -> Bool {

let willResignFirstResponder = super.resignFirstResponder()

return willResignFirstResponder

}

override public func paste(_: Any?) {

// Setup code in overridden UITextView.copy/paste

let pb = UIPasteboard.general

// pasting from external source might paste some attributes like images, fonts, colors which are not supported.

// converting it to plain text to remove all the attributes and give it default font of body.

// UTI List

let utf8StringType = "public.utf8-plain-text"

for pbDict in pb.items {

if let pastedString = pbDict[utf8StringType] as? String {

// When pasting apply body font attributes

let attributes: [NSAttributedString.Key: Any] = [

NSAttributedString.Key.font: NotesFontProvider.shared.bodyFont,

NSAttributedString.Key.foregroundColor: UIColor.label,

]

let attributed = NSAttributedString(string: pastedString, attributes: attributes)

// how many characters to advance?

// string counts emojis as single character so don't use string.count

// convert it to NSString and check its length

let rawString = pastedString as NSString

// Insert pasted string

textStorage.insert(attributed, at: selectedRange.location)

selectedRange.location += rawString.length

selectedRange.length = 0

}

}

}

override public func shouldChangeText(in _: UITextRange, replacementText text: String) -> Bool {

// after the Title or Heading line,

// next line should be body font

if text == "\n" {

if let font = typingAttributes[NSAttributedString.Key.font] as? UIFont {

if font == NotesFontProvider.shared.headingFont || font == NotesFontProvider.shared.titleFont {

typingAttributes[NSAttributedString.Key.font] = NotesFontProvider.shared.bodyFont

updateVisualForKeyboard()

}

}

if typingAttributes[NSAttributedString.Key.backgroundColor] != nil {

typingAttributes[NSAttributedString.Key.backgroundColor] = UIColor.clear

}

}

return true

}

func setupTextView() {

typingAttributes[NSAttributedString.Key.font] = NotesFontProvider.shared.bodyFont

typingAttributes[NSAttributedString.Key.foregroundColor] = UIColor.label

alwaysBounceVertical = true

allowsEditingTextAttributes = true

keyboardDismissMode = .interactive

setupKeyboardActions()

if traitCollection.userInterfaceIdiom == .pad {

let Aa_IconConfig = UIImage.SymbolConfiguration(pointSize: 30, weight: .regular, scale: .small)

let textfomratImage = UIImage(systemName: "textformat.size", withConfiguration: Aa_IconConfig)

textFormatBarButtonForiPad = UIBarButtonItem(image: textfomratImage, style: .plain, target: self, action: #selector(showPopOverKeyboardForiPad))

let buttonGroup = UIBarButtonItemGroup(barButtonItems: [textFormatBarButtonForiPad], representativeItem: nil)

inputAssistantItem.trailingBarButtonGroups = [buttonGroup]

} else {

prepareAccessoryView()

}

NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow(notification:)), name: UIResponder.keyboardWillShowNotification, object: nil)

NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide(notification:)), name: UIResponder.keyboardWillHideNotification, object: nil)

NotificationCenter.default.addObserver(self, selector: #selector(textDidChange(_:)), name: UITextView.textDidChangeNotification, object: nil)

styleKeyboard.delegate = self

}

@objc private func textDidChange(_: Notification) {

updateVisualForKeyboard()

}

private func setupKeyboardActions() {

styleKeyboard.boldButton.addTarget(self, action: #selector(makeTextBold), for: .touchUpInside)

styleKeyboard.italicButton.addTarget(self, action: #selector(makeTextItalics), for: .touchUpInside)

styleKeyboard.underlineButton.addTarget(self, action: #selector(makeTextUnderline), for: .touchUpInside)

styleKeyboard.strikethroughButton.addTarget(self, action: #selector(makeTextStrikethrough), for: .touchUpInside)

styleKeyboard.leftIndentButton.addTarget(self, action: #selector(indentLeft), for: .touchUpInside)

styleKeyboard.rightIndentButton.addTarget(self, action: #selector(indentRight), for: .touchUpInside)

styleKeyboard.titleButton.tapGesture.addTarget(self, action: #selector(useTitle))

styleKeyboard.headingButton.tapGesture.addTarget(self, action: #selector(useHeading))

styleKeyboard.bodyButton.tapGesture.addTarget(self, action: #selector(useBody))

styleKeyboard.serifButton.tapGesture.addTarget(self, action: #selector(useSerif))

styleKeyboard.returnButton.addTarget(self, action: #selector(showDefaultKeyboard), for: .touchUpInside)

styleKeyboard.leftAlignButton.addTarget(self, action: #selector(useLeftAlignment), for: .touchUpInside)

styleKeyboard.centerAlignButton.addTarget(self, action: #selector(useCenterAlignment), for: .touchUpInside)

styleKeyboard.rightAlignButton.addTarget(self, action: #selector(useRightAlignment), for: .touchUpInside)

}

private func prepareAccessoryView() {

accessaryView.frame = .init(origin: .zero, size: CGSize(width: 10, height: accessoryViewHeight))

accessaryView.backgroundColor = .systemGray5

accessaryView.accessibilityIdentifier = "accessoryView"

inputAccessoryView = accessaryView

let Aa_IconConfig = UIImage.SymbolConfiguration(pointSize: 30, weight: .regular, scale: .small)

let indent_config = UIImage.SymbolConfiguration(pointSize: 25, weight: .regular, scale: .small)

let textFormatButton = UIButton()

let textfomratImage = UIImage(systemName: "textformat.size", withConfiguration: Aa_IconConfig)

textFormatButton.setImage(textfomratImage, for: .normal)

textFormatButton.addTarget(self, action: #selector(showStyleKeyboard), for: .touchUpInside)

let leftImage = UIImage(systemName: "decrease.indent", withConfiguration: indent_config)

let rightImage = UIImage(systemName: "increase.indent", withConfiguration: indent_config)

leftIndentButtonMain.setImage(leftImage, for: .normal)

rightIndentButtonMain.setImage(rightImage, for: .normal)

leftIndentButtonMain.addTarget(self, action: #selector(indentLeft), for: .touchUpInside)

rightIndentButtonMain.addTarget(self, action: #selector(indentRight), for: .touchUpInside)

leftIndentButtonMain.isEnabled = false

let indentStack = UIStackView(arrangedSubviews: [leftIndentButtonMain, rightIndentButtonMain])

indentStack.spacing = 20

textFormatButton.tintColor = .systemGray

leftIndentButtonMain.tintColor = .systemGray

rightIndentButtonMain.tintColor = .systemGray

accessaryView.addSubview(textFormatButton)

textFormatButton.anchor(top: accessaryView.topAnchor, leading: accessaryView.safeAreaLayoutGuide.leadingAnchor, bottom: accessaryView.bottomAnchor, trailing: nil, padding: .init(top: 0, left: 25, bottom: 0, right: 0))

accessaryView.addSubview(indentStack)

indentStack.anchor(top: accessaryView.topAnchor, leading: nil, bottom: accessaryView.bottomAnchor, trailing: accessaryView.safeAreaLayoutGuide.trailingAnchor, padding: .init(top: 0, left: 0, bottom: 0, right: 20))

}