element-ios/Riot/Modules/SecureBackup/Setup/Intro/SecureKeyBackupSetupIntroCell.swift

/*
 Copyright 2020 New Vector Ltd
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
 You may obtain a copy of the License at
 
 http://www.apache.org/licenses/LICENSE-2.0
 
 Unless required by applicable law or agreed to in writing, software
 distributed under the License is distributed on an "AS IS" BASIS,
 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
 limitations under the License.
 */

import UIKit
import Reusable

final class SecureKeyBackupSetupIntroCell: UIView, NibOwnerLoadable, Themable {
    
    // MARK: - Constants
    
    private enum ImageAlpha {
        static let highlighted: CGFloat = 0.3
    }
    
    // MARK: - Properties
    
    // MARK: Outlets
    
    @IBOutlet private weak var backgroundView: UIView!
    @IBOutlet private weak var imageView: UIImageView!
    @IBOutlet private weak var titleLabel: UILabel!
    @IBOutlet private weak var informationLabel: UILabel!
    @IBOutlet private weak var accessoryImageView: UIImageView!
    @IBOutlet private weak var separatorView: UIView!
    
    // MARK: Private
    
    private var theme: Theme?
    
    private var isHighlighted: Bool = false {
        didSet {
            self.updateView()
        }
    }
    
    // MARK: Public
    
    var action: (() -> Void)?
    
    // MARK: Setup
    
    private func commonInit() {
        self.setupGestureRecognizer()
        
        let accessoryTemplateImage = Asset.Images.disclosureIcon.image.withRenderingMode(.alwaysTemplate)
        self.accessoryImageView.image = accessoryTemplateImage
        self.accessoryImageView.highlightedImage = accessoryTemplateImage.vc_withAlpha(ImageAlpha.highlighted)
    }
    
    convenience init() {
        self.init(frame: CGRect.zero)
        self.commonInit()
    }
    
    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        self.loadNibContent()
        self.commonInit()
    }
    
    override init(frame: CGRect) {
        super.init(frame: frame)
        self.loadNibContent()
        self.commonInit()
    }
    
    // MARK: - Public
    
    func update(theme: Theme) {
        self.theme = theme
        
        self.backgroundView.backgroundColor = theme.backgroundColor
        self.imageView.tintColor = theme.textPrimaryColor
        self.titleLabel.textColor = theme.tintColor
        self.informationLabel.textColor = theme.textSecondaryColor
        self.accessoryImageView.tintColor = theme.textSecondaryColor
        self.separatorView.backgroundColor = theme.lineBreakColor
        
        self.updateView()
    }
    
    func fill(title: String, information: String, image: UIImage) {
        let templateImage = image.withRenderingMode(.alwaysTemplate)
        
        self.imageView.image = templateImage
        self.imageView.highlightedImage = templateImage.vc_withAlpha(ImageAlpha.highlighted)
        
        self.titleLabel.text = title
        self.informationLabel.text = information
        
        self.setupAccessibility(title: title, isEnabled: true)
        self.updateView()
    }
    
    // MARK: - Private
    
    private func setupAccessibility(title: String, isEnabled: Bool) {
        self.isAccessibilityElement = true
        self.accessibilityLabel = title
        self.accessibilityTraits = .button
        if !isEnabled {
            self.accessibilityTraits.insert(.notEnabled)
        }
    }
    
    private func setupGestureRecognizer() {
        let gestureRecognizer = UILongPressGestureRecognizer(target: self, action: #selector(buttonAction(_:)))
        gestureRecognizer.minimumPressDuration = 0
        self.addGestureRecognizer(gestureRecognizer)
    }
    
    private func updateView() {
        
        if let theme = self.theme {
            self.backgroundView.backgroundColor = self.isHighlighted ? theme.overlayBackgroundColor : theme.backgroundColor
        }
        
        self.imageView.isHighlighted = self.isHighlighted
        self.accessoryImageView.isHighlighted = self.isHighlighted
    }
    
    // MARK: - Actions
    
    @objc private func buttonAction(_ sender: UILongPressGestureRecognizer) {
        
        let isBackgroundViewTouched = sender.vc_isTouchingInside()
        
        switch sender.state {
        case .began, .changed:
            self.isHighlighted = isBackgroundViewTouched
        case .ended:
            self.isHighlighted = false
            
            if isBackgroundViewTouched {
                self.action?()
            }
        case .cancelled:
            self.isHighlighted = false
        default:
            break
        }
    }
    
}