ios – Swift Charts: How one can forestall scroll place bounce when loading extra knowledge dynamically

I am implementing infinite scrolling with Swift Charts the place extra historic knowledge masses when scrolling close to the start of the dataset. Nevertheless, when new knowledge is loaded, the chart’s scroll place jumps unexpectedly.

Present conduct:

• Initially masses 10 knowledge factors, displaying the newest 5
• When scrolling backwards with solely 3 factors remaining off-screen, triggers loading of 10 extra historic factors
• After loading, the scroll place jumps to the third place of the brand new dataset as an alternative of sustaining the present view

Anticipated conduct:

• Scroll place ought to stay secure when new knowledge is loaded
• Person’s present view mustn’t change throughout knowledge loading

Here is my implementation logic utilizing some mock knowledge:

import SwiftUI
import Charts

struct DataPoint: Identifiable {
  let id = UUID()
  let date: Date
  let worth: Double
}

class ChartViewModel: ObservableObject {
  @Revealed var dataPoints: [DataPoint] = []
  non-public var isLoading = false
  
  init() {
    loadMoreData()
  }
  
  func loadMoreData() {
    guard !isLoading else { return }
    
    isLoading = true
    
    let newData = self.generateDataPoints(
      endDate: self.dataPoints.first?.date ?? Date(),
      depend: 10
    )
    
    self.dataPoints.insert(contentsOf: newData, at: 0)
    self.isLoading = false
    
    print("(dataPoints.depend) knowledge factors.")
  }
  
  non-public func generateDataPoints(endDate: Date, depend: Int) -> [DataPoint] {
    var factors: [DataPoint] = []
    let calendar = Calendar.present
    
    for i in 0..?
  
  init() {
    self.scrollPosition = .now.addingTimeInterval(-4*24*3600)
  }
  
  var physique: some View {
    Chart(viewModel.dataPoints) { level in
      BarMark(
        x: .worth("Time", level.date, unit: .day),
        y: .worth("Worth", level.worth)
      )
    }
    .chartScrollableAxes(.horizontal)
    .chartXVisibleDomain(size: 5 * 24 * 3600)
    .chartScrollPosition(x: $scrollPosition)
    .chartXScale(area: .computerized(includesZero: false))
    .body(peak: 300)
    .onChange(of: scrollPosition) { oldPosition, newPosition in
      scrollDebounceTask?.cancel()
      
      scrollDebounceTask = Job {
        strive? await Job.sleep(for: .milliseconds(300))
        
        if !Job.isCancelled {
          checkAndLoadMoreData(currentPosition: newPosition)
        }
      }
    }
  }
  
  non-public func checkAndLoadMoreData(currentPosition: Date?) {
    guard let currentPosition,
          let earliestDataPoint = viewModel.dataPoints.first?.date else {
      return
    }
    
    let timeInterval = currentPosition.timeIntervalSince(earliestDataPoint)
    
    if timeInterval <= 3 * 24 * 3600 {
      viewModel.loadMoreData()
    }
  }
}

What’s the issue with my code and the right way to repair it?