ColorPicker shows spectrum tab even when disabled and SelectedIndex doesn't work

When disabling the Spectrum tab on a ColorPicker it is still shown when the ColorPicker is first opened. Adding the SelectedIndex property to force it onto the Palette tab does not work.

<ColorPicker SelectedIndex="1" IsColorSpectrumVisible="False"/>

After trying several ways to get the Palatte tab to open first time I managed to get it working with reflection and a subclass.

<extensions:ExtendedColorPicker SelectedIndex="1" IsColorSpectrumVisible="False"/>

public class ExtendedColorPicker : ColorPicker, IStyleable {
    
    public Type StyleKey { get; } = typeof(ColorPicker);

    private int selectedTabIndex;
    
    protected override void OnApplyTemplate (TemplateAppliedEventArgs e) {
        // There might be a property set in xaml that get's overridden here
        selectedTabIndex = SelectedIndex;
        base.OnApplyTemplate(e);
    }

    protected override void OnLoaded () {
        base.OnLoaded();
        var type = typeof(ColorView);
        if (type.GetField("_tabControl", BindingFlags.Instance | BindingFlags.NonPublic)?.GetValue(this) is not TabControl tabControl) return;
        tabControl.SelectedIndex = selectedTabIndex;
    }
}

Desktop (please complete the following information):

• OS: Windows 10
• Version 11.0.0-preview4

[SkywardRay]

I’m sorry. I just realized that the project is not visible on Gitlab, I thought I set it to public but it’s not letting me. Here it is on Github instead https://github.com/SkywardRay/AvaloniaTestColorPicker

[robloo]

The more I think about this, I think it might be an issue with the TabControl and best fixed there. The TabControl is literally showing tab content when the tab is hidden. This probably shouldn’t happen and the TabControl itself needs to ensure the SelectedIndex is always valid.

I might change the approach here completely and address this in TabControl.