ContractCategoryModel.cs

using System.Collections.ObjectModel;
using System.ComponentModel;
using Microsoft.Maui.Controls.Shapes;
 
namespace NeuroAccessMaui.UI.Pages.Contracts.MyContracts.ObjectModels
{
    public class ContractCategoryModel(string Category, ICollection<ContractModel> Contracts) : ObservableCollection<ContractModel>, INotifyPropertyChanged
    {
        private bool expanded;
 
        public string Category { get; } = Category;
 
        public ICollection<ContractModel> Contracts { get; } = Contracts;
 
        public int NrContracts => this.Contracts.Count;
 
        public bool Expanded
        {
            get => this.expanded;
            set
            {
                if (this.expanded != value)
                {
                    this.expanded = value;
 
                    this.OnPropertyChanged(new PropertyChangedEventArgs(nameof(this.Expanded)));
                    this.OnPropertyChanged(new PropertyChangedEventArgs(nameof(this.Symbol)));
 
                    if (this.expanded)
                    {
                        foreach (ContractModel Contract in this.Contracts)
                            this.Add(Contract);
                    }
                    else
                        this.Clear();
                }
            }
        }
 
        public Geometry Symbol => this.expanded ? Geometries.FolderOpenPath : Geometries.FolderClosedPath;
    }
}