Attractor/App/Document Controls UI/DocumentControlView.swift

//
//  DocumentControlView.swift
//  App
//
//  Created by James Magahern on 9/30/20.
//

import UIKit

class DocumentControlView: UIControl
{
    static public let controlHeight = CGFloat(48.0)
    
    let imageView = UIImageView(frame: .zero)
    let label = UILabel(frame: .zero)
    
    var drawsBottomSeparator: Bool = false {
        didSet { setNeedsLayout() }
    }
    
    internal let highlightView = UIView(frame: .zero)
    internal let separatorView = UIView(frame: .zero)
    
    init() {
        super.init(frame: .zero)
        
        addSubview(highlightView)
        addSubview(imageView)
        addSubview(label)
        addSubview(separatorView)
        
        tintColor = .label
        
        label.font = UIFont.preferredFont(forTextStyle: .body)
        label.textAlignment = .left
        
        imageView.contentMode = .center
        
        separatorView.backgroundColor = .secondarySystemFill
        highlightView.backgroundColor = .secondarySystemFill
        
        highlightView.isHidden = true
    }
    
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    override func sizeThatFits(_ size: CGSize) -> CGSize {
        CGSize(width: size.width, height: Self.controlHeight)
    }
    
    override func layoutSubviews() {
        super.layoutSubviews()
        
        highlightView.frame = bounds
        
        let padding: CGFloat = 18.0
        let imageSize: CGFloat = 24.0
        let bounds = self.bounds.inset(by: layoutMargins)
        imageView.frame = CGRect(
            x: bounds.minX + 6.0, y: 0.0,
            width: imageSize, height: imageSize
        ).centeredY(inRect: self.bounds)
        
        label.frame = CGRect(
            x: imageView.frame.maxX + padding, y: bounds.minY,
            width: bounds.width - imageView.frame.maxX - padding, height: bounds.height
        )
        
        let separatorHeight: CGFloat = 1.0
        if drawsBottomSeparator {
            separatorView.isHidden = false
            separatorView.frame = CGRect(
                x: self.bounds.minX, y: self.bounds.height - separatorHeight,
                width: self.bounds.width, height: separatorHeight
            )
        } else {
            separatorView.isHidden = true
        }
    }
    
    override func setTracking(_ tracking: Bool) {
        super.setTracking(tracking)
        highlightView.isHidden = !tracking
    }
}