mvm_core_ui/MVMCoreUI/BaseClasses/TextView.swift

//
//  TextView.swift
//  MVMCoreUI
//
//  Created by Kevin Christiano on 4/1/20.
//  Copyright © 2020 Verizon Wireless. All rights reserved.
//

import UIKit


@objc open class TextView: UITextView, UITextViewDelegate {
    //--------------------------------------------------
    // MARK: - Properties
    //--------------------------------------------------
    
    open var model: MoleculeModelProtocol?
    
    private var initialSetupPerformed = false
    
    /// If true then text textView is currently displaying the stored placeholder text as there is not content to display.
    public var isShowingPlaceholder = true
    
    /// Set to true to hide the blinking textField cursor.
    public var hideBlinkingCaret = false
    
    public var textViewModel: TextViewModel? {
        return model as? TextViewModel
    }
    
    //--------------------------------------------------
    // MARK: - Delegate
    //--------------------------------------------------
    
    /// Holds a reference to the delegating class so this class can internally influence the TextField behavior as well.
    public weak var didDeleteDelegate: TextInputDidDeleteProtocol?
    
    /// Holds a reference to the delegating class so this class can internally influence the TextField behavior as well.
    private weak var proprietorTextDelegate: UITextViewDelegate?
    
    /// If you're using a ViewController, you must set this to it.
    public weak var uiTextViewDelegate: UITextViewDelegate? {
        get { return delegate }
        set {
            delegate = self
            proprietorTextDelegate = newValue
        }
    }
    
    //--------------------------------------------------
    // MARK: - Constraint
    //--------------------------------------------------
    
    public var heightConstraint: NSLayoutConstraint?
    
    //--------------------------------------------------
    // MARK: - Initialization
    //--------------------------------------------------
    
    public override init(frame: CGRect, textContainer: NSTextContainer?) {
        super.init(frame: .zero, textContainer: nil)
        initialSetup()
    }
    
    public convenience init() {
        self.init(frame: .zero, textContainer: nil)
    }
    
    public required init?(coder: NSCoder) {
        super.init(coder: coder)
        initialSetup()
    }
    
    convenience init(delegate: UITextViewDelegate) {
        self.init(frame: .zero, textContainer: nil)
        self.delegate = delegate
    }
    
    //--------------------------------------------------
    // MARK: - Setup
    //--------------------------------------------------
    
    public func initialSetup() {
        
        if !initialSetupPerformed {
            tintColor = .mvmBlack
            initialSetupPerformed = true
            setupView()
        }
    }
    
    //--------------------------------------------------
    // MARK: - Methods
    //--------------------------------------------------
    
    /// Alters the blinking caret line as per design standards.
    open override func caretRect(for position: UITextPosition) -> CGRect {
        
        if hideBlinkingCaret {
            return .zero
        }
        
        let caretRect = super.caretRect(for: position)
        return CGRect(origin: caretRect.origin, size: CGSize(width: 1, height: caretRect.height))
    }
    
    open override func deleteBackward() {
        super.deleteBackward()
        didDeleteDelegate?.textFieldDidDelete()
    }
    
    public func setTextAppearance() {
        
        if isShowingPlaceholder {
            setTextContentTraits()
        }
    }
    
    public func setPlaceholderIfAvailable() {
        
        if let placeholder = textViewModel?.placeholder, !placeholder.isEmpty && text.isEmpty {
            setPlaceholderContentTraits()
        }
    }
    
    public func setTextContentTraits() {
        
        isShowingPlaceholder = false
        text = ""
        font = textViewModel?.fontStyle.getFont()
        textColor = textViewModel?.textColor.uiColor
    }
    
    public func setPlaceholderContentTraits() {
        
        isShowingPlaceholder = true
        textColor = textViewModel?.placeholderTextColor.uiColor
        font = textViewModel?.placeholderFontStyle.getFont()
        text = textViewModel?.placeholder
    }
    
    //--------------------------------------------------
    // MARK: - UITextViewDelegate
    //--------------------------------------------------
    
    @objc public func textViewShouldBeginEditing(_ textView: UITextView) -> Bool {
        
        return proprietorTextDelegate?.textViewShouldBeginEditing?(textView) ?? true
    }
    
    @objc public func textViewDidBeginEditing(_ textView: UITextView) {
        
        setTextAppearance()
        proprietorTextDelegate?.textViewDidBeginEditing?(textView)
    }
    
    @objc public func textView(_ textView: UITextView, shouldChangeTextIn range: NSRange, replacementText text: String) -> Bool {
        
        return proprietorTextDelegate?.textView?(textView, shouldChangeTextIn: range, replacementText: text) ?? true
    }
    
    @objc public func textViewDidChange(_ textView: UITextView) {
        
        textViewModel?.text = textView.text
        proprietorTextDelegate?.textViewDidChange?(textView)
    }
    
    @objc public func textViewShouldEndEditing(_ textView: UITextView) -> Bool {
        
        return proprietorTextDelegate?.textViewShouldEndEditing?(textView) ?? true
    }
    
    @objc public func textViewDidEndEditing(_ textView: UITextView) {
        
        setPlaceholderIfAvailable()
        proprietorTextDelegate?.textViewDidEndEditing?(textView)
    }
}

/// MARK:- MVMCoreViewProtocol
extension TextView: MVMCoreViewProtocol {
    
    open func updateView(_ size: CGFloat) { }
    
    /// Will be called only once.
    open func setupView() {
        
        translatesAutoresizingMaskIntoConstraints = false
        insetsLayoutMarginsFromSafeArea = false
        showsVerticalScrollIndicator = false
        showsHorizontalScrollIndicator = false
        contentInset = UIEdgeInsets(top: Padding.Three, left: Padding.Three, bottom: Padding.Three, right: Padding.Three)
        backgroundColor = .mvmWhite
        clipsToBounds = true
        smartQuotesType = .no
        smartDashesType = .no
        smartInsertDeleteType = .no
        font = textViewModel?.fontStyle.getFont()
        layer.borderWidth = 1
        layer.borderColor = UIColor.mvmBlack.cgColor
        isEditable = true
    }
}

/// MARK:- MoleculeViewProtocol
extension TextView: MoleculeViewProtocol {
    
    open func set(with model: MoleculeModelProtocol, _ delegateObject: MVMCoreUIDelegateObject?, _ additionalData: [AnyHashable: Any]?) {
        self.model = model
        
        if let color = model.backgroundColor?.uiColor {
            backgroundColor = color
        }
        
        guard let model = model as? TextViewModel else { return }
        
        heightConstraint?.isActive = false
        if let height = model.height {
            heightConstraint = heightAnchor.constraint(equalToConstant: height)
            heightConstraint?.isActive = true
        }
        
        isEditable = model.isEditable
        textAlignment = model.textAlignment
        textColor = model.textColor.uiColor
        layer.borderColor = model.borderColor?.cgColor
        layer.borderWidth = model.borderWidth
        text = model.text
        uiTextViewDelegate = delegateObject?.uiTextViewDelegate
        isShowingPlaceholder = model.text!.isEmpty
        
        if let accessibilityText = model.accessibilityText {
            accessibilityLabel = accessibilityText
        }
        
        font = model.fontStyle.getFont()
        setPlaceholderIfAvailable()
        
        if isEditable {
            MVMCoreUICommonViewsUtility.addDismissToolbar(to: self, delegate: delegateObject?.uiTextViewDelegate)
        }
    }
    
    open func reset() {
        
        backgroundColor = .mvmWhite
        text = ""
        inputAccessoryView?.removeFromSuperview()
        layer.borderColor = UIColor.mvmBlack.cgColor
        contentInset = UIEdgeInsets(top: Padding.Three, left: Padding.Three, bottom: Padding.Three, right: Padding.Three)
        layer.borderWidth = 0
    }
}