using System.Windows.Input;
using System.Windows;
using System.Windows.Controls;
using System;
using System.ComponentModel;
using System.Windows.Media;

namespace CustomControls
{
    [DesignTimeVisible(false)]
    public partial class ListView : System.Windows.Controls.ListView
    {
        public event EventHandler CancelEdit;
        public event EventHandler AcceptEdit;
        public event EventHandler FetchMoreItems;

        private void OnAcceptEdit() => AcceptEdit?.Invoke(this, EventArgs.Empty);

        private void OnCancelEdit() => CancelEdit?.Invoke(this, EventArgs.Empty);

        private void PART_TextBox_IsVisibleChanged(object sender, DependencyPropertyChangedEventArgs e)
        {
            var tb = sender as TextBox;
            if (tb.IsVisible)
            {
                tb.Focus();
                tb.SelectAll();
            }
        }

        private void PART_TextBox_LostFocus(object sender, RoutedEventArgs e)
        {
            OnCancelEdit();
        }

        private void PART_TextBox_KeyDown(object sender, KeyEventArgs e)
        {
            if (e.Key == Key.Escape)
            {
                OnCancelEdit();
                e.Handled = true;
            }
            else if (e.Key == Key.Enter)
            {
                OnAcceptEdit();
                e.Handled = true;
            }
        }

        private void ListView_ScrollChanged(object sender, ScrollChangedEventArgs e)
        {
            if (e.VerticalOffset > 0 && e.ExtentHeight - e.ViewportHeight <= e.VerticalOffset)
            {
                FetchMoreItems?.Invoke(this, EventArgs.Empty);
            }
        }

        public ListView()
        {
            InitializeComponent();
        }
    }
}