Slider

Slider.swift

import SwiftUI

struct ContentView: View {
    @State var isExpanded: Bool = false
    @State var width: CGFloat = 100
    
    var body: some View {
        ZStack(alignment: .leading) {
            Capsule()
            
            Capsule()
                .foregroundStyle(.green)
                .frame(width: width)
                .animation(.easeInOut, value: isExpanded)
        }
        .frame(height: isExpanded ? 25 : 10)
        .clipShape(Capsule())
        .gesture(
            DragGesture()
                .onChanged { value in
                    width = value.location.x
                    
                    withAnimation {
                        isExpanded = true
                    }
                }
                .onEnded { value in
                    withAnimation {
                        isExpanded = false
                    }
                }
        )
        .padding(.horizontal)
    }
}

#Preview {
    ContentView()
}