Yattee v2 rewrite

Yattee/Views/Components/DynamicSheet.swift

@@ -0,0 +1,71 @@
+//
+//  DynamicSheet.swift
+//  Yattee
+//
+//  Primitives for dynamic sheet height based on calculated content size.
+//  For List/Form content that doesn't have intrinsic size.
+//
+
+import SwiftUI
+
+// MARK: - Environment Key for Sheet Height
+
+private struct SheetHeightKey: EnvironmentKey {
+    static let defaultValue: Binding<CGFloat>? = nil
+}
+
+extension EnvironmentValues {
+    /// Binding to report calculated content height to the sheet container.
+    var sheetContentHeight: Binding<CGFloat>? {
+        get { self[SheetHeightKey.self] }
+        set { self[SheetHeightKey.self] = newValue }
+    }
+}
+
+// MARK: - Dynamic Sheet Container
+
+/// A sheet container that adjusts detents based on reported content height.
+/// Child views should write to `sheetContentHeight` environment to report their size.
+struct DynamicSheetContainer<Content: View>: View {
+    var animation: Animation = .smooth(duration: 0.35)
+    @ViewBuilder var content: Content
+
+    @State private var contentHeight: CGFloat = 0
+
+    var body: some View {
+        content
+            .environment(\.sheetContentHeight, Binding(
+                get: { contentHeight },
+                set: { newValue in
+                    if contentHeight == 0 {
+                        contentHeight = newValue
+                    } else {
+                        withAnimation(animation) {
+                            contentHeight = newValue
+                        }
+                    }
+                }
+            ))
+            #if os(iOS)
+            .modifier(SheetHeightModifier(height: contentHeight))
+            #endif
+    }
+}
+
+// MARK: - Animatable Sheet Height Modifier
+
+/// ViewModifier that applies presentation detents with smooth animation.
+/// Conforms to Animatable so SwiftUI can interpolate height changes.
+private struct SheetHeightModifier: ViewModifier, Animatable {
+    var height: CGFloat
+
+    var animatableData: CGFloat {
+        get { height }
+        set { height = newValue }
+    }
+
+    func body(content: Content) -> some View {
+        content
+            .presentationDetents(height == 0 ? [.medium, .large] : [.height(height), .large])
+    }
+}