title: SwiftUI animating expand and collapse of list rows
body: <p>I'm using SwiftUI to animate an expand and collapse in a list.</p>
  
  <p>How can I get the height expansion of the section to animate smoothly like it would in UIKit with a tableview?</p>
  
  <pre><code>struct Rows: View {
      let rows = ["Row 1", "Row 2", "Row 3", "Row 4", "Row 5"]
  
      var body: some View {
          Section {
              ForEach(rows.identified(by: \.self)) { name in
                  Text(name)
                      .lineLimit(nil)
              }
          }
      }
  }
  
  struct Header: View {
  
      @State var isExpanded: Bool = false
  
      var body: some View {
  
          VStack(alignment: .leading) {
              Button(action: {
                  self.isExpanded.toggle()
  
              }) {
                  Text(self.isExpanded ? "Collapse Me" : "Expand Me")
                      .font(.footnote)
              }
  
              if self.isExpanded {
                  Rows().animation(.fluidSpring())
              }
          }
      }
  }
  
  struct ContentView : View {
  
      var body: some View {
          List(0...4) { _ in
              Header()
          }
      }
  }
  </code></pre>
  
  <p>The animation seems to only apply to the text in the rows not the actual height or separator line growing to accommodate the new rows. The row text also seems to start animating from the very top of the row rather than where it appears in the view hierarchy. I need a smooth animation.</p>