Appearance based on system theme

Session/Meta/AppDelegate.m

@@ -194,8 +194,8 @@ static NSTimeInterval launchStartedAt;
     mainWindow.rootViewController = [LoadingViewController new];
     [mainWindow makeKeyAndVisible];
 
-    LKAppMode appMode = [self getAppModeOrSystemDefault];
+    LKAppMode appMode = [self getCurrentAppMode];
-    [self setCurrentAppMode:appMode];
+    [self adaptAppMode:appMode];
 
     if (@available(iOS 11, *)) {
         // This must happen in appDidFinishLaunching or earlier to ensure we don't
@@ -246,7 +246,7 @@ static NSTimeInterval launchStartedAt;
     [self ensureRootViewController];
 
     LKAppMode appMode = [self getCurrentAppMode];
-    [self setCurrentAppMode:appMode];
+    [self adaptAppMode:appMode];
 
     [AppReadiness runNowOrWhenAppDidBecomeReady:^{
         [self handleActivation];
@@ -709,16 +709,10 @@ static NSTimeInterval launchStartedAt;
 
 # pragma mark - App Mode
 
-- (LKAppMode)getCurrentAppMode
+- (void)adaptAppMode:(LKAppMode)appMode
-{
-    return [NSUserDefaults.standardUserDefaults integerForKey:@"appMode"];
-}
-
-- (void)setCurrentAppMode:(LKAppMode)appMode
 {
     UIWindow *window = UIApplication.sharedApplication.keyWindow;
     if (window == nil) { return; }
-    [NSUserDefaults.standardUserDefaults setInteger:appMode forKey:@"appMode"];
     switch (appMode) {
         case LKAppModeLight: {
             if (@available(iOS 13.0, *)) {
@@ -735,9 +729,34 @@ static NSTimeInterval launchStartedAt;
             break;
         }
     }
+    if (LKAppModeUtilities.isSystemDefault) {
+        if (@available(iOS 13.0, *)) {
+            window.overrideUserInterfaceStyle = UIUserInterfaceStyleUnspecified;
+        }
+    }
     [NSNotificationCenter.defaultCenter postNotificationName:NSNotification.appModeChanged object:nil];
 }
 
+- (LKAppMode)getCurrentAppMode
+{
+    LKAppMode appMode = [self getAppModeOrSystemDefault];
+    UIWindow *window = UIApplication.sharedApplication.keyWindow;
+    return appMode;
+}
+
+- (void)setCurrentAppMode:(LKAppMode)appMode
+{
+    [NSUserDefaults.standardUserDefaults setInteger:appMode forKey:@"appMode"];
+    [self adaptAppMode:appMode];
+}
+
+- (void)setAppModeToSystemDefault
+{
+    [NSUserDefaults.standardUserDefaults removeObjectForKey:@"appMode"];
+    LKAppMode appMode = [self getCurrentAppMode];
+    [self adaptAppMode:appMode];
+}
+
 # pragma mark - Other
 
 - (void)handleDataNukeRequested:(NSNotification *)notification

Session/Meta/Images.xcassets/ic_dark_theme_off.imageset/Contents.json

@@ -1,23 +1,12 @@
 {
   "images" : [
     {
-      "idiom" : "universal",
+      "filename" : "moon.pdf",
-      "filename" : "dark-theme-off-24@1x.png",
+      "idiom" : "universal"
-      "scale" : "1x"
-    },
-    {
-      "idiom" : "universal",
-      "filename" : "dark-theme-off-24@2x.png",
-      "scale" : "2x"
-    },
-    {
-      "idiom" : "universal",
-      "filename" : "dark-theme-off-24@3x.png",
-      "scale" : "3x"
     }
   ],
   "info" : {
-    "version" : 1,
+    "author" : "xcode",
-    "author" : "xcode"
+    "version" : 1
   }
-}
+}

Session/Meta/Images.xcassets/ic_dark_theme_on.imageset/Contents.json

@@ -1,23 +1,12 @@
 {
   "images" : [
     {
-      "idiom" : "universal",
+      "filename" : "moon_fill.pdf",
-      "filename" : "dark-theme-on-24@1x.png",
+      "idiom" : "universal"
-      "scale" : "1x"
-    },
-    {
-      "idiom" : "universal",
-      "filename" : "dark-theme-on-24@2x.png",
-      "scale" : "2x"
-    },
-    {
-      "idiom" : "universal",
-      "filename" : "dark-theme-on-24@3x.png",
-      "scale" : "3x"
     }
   ],
   "info" : {
-    "version" : 1,
+    "author" : "xcode",
-    "author" : "xcode"
+    "version" : 1
   }
-}
+}

Session/Meta/Images.xcassets/ic_theme_auto.imageset/Contents.json

@@ -0,0 +1,12 @@
+{
+  "images" : [
+    {
+      "filename" : "moon_auto.pdf",
+      "idiom" : "universal"
+    }
+  ],
+  "info" : {
+    "author" : "xcode",
+    "version" : 1
+  }
+}

Session/Meta/Translations/de.lproj/Localizable.strings

@@ -572,3 +572,6 @@
 /* Button text which opens the settings app */
 "OPEN_SETTINGS_BUTTON" = "Settings";
 "APN_Message" = "You've got a new message";
+"system_mode_theme" = "System";
+"dark_mode_theme" = "Dark";
+"light_mode_theme" = "Light";

Session/Meta/Translations/en.lproj/Localizable.strings

@@ -573,3 +573,6 @@
 /* Button text which opens the settings app */
 "OPEN_SETTINGS_BUTTON" = "Settings";
 "APN_Message" = "You've got a new message";
+"system_mode_theme" = "System";
+"dark_mode_theme" = "Dark";
+"light_mode_theme" = "Light";

Session/Meta/Translations/es.lproj/Localizable.strings

@@ -572,3 +572,6 @@
 /* Button text which opens the settings app */
 "OPEN_SETTINGS_BUTTON" = "Settings";
 "APN_Message" = "You've got a new message";
+"system_mode_theme" = "System";
+"dark_mode_theme" = "Dark";
+"light_mode_theme" = "Light";

Session/Meta/Translations/fa.lproj/Localizable.strings

@@ -572,3 +572,6 @@
 /* Button text which opens the settings app */
 "OPEN_SETTINGS_BUTTON" = "Settings";
 "APN_Message" = "You've got a new message";
+"system_mode_theme" = "System";
+"dark_mode_theme" = "Dark";
+"light_mode_theme" = "Light";

Session/Meta/Translations/fi.lproj/Localizable.strings

@@ -572,3 +572,6 @@
 /* Button text which opens the settings app */
 "OPEN_SETTINGS_BUTTON" = "Settings";
 "APN_Message" = "You've got a new message";
+"system_mode_theme" = "System";
+"dark_mode_theme" = "Dark";
+"light_mode_theme" = "Light";

Session/Meta/Translations/fr.lproj/Localizable.strings

@@ -572,3 +572,6 @@
 /* Button text which opens the settings app */
 "OPEN_SETTINGS_BUTTON" = "Settings";
 "APN_Message" = "You've got a new message";
+"system_mode_theme" = "System";
+"dark_mode_theme" = "Dark";
+"light_mode_theme" = "Light";

Session/Meta/Translations/hi.lproj/Localizable.strings

@@ -572,3 +572,6 @@
 /* Button text which opens the settings app */
 "OPEN_SETTINGS_BUTTON" = "Settings";
 "APN_Message" = "You've got a new message";
+"system_mode_theme" = "System";
+"dark_mode_theme" = "Dark";
+"light_mode_theme" = "Light";

Session/Meta/Translations/hr.lproj/Localizable.strings

@@ -572,3 +572,6 @@
 /* Button text which opens the settings app */
 "OPEN_SETTINGS_BUTTON" = "Settings";
 "APN_Message" = "You've got a new message";
+"system_mode_theme" = "System";
+"dark_mode_theme" = "Dark";
+"light_mode_theme" = "Light";

Session/Meta/Translations/id-ID.lproj/Localizable.strings

@@ -572,3 +572,6 @@
 /* Button text which opens the settings app */
 "OPEN_SETTINGS_BUTTON" = "Settings";
 "APN_Message" = "You've got a new message";
+"system_mode_theme" = "System";
+"dark_mode_theme" = "Dark";
+"light_mode_theme" = "Light";

Session/Meta/Translations/it.lproj/Localizable.strings

@@ -572,3 +572,6 @@
 /* Button text which opens the settings app */
 "OPEN_SETTINGS_BUTTON" = "Settings";
 "APN_Message" = "You've got a new message";
+"system_mode_theme" = "System";
+"dark_mode_theme" = "Dark";
+"light_mode_theme" = "Light";

Session/Meta/Translations/ja.lproj/Localizable.strings

@@ -572,3 +572,6 @@
 /* Button text which opens the settings app */
 "OPEN_SETTINGS_BUTTON" = "Settings";
 "APN_Message" = "You've got a new message";
+"system_mode_theme" = "System";
+"dark_mode_theme" = "Dark";
+"light_mode_theme" = "Light";

Session/Meta/Translations/nl.lproj/Localizable.strings

@@ -572,3 +572,6 @@
 /* Button text which opens the settings app */
 "OPEN_SETTINGS_BUTTON" = "Settings";
 "APN_Message" = "You've got a new message";
+"system_mode_theme" = "System";
+"dark_mode_theme" = "Dark";
+"light_mode_theme" = "Light";

Session/Meta/Translations/pl.lproj/Localizable.strings

@@ -572,3 +572,6 @@
 /* Button text which opens the settings app */
 "OPEN_SETTINGS_BUTTON" = "Settings";
 "APN_Message" = "You've got a new message";
+"system_mode_theme" = "System";
+"dark_mode_theme" = "Dark";
+"light_mode_theme" = "Light";

Session/Meta/Translations/pt_BR.lproj/Localizable.strings

@@ -572,3 +572,6 @@
 /* Button text which opens the settings app */
 "OPEN_SETTINGS_BUTTON" = "Settings";
 "APN_Message" = "You've got a new message";
+"system_mode_theme" = "System";
+"dark_mode_theme" = "Dark";
+"light_mode_theme" = "Light";

Session/Meta/Translations/ru.lproj/Localizable.strings

@@ -572,3 +572,6 @@
 /* Button text which opens the settings app */
 "OPEN_SETTINGS_BUTTON" = "Settings";
 "APN_Message" = "You've got a new message";
+"system_mode_theme" = "System";
+"dark_mode_theme" = "Dark";
+"light_mode_theme" = "Light";

Session/Meta/Translations/si.lproj/Localizable.strings

@@ -573,3 +573,6 @@
 /* Button text which opens the settings app */
 "OPEN_SETTINGS_BUTTON" = "Settings";
 "APN_Message" = "You've got a new message";
+"system_mode_theme" = "System";
+"dark_mode_theme" = "Dark";
+"light_mode_theme" = "Light";

Session/Meta/Translations/sk.lproj/Localizable.strings

@@ -572,3 +572,6 @@
 /* Button text which opens the settings app */
 "OPEN_SETTINGS_BUTTON" = "Settings";
 "APN_Message" = "You've got a new message";
+"system_mode_theme" = "System";
+"dark_mode_theme" = "Dark";
+"light_mode_theme" = "Light";

Session/Meta/Translations/sv.lproj/Localizable.strings

@@ -572,3 +572,6 @@
 /* Button text which opens the settings app */
 "OPEN_SETTINGS_BUTTON" = "Settings";
 "APN_Message" = "You've got a new message";
+"system_mode_theme" = "System";
+"dark_mode_theme" = "Dark";
+"light_mode_theme" = "Light";

Session/Meta/Translations/th.lproj/Localizable.strings

@@ -572,3 +572,6 @@
 /* Button text which opens the settings app */
 "OPEN_SETTINGS_BUTTON" = "Settings";
 "APN_Message" = "You've got a new message";
+"system_mode_theme" = "System";
+"dark_mode_theme" = "Dark";
+"light_mode_theme" = "Light";

Session/Meta/Translations/vi-VN.lproj/Localizable.strings

@@ -572,3 +572,6 @@
 /* Button text which opens the settings app */
 "OPEN_SETTINGS_BUTTON" = "Settings";
 "APN_Message" = "You've got a new message";
+"system_mode_theme" = "System";
+"dark_mode_theme" = "Dark";
+"light_mode_theme" = "Light";

Session/Meta/Translations/zh-Hant.lproj/Localizable.strings

@@ -572,3 +572,6 @@
 /* Button text which opens the settings app */
 "OPEN_SETTINGS_BUTTON" = "Settings";
 "APN_Message" = "You've got a new message";
+"system_mode_theme" = "System";
+"dark_mode_theme" = "Dark";
+"light_mode_theme" = "Light";

Session/Meta/Translations/zh_CN.lproj/Localizable.strings

@@ -572,3 +572,6 @@
 /* Button text which opens the settings app */
 "OPEN_SETTINGS_BUTTON" = "Settings";
 "APN_Message" = "You've got a new message";
+"system_mode_theme" = "System";
+"dark_mode_theme" = "Dark";
+"light_mode_theme" = "Light";

Session/Settings/SettingsVC.swift

@@ -303,7 +303,12 @@ final class SettingsVC : BaseVC, AvatarViewHelperDelegate {
             closeButton.isAccessibilityElement = true
             navigationItem.leftBarButtonItem = closeButton
             if #available(iOS 13, *) { // Pre iOS 13 the user can't switch actively but the app still responds to system changes
-                let appModeIcon = isDarkMode ? #imageLiteral(resourceName: "ic_dark_theme_on").withTintColor(.white) : #imageLiteral(resourceName: "ic_dark_theme_off").withTintColor(.black)
+                let appModeIcon: UIImage
+                if isSystemDefault {
+                    appModeIcon = isDarkMode ? #imageLiteral(resourceName: "ic_theme_auto").withTintColor(.white) : #imageLiteral(resourceName: "ic_theme_auto").withTintColor(.black)
+                } else {
+                    appModeIcon = isDarkMode ? #imageLiteral(resourceName: "ic_dark_theme_on").withTintColor(.white) : #imageLiteral(resourceName: "ic_dark_theme_off").withTintColor(.black)
+                }
                 let appModeButton = UIButton()
                 appModeButton.setImage(appModeIcon, for: UIControl.State.normal)
                 appModeButton.tintColor = Colors.text
@@ -404,8 +409,26 @@ final class SettingsVC : BaseVC, AvatarViewHelperDelegate {
     }
 
     @objc private func switchAppMode() {
-        let newAppMode: AppMode = isLightMode ? .dark : .light
+        let alertVC = UIAlertController.init(title: nil, message: nil, preferredStyle: .actionSheet)
-        AppModeManager.shared.setCurrentAppMode(to: newAppMode)
+        let systemModeAction = UIAlertAction.init(title: NSLocalizedString("system_mode_theme", comment: ""), style: .default) { _ in
+            AppModeManager.shared.setAppModeToSystemDefault()
+        }
+        alertVC.addAction(systemModeAction)
+        
+        let darkModeAction = UIAlertAction.init(title: NSLocalizedString("dark_mode_theme", comment: ""), style: .default) { _ in
+            AppModeManager.shared.setCurrentAppMode(to: .dark)
+        }
+        alertVC.addAction(darkModeAction)
+        
+        let lightModeAction = UIAlertAction.init(title: NSLocalizedString("light_mode_theme", comment: ""), style: .default) { _ in
+            AppModeManager.shared.setCurrentAppMode(to: .light)
+        }
+        alertVC.addAction(lightModeAction)
+        
+        let cancelAction = UIAlertAction.init(title: NSLocalizedString("TXT_CANCEL_TITLE", comment: ""), style: .cancel) {_ in }
+        alertVC.addAction(cancelAction)
+        
+        self.presentAlert(alertVC)
     }
 
     @objc private func showQRCode() {

Session/Shared/BaseVC.swift

@@ -26,6 +26,16 @@ class BaseVC : UIViewController {
         setNeedsStatusBarAppearanceUpdate()
         NotificationCenter.default.addObserver(self, selector: #selector(handleAppModeChangedNotification(_:)), name: .appModeChanged, object: nil)
     }
+    
+    internal func ensureWindowBackground() {
+        let appMode = AppModeManager.shared.currentAppMode
+        switch appMode {
+        case .light:
+            UIApplication.shared.delegate?.window??.backgroundColor = .white
+        case .dark:
+            UIApplication.shared.delegate?.window??.backgroundColor = .black
+        }
+    }
 
     internal func setUpGradientBackground() {
         hasGradient = true
@@ -80,12 +90,13 @@ class BaseVC : UIViewController {
     }
 
     override func traitCollectionDidChange(_ previousTraitCollection: UITraitCollection?) {
-        // TODO: Post an appModeChanged notification?
+        NotificationCenter.default.post(name: .appModeChanged, object: nil)
     }
 
     @objc internal func handleAppModeChangedNotification(_ notification: Notification) {
         if hasGradient {
             setUpGradientBackground() // Re-do the gradient
         }
+        ensureWindowBackground()
     }
 }

SessionShareExtension/ShareVC.swift

@@ -173,6 +173,10 @@ final class ShareVC : UINavigationController, ShareViewDelegate, AppModeManagerD
         return // Not applicable to share extensions
     }
     
+    public func setAppModeToSystemDefault() {
+        return // Not applicable to share extensions
+    }
+    
     // MARK: Updating
     private func showLockScreenOrMainContent() {
         if OWSScreenLock.shared.isScreenLockEnabled() {

SessionUIKit/Style Guide/AppMode.swift

@@ -25,6 +25,10 @@ public final class AppModeManager : NSObject {
     public func setCurrentAppMode(to appMode: AppMode) {
         delegate.setCurrentAppMode(to: appMode)
     }
+    
+    public func setAppModeToSystemDefault() {
+        delegate.setAppModeToSystemDefault()
+    }
 }
 
 @objc(LKAppModeManagerDelegate)
@@ -33,6 +37,7 @@ public protocol AppModeManagerDelegate {
     func getCurrentAppMode() -> AppMode
     @objc(setCurrentAppMode:)
     func setCurrentAppMode(to appMode: AppMode)
+    func setAppModeToSystemDefault()
 }
 
 @objc(LKAppMode)
@@ -40,6 +45,10 @@ public enum AppMode : Int {
     case light, dark
 }
 
+public var isSystemDefault: Bool {
+    return !UserDefaults.standard.dictionaryRepresentation().keys.contains("appMode")
+}
+
 public var isLightMode: Bool {
     return AppModeManager.shared.currentAppMode == .light
 }
@@ -49,6 +58,10 @@ public var isDarkMode: Bool {
 }
 
 @objc public final class LKAppModeUtilities : NSObject {
+    
+    @objc public static var isSystemDefault: Bool {
+        return !UserDefaults.standard.dictionaryRepresentation().keys.contains("appMode")
+    }
 
     @objc public static var isLightMode: Bool {
         return AppModeManager.shared.currentAppMode == .light