Initial commit: suixinkan_ios UIKit rewrite project.

Co-authored-by: Cursor <cursoragent@cursor.com>

suixinkan_ios/App/State/ToastCenter.swift

@@ -0,0 +1,182 @@
+//
+//  ToastCenter.swift
+//  suixinkan
+//
+//  Created by Codex on 2026/6/18.
+//
+
+import UIKit
+
+@MainActor
+/// 全局 Toast 状态中心，负责保存和清除当前提示文案。
+final class ToastCenter {
+    var onChange: (() -> Void)?
+    private(set) var message: String? { didSet { onChange?() } }
+
+    private let autoDismissNanoseconds: UInt64
+    private var dismissTask: Task<Void, Never>?
+    private var displayToken: UInt64 = 0
+    private weak var overlayView: ToastOverlayView?
+
+    /// 创建 Toast 状态中心，默认 2.2 秒后自动隐藏。
+    init(autoDismissNanoseconds: UInt64 = 2_200_000_000) {
+        self.autoDismissNanoseconds = autoDismissNanoseconds
+    }
+
+    /// 显示一条全局 Toast 文案。
+    func show(_ message: String) {
+        displayToken &+= 1
+        self.message = message
+        scheduleAutoDismiss(token: displayToken)
+    }
+
+    /// 清除当前 Toast 文案。
+    func dismiss() {
+        displayToken &+= 1
+        dismissTask?.cancel()
+        dismissTask = nil
+        message = nil
+    }
+
+    /// 将全局 Toast 展示层挂载到指定窗口，通常只在应用根部调用一次。
+    func attachToWindow(_ window: UIWindow) {
+        if let overlayView, overlayView.superview === window {
+            return
+        }
+
+        let overlay = ToastOverlayView(center: self)
+        overlay.frame = window.bounds
+        overlay.autoresizingMask = [.flexibleWidth, .flexibleHeight]
+        window.addSubview(overlay)
+        overlayView = overlay
+    }
+
+    /// 为当前 Toast 安排自动隐藏任务，并避免旧任务误清除新 Toast。
+    private func scheduleAutoDismiss(token: UInt64) {
+        dismissTask?.cancel()
+        let delay = autoDismissNanoseconds
+        dismissTask = Task { [weak self] in
+            do {
+                try await Task.sleep(nanoseconds: delay)
+            } catch {
+                return
+            }
+            await MainActor.run {
+                guard let self, self.displayToken == token else { return }
+                self.message = nil
+                self.dismissTask = nil
+            }
+        }
+    }
+
+    #if DEBUG
+    /// 测试专用快照，业务代码不应读取 Toast 展示状态。
+    var snapshotForTests: ToastSnapshot {
+        ToastSnapshot(message: message)
+    }
+    #endif
+}
+
+#if DEBUG
+/// 全局 Toast 测试快照，用于验证文案和自动隐藏行为。
+struct ToastSnapshot: Equatable {
+    let message: String?
+}
+#endif
+
+/// 全局 Toast 展示层，负责把 Toast 展示到窗口顶部。
+final class ToastOverlayView: UIView {
+    private weak var toastCenter: ToastCenter?
+    private let bannerView = UIView()
+    private let messageLabel = UILabel()
+
+    /// 使用 Toast 状态中心初始化展示层。
+    init(center: ToastCenter) {
+        self.toastCenter = center
+        super.init(frame: .zero)
+        isUserInteractionEnabled = false
+        configureViews()
+        center.onChange = { [weak self] in
+            self?.refreshPresentation(animated: true)
+        }
+        refreshPresentation(animated: false)
+    }
+
+    required init?(coder: NSCoder) {
+        nil
+    }
+
+    private func configureViews() {
+        bannerView.backgroundColor = AppDesign.primary
+        bannerView.isHidden = true
+        bannerView.alpha = 0
+
+        messageLabel.font = .systemFont(ofSize: 14, weight: .medium)
+        messageLabel.textColor = .white
+        messageLabel.textAlignment = .center
+        messageLabel.numberOfLines = 2
+
+        bannerView.addSubview(messageLabel)
+        addSubview(bannerView)
+
+        bannerView.translatesAutoresizingMaskIntoConstraints = false
+        messageLabel.translatesAutoresizingMaskIntoConstraints = false
+
+        NSLayoutConstraint.activate([
+            bannerView.leadingAnchor.constraint(equalTo: leadingAnchor),
+            bannerView.trailingAnchor.constraint(equalTo: trailingAnchor),
+            bannerView.topAnchor.constraint(equalTo: topAnchor),
+
+            messageLabel.leadingAnchor.constraint(equalTo: bannerView.leadingAnchor, constant: AppMetrics.Spacing.pageHorizontal),
+            messageLabel.trailingAnchor.constraint(equalTo: bannerView.trailingAnchor, constant: -AppMetrics.Spacing.pageHorizontal),
+            messageLabel.topAnchor.constraint(equalTo: bannerView.safeAreaLayoutGuide.topAnchor, constant: AppMetrics.Spacing.small),
+            messageLabel.bottomAnchor.constraint(equalTo: bannerView.bottomAnchor, constant: -AppMetrics.Spacing.small)
+        ])
+    }
+
+    private func refreshPresentation(animated: Bool) {
+        guard let message = toastCenter?.message, !message.isEmpty else {
+            hideBanner(animated: animated)
+            return
+        }
+
+        messageLabel.text = message
+        showBanner(animated: animated)
+    }
+
+    private func showBanner(animated: Bool) {
+        guard bannerView.isHidden || bannerView.alpha < 1 else { return }
+
+        bannerView.isHidden = false
+        guard animated else {
+            bannerView.alpha = 1
+            bannerView.transform = .identity
+            return
+        }
+
+        bannerView.alpha = 0
+        bannerView.transform = CGAffineTransform(translationX: 0, y: -12)
+        UIView.animate(withDuration: 0.18, delay: 0, options: [.curveEaseInOut]) {
+            self.bannerView.alpha = 1
+            self.bannerView.transform = .identity
+        }
+    }
+
+    private func hideBanner(animated: Bool) {
+        guard !bannerView.isHidden else { return }
+
+        guard animated else {
+            bannerView.isHidden = true
+            bannerView.alpha = 0
+            return
+        }
+
+        UIView.animate(withDuration: 0.18, delay: 0, options: [.curveEaseInOut], animations: {
+            self.bannerView.alpha = 0
+            self.bannerView.transform = CGAffineTransform(translationX: 0, y: -12)
+        }, completion: { _ in
+            self.bannerView.isHidden = true
+            self.bannerView.transform = .identity
+        })
+    }
+}