An example of a label that grows and shrinks in overall size and frame height. Requires FrameUp https://github.com/ryanlintott/FrameUp

ShrinkingLabel.swift

//
//  ShrinkingLabel.swift
//  FrameUpExample
//
//  Created by Ryan Lintott on 2024-02-21.
//

import FrameUp
import SwiftUI

struct ShrinkingLabel: View {
    @Binding var isFocused: Bool

    @State private var textSize: CGSize? = nil
    
    let text: Text
    
    var scale: CGFloat {
        isFocused ? 1 : 0.6
    }
    
    var adjustedHeight: CGFloat? {
        guard let textSize else { return nil }
        return textSize.height * scale
    }
    
    var body: some View {
        text
            .frame(maxWidth: .infinity, alignment: .leading)
            .fixedSize(horizontal: false, vertical: true)
            .onSizeChange { newValue in
                textSize = newValue
            }
            .scaleEffect(scale, anchor: .topLeading)
            .frame(maxHeight: adjustedHeight, alignment: .top)
    }
}

struct ShrinkingLabelExample: View {
    @State private var isFocused = false
    
    var body: some View {
        VStack(alignment: .leading, spacing: 10) {
            Text("Example with scaleEffect that will not adjust the frame.")
            
            Text("Here is a label with some long text that will span two lines.")
                .scaleEffect(isFocused ? 1 : 0.7, anchor: .bottomLeading)
            
            Text("Example with FrameUp that will adjust the frame.")
            
            ShrinkingLabel(isFocused: $isFocused, text: Text("Here is a label with some long text that will span two lines."))
            
            Toggle("isFocused", isOn: $isFocused)
        }
        .animation(.easeInOut, value: isFocused)
        .padding()
        .frame(maxHeight: .infinity, alignment: .top)
    }
}

#Preview {
    ShrinkingLabelExample()
}