//
// Copyright 2023 Signal Messenger, LLC
// SPDX-License-Identifier: AGPL-3.0-only
//
public import SignalServiceKit
public extension Notification.Name {
static let themeDidChange = Notification.Name("ThemeDidChangeNotification")
}
public final class Theme {
private static var shared = Theme(themeDataStore: ThemeDataStore())
private let themeDataStore: ThemeDataStore
private init(themeDataStore: ThemeDataStore) {
self.themeDataStore = themeDataStore
}
public static func performInitialSetup(appReadiness: AppReadiness) {
appReadiness.runNowOrWhenAppDidBecomeReadySync {
// IOS-782: +[Theme shared] re-enterant initialization
// AppReadiness will invoke the block synchronously if the app is already ready.
// This doesn't work here, because we'll end up reenterantly calling +shared
// if the app is in dark mode and the first call to +[Theme shared] happens
// after the app is ready.
//
// It looks like that pattern is only hit in the share extension, but we're better off
// asyncing always to ensure the dependency chain is broken. We're okay waiting, since
// there's no guarantee that this block in synchronously executed anyway.
DispatchQueue.main.async {
Self.shared.notifyIfThemeModeIsNotDefault()
}
}
}
public class func setupSignalAppearance() {
let primaryIconColor = UIColor(
light: .ows_gray75,
lightHighContrast: .ows_gray75,
dark: .ows_gray15,
darkHighContrast: .ows_gray15,
)
UINavigationBar.appearance().barTintColor = UIColor.Signal.background
UINavigationBar.appearance().tintColor = primaryIconColor
UIToolbar.appearance().barTintColor = UIColor.Signal.background
UIToolbar.appearance().tintColor = primaryIconColor
// We do _not_ specify BarButton.appearance().tintColor because it is sufficient to specify
// UINavigationBar.appearance().tintColor. Furthermore, specifying the BarButtonItem's
// appearance makes it more difficult to override the navbar theme, e.g. how we _always_
// use dark theme in the media send flow and gallery views. If we were specifying
// barButton.appearance().tintColor we would then have to manually override each
// BarButtonItem's tint, rather than just the navbars.
//
// UIBarButtonItem.appearance.tintColor = Theme.primaryIconColor;
// Using UIText{View,Field}.appearance().keyboardAppearance crashes due to a bug in UIKit,
// so we don't do it.
UITableViewCell.appearance().tintColor = primaryIconColor
UIToolbar.appearance().tintColor = .ows_accentBlue
// If we set NSShadowAttributeName, the NSForegroundColorAttributeName value is ignored.
UINavigationBar.appearance().titleTextAttributes = [
.foregroundColor: UIColor.Signal.label,
]
let cursorColor = UIColor(
light: .Signal.accent,
lightHighContrast: .Signal.accent,
dark: .white,
darkHighContrast: .white,
)
UITextView.appearance(whenContainedInInstancesOf: [OWSNavigationController.self]).tintColor = cursorColor
UITextField.appearance(whenContainedInInstancesOf: [OWSNavigationController.self]).tintColor = cursorColor
}
// MARK: - Theme Mode
public static var isDarkThemeEnabled: Bool { shared.isDarkThemeEnabled }
public class func getOrFetchCurrentMode() -> ThemeDataStore.Appearance {
return shared.getOrFetchCurrentMode()
}
public class func setCurrentMode(_ mode: ThemeDataStore.Appearance) {
shared.setCurrentMode(mode)
}
public class func performWithModeAsCurrent(_ mode: ThemeDataStore.Appearance, _ operation: () -> Void) {
shared.performWithModeAsCurrent(mode, operation)
}
private func performWithModeAsCurrent(_ mode: ThemeDataStore.Appearance, _ operation: () -> Void) {
let previousMode = cachedCurrentMode
defer { cachedCurrentMode = previousMode }
cachedCurrentMode = mode
operation()
}
private var cachedIsDarkThemeEnabled: Bool?
private var cachedCurrentMode: ThemeDataStore.Appearance?
public static var shareExtensionInterfaceStyleOverride: UIUserInterfaceStyle = .unspecified {
didSet {
owsPrecondition(
CurrentAppContext().isShareExtension,
"Must only be set in the share extension!",
)
if oldValue != shareExtensionInterfaceStyleOverride {
shared.themeDidChange()
}
}
}
private var isDarkThemeEnabled: Bool {
#if TESTABLE_BUILD
if let isDarkThemeEnabledForTests {
return isDarkThemeEnabledForTests
}
#endif
// Don't cache this value until it reflects the data store.
guard AppReadinessObjcBridge.isAppReady else {
return isSystemDarkThemeEnabled()
}
// Always respect the system theme in extensions.
guard CurrentAppContext().isMainApp else {
return switch Self.shareExtensionInterfaceStyleOverride {
case .dark:
true
case .light:
false
case .unspecified:
isSystemDarkThemeEnabled()
@unknown default:
isSystemDarkThemeEnabled()
}
}
if let cachedIsDarkThemeEnabled {
return cachedIsDarkThemeEnabled
}
let isDarkThemeEnabled: Bool = {
switch getOrFetchCurrentMode() {
case .system: return isSystemDarkThemeEnabled()
case .dark: return true
case .light: return false
}
}()
cachedIsDarkThemeEnabled = isDarkThemeEnabled
return isDarkThemeEnabled
}
private func isSystemDarkThemeEnabled() -> Bool {
return UITraitCollection.current.userInterfaceStyle == .dark
}
private func getOrFetchCurrentMode() -> ThemeDataStore.Appearance {
if let cachedCurrentMode {
return cachedCurrentMode
}
guard AppReadinessObjcBridge.isAppReady else {
return defaultMode
}
var currentMode: ThemeDataStore.Appearance = .system
SSKEnvironment.shared.databaseStorageRef.read { tx in
currentMode = self.themeDataStore.getCurrentMode(tx: tx)
}
cachedCurrentMode = currentMode
return currentMode
}
public func setCurrentMode(_ mode: ThemeDataStore.Appearance) {
AssertIsOnMainThread()
let previousMode = cachedCurrentMode
switch mode {
case .light:
cachedIsDarkThemeEnabled = false
case .dark:
cachedIsDarkThemeEnabled = true
case .system:
cachedIsDarkThemeEnabled = isSystemDarkThemeEnabled()
}
cachedCurrentMode = mode
// It's safe to do an async write because all accesses check self.cachedCurrentThemeNumber first.
SSKEnvironment.shared.databaseStorageRef.asyncWrite { tx in
self.themeDataStore.setCurrentMode(mode, tx: tx)
}
if previousMode != mode {
themeDidChange()
}
}
private var defaultMode: ThemeDataStore.Appearance {
return .system
}
private func notifyIfThemeModeIsNotDefault() {
if isDarkThemeEnabled || defaultMode != getOrFetchCurrentMode() {
themeDidChange()
}
}
// MARK: -
class func systemThemeChanged() {
shared.systemThemeChanged()
}
private func systemThemeChanged() {
// Do nothing, since we haven't setup the theme yet.
guard cachedIsDarkThemeEnabled != nil else { return }
// Theme can only be changed externally when in system mode.
guard getOrFetchCurrentMode() == .system else { return }
// We may get multiple updates for the same change.
let isSystemDarkThemeEnabled = isSystemDarkThemeEnabled()
guard cachedIsDarkThemeEnabled != isSystemDarkThemeEnabled else { return }
cachedIsDarkThemeEnabled = isSystemDarkThemeEnabled
themeDidChange()
}
private func themeDidChange() {
Theme.setupSignalAppearance()
NotificationCenter.default.post(name: .themeDidChange, object: self)
}
// MARK: - UI Colors
private static var currentThemeTraitCollection: UITraitCollection {
isDarkThemeEnabled ? darkTraitCollection : lightTraitCollection
}
private static var lightTraitCollection: UITraitCollection {
UITraitCollection(userInterfaceStyle: .light)
}
private static var darkTraitCollection: UITraitCollection {
UITraitCollection(userInterfaceStyle: .dark)
}
private static var elevatedLightTraitCollection: UITraitCollection {
UITraitCollection(traitsFrom: [
lightTraitCollection,
UITraitCollection(userInterfaceLevel: .elevated),
])
}
private static var elevatedDarkTraitCollection: UITraitCollection {
UITraitCollection(traitsFrom: [
darkTraitCollection,
UITraitCollection(userInterfaceLevel: .elevated),
])
}
public class var backgroundColor: UIColor {
isDarkThemeEnabled
? darkThemeBackgroundColor
: lightThemeBackgroundColor
}
public class var secondaryBackgroundColor: UIColor {
UIColor.Signal.secondaryBackground.resolvedColor(
with: isDarkThemeEnabled ? darkTraitCollection : lightTraitCollection,
)
}
public static var actionSheetBackgroundColor: UIColor {
isDarkThemeEnabled ? .ows_gray75 : .ows_white
}
public class var washColor: UIColor {
isDarkThemeEnabled ? darkThemeWashColor : .ows_gray05
}
public class var primaryTextColor: UIColor {
isDarkThemeEnabled ? darkThemePrimaryColor : lightThemePrimaryColor
}
public class var primaryIconColor: UIColor {
if #available(iOS 26, *) {
return primaryTextColor
}
return isDarkThemeEnabled ? darkThemeLegacyPrimaryIconColor : lightThemeLegacyPrimaryIconColor
}
public class var secondaryTextAndIconColor: UIColor {
isDarkThemeEnabled ? darkThemeSecondaryTextAndIconColor : lightThemeSecondaryTextAndIconColor
}
public class var navbarBackgroundColor: UIColor {
backgroundColor
}
public class var toolbarBackgroundColor: UIColor { navbarBackgroundColor }
// For accessibility:
//
// * Flat areas (e.g. button backgrounds) should use UIColor.ows_accentBlue.
// * Fine detail (e.g., text, non-filled icons) should use Theme.accentBlueColor.
// It is brighter in dark mode, improving legibility.
public class var accentBlueColor: UIColor {
UIColor.Signal.accent.resolvedColor(with: currentThemeTraitCollection)
}
public class var launchScreenBackgroundColor: UIColor {
backgroundColor
}
// MARK: - Table View
public class var tableCell2BackgroundColor: UIColor {
isDarkThemeEnabled
? darkThemeTableCell2BackgroundColor
: UIColor.Signal.secondaryGroupedBackground.resolvedColor(with: lightTraitCollection)
}
public class var tableCell2PresentedBackgroundColor: UIColor {
isDarkThemeEnabled
? darkThemeTableCell2PresentedBackgroundColor
: UIColor.Signal.secondaryGroupedBackground.resolvedColor(with: elevatedLightTraitCollection)
}
public class var tableCell2SelectedBackgroundColor: UIColor {
UIColor(
light: UIColor(rgbHex: 0xD4D4D6),
lightHighContrast: UIColor(rgbHex: 0xC6C6CA),
dark: UIColor(rgbHex: 0x3A3A3D),
darkHighContrast: UIColor(rgbHex: 0x525257),
)
}
public class var tableView2BackgroundColor: UIColor {
isDarkThemeEnabled
? darkThemeTableView2BackgroundColor
: UIColor.Signal.groupedBackground.resolvedColor(with: lightTraitCollection)
}
public class var tableView2PresentedBackgroundColor: UIColor {
isDarkThemeEnabled
? darkThemeTableView2PresentedBackgroundColor
: UIColor.Signal.groupedBackground.resolvedColor(with: elevatedLightTraitCollection)
}
public class var tableView2SeparatorColor: UIColor {
isDarkThemeEnabled ? darkThemeTableView2SeparatorColor : .ows_gray20
}
public class var tableView2PresentedSeparatorColor: UIColor {
isDarkThemeEnabled ? darkThemeTableView2PresentedSeparatorColor : .ows_gray20
}
// MARK: - Light Theme Colors
public class var lightThemeBackgroundColor: UIColor {
UIColor.Signal.background.resolvedColor(with: lightTraitCollection)
}
public class var lightThemePrimaryColor: UIColor {
UIColor.Signal.label.resolvedColor(with: lightTraitCollection)
}
public class var lightThemeLegacyPrimaryIconColor: UIColor { .ows_gray75 }
public class var lightThemeSecondaryTextAndIconColor: UIColor {
UIColor.Signal.secondaryLabel.resolvedColor(with: lightTraitCollection)
}
// MARK: - Dark Theme Colors
public class var darkThemeBackgroundColor: UIColor {
UIColor.Signal.background.resolvedColor(with: darkTraitCollection)
}
public class var darkThemePrimaryColor: UIColor {
UIColor.Signal.label.resolvedColor(with: darkTraitCollection)
}
public class var darkThemeLegacyPrimaryIconColor: UIColor { .ows_gray15 }
public class var darkThemeSecondaryTextAndIconColor: UIColor {
UIColor.Signal.secondaryLabel.resolvedColor(with: darkTraitCollection)
}
public class var darkThemeWashColor: UIColor { .ows_gray75 }
public class var darkThemeNavbarBackgroundColor: UIColor {
darkThemeBackgroundColor
}
public class var darkThemeNavbarIconColor: UIColor { .ows_gray15 }
public class var darkThemeTableCell2BackgroundColor: UIColor {
UIColor.Signal.secondaryGroupedBackground.resolvedColor(with: darkTraitCollection)
}
public class var darkThemeTableCell2PresentedBackgroundColor: UIColor {
UIColor.Signal.secondaryGroupedBackground.resolvedColor(with: elevatedDarkTraitCollection)
}
public class var darkThemeTableView2BackgroundColor: UIColor {
UIColor.Signal.groupedBackground.resolvedColor(with: darkTraitCollection)
}
public class var darkThemeTableView2PresentedBackgroundColor: UIColor {
UIColor.Signal.groupedBackground.resolvedColor(with: elevatedDarkTraitCollection)
}
public class var darkThemeTableView2SeparatorColor: UIColor { .ows_gray75 }
public class var darkThemeTableView2PresentedSeparatorColor: UIColor { .ows_gray65 }
// MARK: - Blur Effect
public class var barBlurEffect: UIBlurEffect {
isDarkThemeEnabled ? darkThemeBarBlurEffect : UIBlurEffect(style: .light)
}
public class var darkThemeBarBlurEffect: UIBlurEffect { UIBlurEffect(style: .dark) }
// MARK: - Keyboard
public class var keyboardAppearance: UIKeyboardAppearance {
isDarkThemeEnabled ? darkThemeKeyboardAppearance : .default
}
public class var darkThemeKeyboardAppearance: UIKeyboardAppearance { .dark }
public class var keyboardBackgroundColor: UIColor {
isDarkThemeEnabled ? .ows_gray90 : .ows_gray02
}
// MARK: - Search Bar
public class var barStyle: UIBarStyle {
isDarkThemeEnabled ? .black : .default
}
#if TESTABLE_BUILD
private var isDarkThemeEnabledForTests: Bool?
public class func setIsDarkThemeEnabledForTests(_ enabled: Bool) {
shared.isDarkThemeEnabledForTests = enabled
}
#endif
}
