✨ feat: add safe area insets handling for toast notifications

Author: shp7724

SNUTT/Modules/Shared/SharedUIComponents/Sources/AnimatableTabView/AnimatableTabView.swift

@@ -218,7 +218,9 @@ public struct TabScene<T: TabItem> {
 
     public init<Content>(tabItem: T, rootView: Content) where Content: View {
         self.tabItem = tabItem
-        self.rootView = AnyView(rootView)
+        self.rootView = AnyView(GeometryReader(content: { reader in
+            rootView.reportBottomSafeArea(reader.safeAreaInsets.bottom)
+        }))
     }
 
     public init(tabItem: T) {

SNUTT/Modules/Shared/SharedUIComponents/Sources/SafeAreaInsetsPreferenceKey.swift

@@ -0,0 +1,17 @@
+import SwiftUI
+
+/// Preference key for communicating safe area insets (including TabView height) from child views
+struct SafeAreaBottomInsetsPreferenceKey: PreferenceKey {
+    static let defaultValue: CGFloat = 0
+
+    static func reduce(value: inout CGFloat, nextValue: () -> CGFloat) {
+        value = max(value, nextValue())
+    }
+}
+
+extension View {
+    /// Reports the bottom safe area inset (including TabView height) to ancestor views
+    func reportBottomSafeArea(_ inset: CGFloat) -> some View {
+        preference(key: SafeAreaBottomInsetsPreferenceKey.self, value: inset)
+    }
+}

SNUTT/Modules/Shared/SharedUIComponents/Sources/Toast/Toast+Modifier.swift

@@ -36,6 +36,7 @@ extension View {
 
 private struct ToastContainerModifier<Content: View>: View {
     @State private var viewModel = ToastContainerViewModel()
+    @State private var bottomSafeArea: CGFloat = 0
     let content: Content
 
     init(content: Content) {
@@ -50,18 +51,27 @@ private struct ToastContainerModifier<Content: View>: View {
                     viewModel.present(toast)
                 }
             )
-            .overlay(alignment: .bottom) {
-                VStack(spacing: 8) {
-                    ForEach(viewModel.toasts) { toast in
-                        ToastItemView(toast: toast) {
-                            viewModel.handleButtonTap(for: toast)
+            .onPreferenceChange(SafeAreaBottomInsetsPreferenceKey.self) { value in
+                bottomSafeArea = value
+            }
+            .overlay(alignment: .bottom,) {
+                GeometryReader { reader in
+                    /// The view inside `.overlay` already respects the safe area.
+                    /// Subtracting the default safe area inset gives us the extra bottom inset (for example, from tab bars).
+                    let additionalSafeAreaInsetBottom = bottomSafeArea - reader.safeAreaInsets.bottom
+                    VStack(spacing: 8) {
+                        ForEach(viewModel.toasts) { toast in
+                            ToastItemView(toast: toast) {
+                                viewModel.handleButtonTap(for: toast)
+                            }
+                            .transition(.move(edge: .bottom).combined(with: .blurReplace))
                         }
-                        .transition(.move(edge: .bottom).combined(with: .blurReplace))
                     }
+                    .padding(.horizontal, 20)
+                    .padding(.bottom, additionalSafeAreaInsetBottom + 8)
+                    .animation(.defaultSpring, value: viewModel.toasts)
+                    .frame(maxWidth: .infinity, maxHeight: .infinity, alignment: .bottom)
                 }
-                .padding(.horizontal, 20)
-                .padding(.bottom, 16)
-                .animation(.defaultSpring, value: viewModel.toasts)
             }
     }
 }

SNUTT/Modules/Shared/SharedUIComponents/Sources/Toast/ToastContainer.swift

@@ -4,10 +4,19 @@ import SwiftUIUtility
 @MainActor
 @Observable
 final class ToastContainerViewModel {
+    private enum Constants {
+        static let maxVisibleToasts = 3
+    }
+
     private(set) var toasts: [Toast] = []
     private var dismissTasks: [UUID: Task<Void, Never>] = [:]
 
     func present(_ toast: Toast) {
+        // Dismiss oldest toast if we've reached the maximum
+        if toasts.count >= Constants.maxVisibleToasts, let oldestToast = toasts.first {
+            dismiss(oldestToast)
+        }
+
         toasts.append(toast)
 
         let dismissTask = Task { @MainActor in