safe-ios/Multisig/UI/App/Theme.swift

//
//  Theme.swift
//  Multisig
//
//  Created by Dmitry Bespalov on 13.05.20.
//  Copyright © 2020 Gnosis Ltd. All rights reserved.
//

import Foundation
import UIKit
import SwiftUI

class Theme: ObservableObject {

    private var tableViewBackgroundColor: UIColor?

    func setUp() {
        // we don't set the image for the navbar (pdf) as it crashes the app;
        // we don't set the `translucent` property of navbar to false because
        // it crashes the app (SwiftUI).
        // but shadow works.
        UINavigationBar.appearance().shadowImage = nil
        UINavigationBar.appearance().tintColor = .primary
  
        // non-zero height view adds the bottom space to the table views
        UITableView.appearance().tableFooterView = UIView(frame: CGRect(x: 0, y: 0, width: 0, height: 100))
        // makes separators to take full width of the screen
        // (default is with offset)
        UITableView.appearance().separatorInset = UIEdgeInsets(top: 0, left: 0, bottom: 0, right: 0)
        UITableView.appearance().separatorColor = .separator
        // we don't touch the UITableView appearance background color
        // because it messes up the backgrounds when navigating in the app



        // Fix transparent navigation bar in iOS 15
        let appearance = UINavigationBarAppearance()
        let attributes = [NSAttributedString.Key.font: UIFont.gnoFont(forTextStyle: .headline)]
        appearance.titleTextAttributes = attributes
        let largeFont = UIFont.gnoFont(forTextStyle: .largeTitle)
        appearance.largeTitleTextAttributes = [NSAttributedString.Key.font: largeFont]
        if #available(iOS 15, *) {
            appearance.configureWithOpaqueBackground()
        }

        UINavigationBar.appearance().standardAppearance = appearance
        UINavigationBar.appearance().scrollEdgeAppearance = appearance

        let darkNavBar = UINavigationBar.appearance(for: .init(userInterfaceStyle: .dark))
        darkNavBar.barTintColor = .backgroundSecondary
        darkNavBar.isTranslucent = false

        let lightNavBar = UINavigationBar.appearance(for: .init(userInterfaceStyle: .light))
        lightNavBar.barTintColor = nil
        lightNavBar.isTranslucent = true
        
        UITabBarItem.appearance().setTitleTextAttributes([NSAttributedString.Key.font: UIFont.gnoFont(forTextStyle: .tabBarTitle)], for: .normal)
        UIBarButtonItem.appearance().setTitleTextAttributes([NSAttributedString.Key.font: UIFont.gnoFont(forTextStyle: .body)], for: .normal)

        UITableView.appearance().backgroundColor = .backgroundPrimary
        UITableView.appearance().tableFooterView = UIView()

        setDisplayMode()
    }

    private func setDisplayMode() {
        UIApplication.shared.windows.filter(\.isKeyWindow).first?.overrideUserInterfaceStyle = displayMode
    }

    var displayMode: UIUserInterfaceStyle {
        get {
            UIUserInterfaceStyle(rawValue: Int(AppSettings.displayMode)) ?? .unspecified
        }
        set {
            AppSettings.displayMode = Int32(newValue.rawValue)
            setDisplayMode()
        }
    }

}