Setting a Foreground on a SplitButton does not apply to the dropdown half

[zadjii-msft]

re: microsoft/terminal#13871

See source:

microsoft-ui-xaml/dev/SplitButton/SplitButton.xaml

Lines 290 to 293 in 3373245

	<Button x:Name="SecondaryButton"
	Grid.Column="2"
	Foreground="{ThemeResource SplitButtonForegroundSecondary}"
	Background="{TemplateBinding Background}"

We were setting Foreground on the SplitButton we use as our new tab button. However, the visual styles for the secondary button use Foreground="{ThemeResource SplitButtonForegroundSecondary}" , so they'll just always ignore the Foreground property (even if the primary button respects it).

Also, this seems to have regressed in #3887, which first shipped in 2.6.1

https://github.com/microsoft/microsoft-ui-xaml/blame/33732458ede38166f9127675898e4760c82b89bb/dev/SplitButton/SplitButton.xaml#L292

If this is by design, that's fine - but it should be documented as such.

[github-actions]

This issue is stale because it has been open 180 days with no activity. Remove stale label or comment or this will be closed in 5 days.

[zadjii-msft]

Nothing has changed here ; still an issue.

[karkarl]

Hey @zadjii-msft, this is by design, since SplitView's primary and secondary texts uses different brush colours. Templatebinding both elements to SplitView.Foreground will not allow them to consume different brushes, and ultimately remove flexibility in customization.

I agree much work should be done in terms of documentation since it's not immediately obvious what element Foreground (nor Background) sets. Happy to discuss further for ideas.