PowerToys/src/modules/launcher/PowerLauncher/ResultListBox.xaml.cs

using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;

namespace PowerLauncher
{
    public partial class ResultListBox
    {
        protected object _lock = new object();
        private Point _lastpos;
        private ListBoxItem curItem = null;
        public ResultListBox()
        {
            InitializeComponent();
        }

        private void OnSelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            if (e.AddedItems.Count > 0 && e.AddedItems[0] != null)
            {
                ScrollIntoView(e.AddedItems[0]);
            }
        }

        private void OnMouseEnter(object sender, MouseEventArgs e)
        {
            lock(_lock)
            {
                curItem = (ListBoxItem)sender;
                var p = e.GetPosition((IInputElement)sender);
                _lastpos = p;
            }
        }

        private void OnMouseMove(object sender, MouseEventArgs e)
        {
            lock(_lock)
            {
                var p = e.GetPosition((IInputElement)sender);
                if (_lastpos != p)
                {
                    ((ListBoxItem)sender).IsSelected = true;
                }
            }
        }

        private void ListBox_PreviewMouseDown(object sender, MouseButtonEventArgs e)
        {
            lock(_lock)
            {
                if (curItem != null)
                {
                    curItem.IsSelected = true;
                }
            }
        }
    }
}