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
    
    /// Set this property if you want updateView to update the font based on this standard and the size passed in.
    public var standardFontSize: CGFloat = 0.0
    
    public var isShowingPlaceholder = true
    
    /// Set to true to hide the blinking textField cursor.
    public var hideBlinkingCaret = false
    
    private var textTraits: (color: UIColor, font: UIFont) = (color: .mvmBlack, font: MFStyler.fontRegularBodySmall())
    private var placeholderTraits: (text: String, color: UIColor, font: UIFont) = (text: "", color: .mvmCoolGray3, font: MFStyler.fontRegularMicro() )
    
    //--------------------------------------------------
    // MARK: - Delegate
    //--------------------------------------------------
    
    /// Holds a reference to the delegating class so this class can internally influence the TextField behavior as well.
    public weak var didDeleteDelegate: TextFieldDidDeleteProtocol?
    
    /// 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(placeholderText: String, delegate: UITextViewDelegate?) {
        self.init(frame: .zero, textContainer: nil)
        self.delegate = delegate
        self.placeholderTraits.text = placeholderText
    }
    
    public func initialSetup() {
        
        if !initialSetupPerformed {
            tintColor = .mvmBlack
            initialSetupPerformed = true
            setupView()
        }
    }
    
    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()
    }
    
    open func setTextViewState() {
        
        if isShowingPlaceholder {
            text = ""
            font = textTraits.font
            textColor = textTraits.color
            isShowingPlaceholder = false
        } else if text.isEmpty {
            isShowingPlaceholder = true
            textColor = placeholderTraits.color
            text = placeholderTraits.text
            font = placeholderTraits.font
        }
    }
    
    //--------------------------------------------------
    // MARK: - UITextViewDelegate
    //--------------------------------------------------
    
    //#pragma Mark UITextView Delegate methods forwarding
    @objc public func textViewShouldBeginEditing(_ textView: UITextView) -> Bool {
        
        return proprietorTextDelegate?.textViewShouldBeginEditing?(textView) ?? true
    }
    
    @objc public func textViewDidBeginEditing(_ textView: UITextView) {
        
        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) {
        
        setTextViewState()
        
        proprietorTextDelegate?.textViewDidChange?(textView)
    }
    
    @objc public func textViewShouldEndEditing(_ textView: UITextView) -> Bool {
        
        return proprietorTextDelegate?.textViewShouldEndEditing?(textView) ?? true
    }
    
    @objc public func textViewDidEndEditing(_ textView: UITextView) {
        
        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
        backgroundColor = .clear
        clipsToBounds = true
        smartQuotesType = .no
        smartDashesType = .no
        smartInsertDeleteType = .no
        font = textTraits.font
        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 }
        
        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
//         placeholderFont = model.placeholderFont
        text = model.text
        isShowingPlaceholder = model.text.isEmpty
        placeholderTraits.text = model.placeholder
        uiTextViewDelegate = delegateObject?.uiTextViewDelegate
        
        if let accessibilityText = model.accessibilityText {
            accessibilityLabel = accessibilityText
        }
        
        if let fontStyle = model.fontStyle?.rawValue {
            MFStyler.styleTextView(self, withStyle: fontStyle, genericScaling: false)
            standardFontSize = font?.pointSize ?? 0
            if let font = font {
                textTraits.font = font
            }
        } else {
            let fontSize = model.fontSize
            if let fontSize = fontSize {
                standardFontSize = fontSize
            }
            if let fontName = model.fontName {
                font = MFFonts.mfFont(withName: fontName, size: fontSize ?? standardFontSize)
            } else if let fontSize = fontSize {
                font = font?.updateSize(fontSize)
            }
        }
        
        if isEditable {
            MVMCoreUICommonViewsUtility.addDismissToolbar(to: self, delegate: delegateObject?.uiTextViewDelegate)
        }
    }
    
    open func reset() {
        
        setNeedsDisplay()
        backgroundColor = .clear
        text = ""
    }
}