using System;
using System.Collections;
using System.Reflection;
using System.Windows.Forms;

namespace FastReport.Controls
{
    internal sealed class ExtListView : ListView
    {
        public event EventHandler FetchMoreItems;

        public ExtListView()
        {
            var pi = this.Controls.GetType().GetProperty("ImplicitControls", BindingFlags.NonPublic | BindingFlags.Instance);
            if (pi != null)
            {
                var arrayList = pi.GetValue(this.Controls) as ArrayList;
                if (arrayList != null)
                {
                    foreach (var item in arrayList)
                    {
                        if (item is VScrollBar sc)
                        {
                            sc.ValueChanged += (s, e) =>
                            {
                                if (sc.Maximum - sc.LargeChange <= sc.Value)
                                {
                                    FetchMoreItems?.Invoke(this, e);
                                }
                            };
                        }
                    }
                }
            }
        }
    }
}