ListBox with Virtualization="None" selected pseudoclass incorrect after move

[aguahombre]

Using build 0.8.999-cibuild0003548-beta.
Calling the Move method of an ObservableCollection bound to a ListBox with VirtualizationMode="None" causes the ListBox's selected items to go crazy.

Here is a repo:
Initial selection is A (index 0).

After pressing the Move button several times, the selected pseudoclass is present on multiple items.

<Window xmlns="https://github.com/avaloniaui"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        mc:Ignorable="d" d:DesignWidth="800" d:DesignHeight="450"
        x:Class="AvaloniaApplication11.MainWindow"
        Title="AvaloniaApplication11">
  <Window.Styles>
    <Style Selector="ListBoxItem:selected /template/ ContentPresenter">
      <Setter Property="ContentTemplate">
        <DataTemplate>
          <Border BorderBrush="Crimson" BorderThickness="2" >
            <TextBlock Text="{Binding}"/>
          </Border>
        </DataTemplate>
      </Setter>    
    </Style>
  </Window.Styles>
  <Grid RowDefinitions="Auto,*">
    <Grid ColumnDefinitions="*,*,*">
      <Button Grid.Column="0" Content="Move" Command="{Binding Move}"/>
      <TextBlock Grid.Column="1" Text="{Binding #listbox.SelectedIndex, StringFormat=SelectedIndex \{0\}}"/>
      <TextBlock Grid.Column="2" Text="{Binding #listbox.SelectedItem, StringFormat=SelectedItem \{0\}}"/>
    </Grid>
    <ListBox Grid.Row="1" Name="listbox" SelectedIndex="0" Items="{Binding Items}" VirtualizationMode="None" />
  </Grid>
</Window>

using System.Collections.ObjectModel;
using Avalonia.Controls;
using Avalonia.Markup.Xaml;

namespace AvaloniaApplication11
{
    public class MainWindow : Window
    {
        private ListBox _listbox;
        bool _down;

        public ObservableCollection<string> Items { get; } = new ObservableCollection<string>(new[] { "A", "B", "C", "D", "E", "F", "G", "H", "I", });
        public MainWindow()
        {
            DataContext = this;
            AvaloniaXamlLoader.Load(this);

            _listbox = this.FindControl<ListBox>("listbox");
        }

        public void Move()
        {
            if (_listbox.SelectedIndex < 0)
            {
                _listbox.SelectedIndex = 0;
            }

            if (_down)
            {
                if (_listbox.SelectedIndex < Items.Count - 1)
                {
                    Items.Move(_listbox.SelectedIndex, _listbox.SelectedIndex + 1);
                }
                else
                {
                    _down = false;
                    Items.Move(_listbox.SelectedIndex, _listbox.SelectedIndex - 1);
                }
            }
            else
            {
                if (_listbox.SelectedIndex > 0)
                {
                    Items.Move(_listbox.SelectedIndex, _listbox.SelectedIndex - 1);
                }
                else
                {
                    _down = true;
                    Items.Move(_listbox.SelectedIndex, _listbox.SelectedIndex + 1);
                }
            }
        }
    }
}

[danwalmsley]

@aguahombre we recently made a fix to resolve a similar issue, can you confirm if this is still an issue?

[aguahombre]

No the problem is not fixed but has changed in 0.8.999-cibuild0004187-beta

Starting with A selected

If I click the Move button which calls ObservableCollection Move method to move A to index 1, I get the following output

As you can see, both A and C are shown as selected, whereas only A should be selected.

[aguahombre]

This is still an issue in 0.8.999.
See new incorrect behaviour above.
Must have closed this by accident!

[grokys]

@aguahombre for 0.10 i'm hoping to use ItemsRepeater to handle our ListBox virtualization, which should fix this. However that means that it's unlikely to be fixed in the near term if there's a workaround.

Would you be able to do a remove/insert instead of a move as a workaround?

[aguahombre]

Thanks, will use workaround for now