Chart Expands With Window But Not Shrink

[owenzhao]

//
//  ContentView.swift
//  Bar Chart Test
//
//  Created by zhaoxin on 2022/4/28.
//

import SwiftUI
import SwiftUICharts

struct ContentView: View {
    @State var data:BarChartData?

    var body: some View {
        ScrollView {
            VStack {
                if let data = data {
                    BarChart(chartData: data)
                        .touchOverlay(chartData: data, specifier: "%0.f KGs")
                        .xAxisGrid(chartData: data)
                        .yAxisGrid(chartData: data)
                        .xAxisLabels(chartData: data)
                        .yAxisLabels(chartData: data, specifier: "%0.f KGs")
                        .floatingInfoBox(chartData: data)
                        .headerBox(chartData: data)
                        .padding()

                    HStack {
                        Button {
                            data.dataSets.dataPoints.removeFirst()
                            data.dataSets.dataPoints.append(getRandomPoint())
                        } label: {
                            Text("Append Item")
                        }

                        Button {
                            changeMaxBarNumber()
                        } label: {
                            Text("Change Max Bar Number")
                        }
                    }
                } else {
                    ProgressView().onAppear {
                        let points = (1...10).map { _ in getEmptyPoint()}
                        let barStyle = BarStyle(barWidth: 0.5, colourFrom: .dataPoints)
                        data = BarChartData(dataSets: BarDataSet(dataPoints: points),
                                            barStyle: barStyle)
                    }
                }
            }
        }
        .padding()
        .frame(minWidth: 800, minHeight: 350)
    }

    private func getRandomPoint() -> BarChartDataPoint {
        let i = Int.random(in: 50...100)
        return BarChartDataPoint(value: Double(i), xAxisLabel: String(i),
                                 colour: ColourStyle(colour: .green))
    }

    private func getEmptyPoint() -> BarChartDataPoint {
        return BarChartDataPoint(value: 0, xAxisLabel: nil, colour: ColourStyle(colour: .green))
    }

    private func changeMaxBarNumber() {
        let maxBarNumber = Int.random(in: 10...20)
        var points = data!.dataSets.dataPoints.filter { $0.value != 0 }
        let count = points.count

        guard let data = data else {
            fatalError()
        }

        if count < maxBarNumber {
            let emptyPoints = (1...(maxBarNumber - count)).map { _ in getEmptyPoint() }
            points.insert(contentsOf: emptyPoints, at: 0)

            data.dataSets = BarDataSet(dataPoints: points)
        } else {
            data.dataSets = BarDataSet(dataPoints: Array(points[(count - maxBarNumber)...]))
        }
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}

https://user-images.githubusercontent.com/2182896/171357724-cb0414e5-8a55-4178-85c0-844794a50c8f.mov