SwiftUI - Animate height of rectangle from 0 to height - swift

Question

I am attempting to animate the height of a RoundedRectangle() from 0 to its new height, I would like it to grow from its current position upwards when my device shakes. As it currently stands, I have a onShake function which I want to activate the growing of the rectangle.
struct View1: View {
var body: some View {
ZStack {
Color.white
.edgesIgnoringSafeArea(.all)
Text("Hola")
.foregroundColor(.black)
.font(.headline)
RoundedRectangle(cornerRadius: 5)
.frame(width: 100, height: 0, alignment: .center)
.foregroundColor(Color("RedColour"))
.onShake {
withAnimation {
self.frame(width: 100, height: 100)
}
}
}
}
}
As you can probably tell I am very new to SwiftUI and have very limited knowledge of how animations work. Feel free to grill me for it, but I would also love some help with attempting to grow this rectangle upwards when my device shakes.
Much love!

Answer 1

You could try this. But as the information you provided do not include how you want to use this, this might be incomplete.
struct View1: View {
#State private var height: CGFloat = 0 // add this to modify
// the height of the Rounded Rectangle
let targetHeight: CGFloat = 100 // targetHeight var to syncronise with the VStack
var body: some View {
ZStack {
Color.white
.edgesIgnoringSafeArea(.all)
Text("Hola")
.foregroundColor(.black)
.font(.headline)
.background{
VStack{
Spacer(minLength: 0)
RoundedRectangle(cornerRadius: 5)
.frame(width: 100, height: height)
.foregroundColor(.red)
.onShake {
withAnimation(.linear(duration: 5)) {
height = targetHeight
}
}
}.frame(height: targetHeight) // VStack with fixed height
//to animate from bottom up
}
}
}
}