SwiftUI GeometryReader for dynamic layouts

import SwiftUI

struct ResponsiveGridView: View {
    let items: [GridItem]

    var body: some View {
        GeometryReader { geometry in
            let columns = calculateColumns(for: geometry.size.width)
            let spacing: CGFloat = 16
            let itemWidth = (geometry.size.width - spacing * CGFloat(columns + 1)) / CGFloat(columns)

            ScrollView {
                LazyVStack(spacing: spacing) {
                    ForEach(items.chunked(into: columns), id: \.self) { row in
                        HStack(spacing: spacing) {
                            ForEach(row) { item in
                                GridItemView(item: item)
                                    .frame(width: itemWidth, height: itemWidth)
                            }

                            // Fill remaining space if row is incomplete
                            if row.count < columns {
                                ForEach(0..<(columns - row.count), id: \.self) { _ in
                                    Color.clear
                                        .frame(width: itemWidth, height: itemWidth)
                                }
                            }
                        }
                    }
                }
                .padding(spacing)
            }
        }
    }

    private func calculateColumns(for width: CGFloat) -> Int {
        switch width {
        case 0..<400:
            return 2
        case 400..<600:
            return 3
        case 600..<900:
            return 4
        default:
            return 5
        }
    }
}

struct ParallaxHeaderView: View {
    let title: String
    let imageURL: URL

    var body: some View {
        ScrollView {
            GeometryReader { geometry in
                let offset = geometry.frame(in: .global).minY
                let height = max(200, 200 + offset)
                let opacity = max(0, min(1, 1 - offset / 200))

                AsyncImage(url: imageURL) { image in
                    image
                        .resizable()
                        .aspectRatio(contentMode: .fill)
                        .frame(width: geometry.size.width, height: height)
                        .clipped()
                        .offset(y: offset > 0 ? -offset : 0)
                } placeholder: {
                    Rectangle()
                        .fill(Color.gray)
                        .frame(height: height)
                }
                .overlay(
                    LinearGradient(
                        colors: [.clear, .black.opacity(0.7)],
                        startPoint: .top,
                        endPoint: .bottom
                    )
                )
                .overlay(
                    Text(title)
                        .font(.largeTitle)
                        .fontWeight(.bold)
                        .foregroundColor(.white)
                        .opacity(opacity)
                        .padding()
                    , alignment: .bottomLeading
                )
            }
            .frame(height: 200)

            // Content below header
            VStack(alignment: .leading, spacing: 20) {
                Text("Content")
                    .font(.title2)

                ForEach(0..<20) { index in
                    Text("Item \(index)")
                        .padding()
                        .frame(maxWidth: .infinity)
                        .background(Color.gray.opacity(0.1))
                        .cornerRadius(10)
                }
            }
            .padding()
        }
        .edgesIgnoringSafeArea(.top)
    }
}

struct CircularLayout: View {
    let items: [String]

    var body: some View {
        GeometryReader { geometry in
            let center = CGPoint(
                x: geometry.size.width / 2,
                y: geometry.size.height / 2
            )
            let radius = min(geometry.size.width, geometry.size.height) / 2.5

            ZStack {
                ForEach(Array(items.enumerated()), id: \.offset) { index, item in
                    let angle = (2 * .pi / Double(items.count)) * Double(index) - .pi / 2
                    let x = center.x + radius * cos(angle)
                    let y = center.y + radius * sin(angle)

                    Text(item)
                        .font(.headline)
                        .padding()
                        .background(Color.blue)
                        .foregroundColor(.white)
                        .cornerRadius(10)
                        .position(x: x, y: y)
                }
            }
        }
    }
}