KeyModifiers in button click event

Is your feature request related to a problem? Please describe. It is a common use case to identify any modifier key is pressed when a button is clicked, either with pointer or keyboard. In button definition, both PointerEventArgs and KeyEventArgs carries KeyModifiers, but when forwarding to OnClick method, this information is lost. It would be helpful to pass this information to OnClick method, otherwise I have to override all key/pointer methods when inheriting from Button.

Describe the solution you’d like

class ClickEventArgs:RoutedEventArgs
{
    public KeyModifiers KeyModifiers { get; }
}

internal interface IClickableControl
{
    event EventHandler<ClickEventArgs> Click;
}

Describe alternatives you’ve considered

Additional context my actual use case:

protected override void OnApplyTemplate(TemplateAppliedEventArgs e)
{
    base.OnApplyTemplate(e);
    var button = e.NameScope.Find<RepeatButton>("PART_Button");
    button.Click += OnButtonClick;
}

private void OnButtonClick(object? sender, RoutedEventArgs args)
{
    // When Shift is pressed, use logic 1, else use logic 2.
}
``

[maxkatz6]

@rabbitism as discussed, we think it’s a good idea to have RoutedEventArgs.Inner.

1. It needs clear remark that it’s not guaranteed to be of any specific value at any time.
2. ClickEventArgs, ContextMenuRequested, PointerEntered/PointerExited can be first to implement support. I guess some controls might also benefit from it (expander, spinner?).
3. We are not sure if this property should be mutable or init-only. If it can be init-only, that’s probably better for the beginning.

[rabbitism]

@maxkatz6 i will think about it. Inner need to be immutable, or there will be infinite loop when getting most inner exception.