[DVStack] First build of DVStack System

Sources/DefinedElements/Frameworks/App/iOS/DApp-iOS.Root.swift

@@ -0,0 +1,23 @@
+#if os(iOS)
+
+import Foundation
+import SwiftUI
+
+internal struct DefinedAppRoot<StartPage> : Scene where StartPage: DefinedPage {
+    var start: StartPage
+
+    init(from: StartPage) {
+        self.start = from
+    }
+
+    var body: some Scene {
+        WindowGroup {
+            EmptyView()
+                .onAppear(perform: {
+                    UIApplication.startApplication(from: self.start)
+                })
+        }
+    }
+}
+
+#endif

Sources/DefinedElements/Frameworks/App/iOS/StatusBar/DApp-iOS.StatusBar.swift

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+#if os(iOS)
+
+import Foundation
+import SwiftUI
+
+/// [DE Internal] A root view controller alternative to empower the ability of changing status bar style.
+internal class DefinedStatusBarController: UIHostingController<DefinedViewStack> {
+    /// The current status bar style holder.
+    var statusBarStyle: UIStatusBarStyle = .darkContent
+
+    override var preferredStatusBarStyle: UIStatusBarStyle {
+        return statusBarStyle
+    }
+
+    /// Change the style holder inside the controller by given style.
+    ///
+    /// - Parameter style: The target style.
+    func changeStatusBarStyle(_ style: UIStatusBarStyle) {
+        self.statusBarStyle = style
+        self.setNeedsStatusBarAppearanceUpdate()
+    }
+}
+
+internal extension UIApplication {
+    /// [DE Internal] Set the start page of the app and empower the ability of changing status bar style.
+    ///
+    /// - Parameter from: The root page (start page for the root view stack) of an app.
+    class func startApplication<StartPage>(from page: StartPage) where StartPage: DefinedPage {
+        UIApplication.shared.windows.first?.rootViewController?.beginAppearanceTransition(false, animated: false)
+        UIApplication.shared.windows.first?.rootViewController = DefinedStatusBarController(rootView: DefinedViewStack(from: page))
+    }
+
+    /// [DE Internal] Set the status bar style over the entire app.
+    ///
+    /// Handling the status bar style modification should be in `DefinedViewStack` system instead of here.
+    ///
+    /// - Parameter style: The target style.
+    class func setStatusBarStyle(_ style: UIStatusBarStyle) {
+        if let viewController = UIApplication.getKeyWindow()?.rootViewController as? DefinedStatusBarController {
+            viewController.changeStatusBarStyle(style)
+        }
+    }
+
+    private class func getKeyWindow() -> UIWindow? {
+        return UIApplication.shared.windows.first{ $0.isKeyWindow }
+    }
+}
+
+#endif