How to get default system padding value?

Question

I'm using SwiftUI but I've created a representable UITextView.

I want to set the insets to the system default padding so it matches the rest of the app.

Here is what I'm using right now:

UITextView().textContainerInset = UIEdgeInsets(top: 15, left: 15, bottom: 15, right: 15)

This looks decent but I would really prefer to utilize the default system padding, if possible.

The documentation for padding() states the following:

length

The amount to inset this view on each edge. If nil, the amount is the system default amount.

How do I obtain the default system padding CGFloat value?

Answer 1

So, I made a rectangle with width/height as 0 and the default padding on top, then I read the height of the rectangle (which is the size of the default padding) and store it in a bound CGFloat. It also hides itself.

You could then pass that value into your UITextView wrapper.

struct Defaults: View {
    @Binding var padding: CGFloat
    @State var isHidden = false
    @ViewBuilder
    var body: some View {
        if !isHidden {
            Rectangle()
                .frame(width: 0, height: 0)
                .padding(.top)
                .background(GeometryReader { geometry in
                    Rectangle().onAppear {
                        self.padding = geometry.size.height
                        self.isHidden = true
                    }
                })
        }
    }
}


struct Example: View {
    @State var padding = CGFloat()
    @ViewBuilder
    var body: some View {
        Defaults(padding: $padding)
        Rectangle().frame(width: padding, height: padding)
    }
}