How to make a square button when using scaled sizing?

I think I just answered my own question.  This seems to be working well:

	<Style Selector="Button.image">
		<Setter Property="Template">
			<ControlTemplate>
				<Border
					Background="{TemplateBinding Background}"
					BorderBrush="{TemplateBinding BorderBrush}"
					BorderThickness="{TemplateBinding BorderThickness}"
					CornerRadius="{TemplateBinding CornerRadius}"
					Width="{Binding $self.Bounds.Height}">
					<Viewbox Width="16" Height="16">
						<PathIcon Data="{TemplateBinding Tag}"/>
					</Viewbox>
				</Border>
			</ControlTemplate>
		</Setter>
	</Style>

Now how can I set my button height to equal the same height as other controls such as a one line TextBox or ComboBox when no other contorls are present in the control collection such as a StackPanel?

Hello,

That is tough since you need the actual measurement of the other controls, which can vary widely based on font sizes, paddings, etc.

Your surefire way to get it would be to put a disabled TextBox in the same StackPanel but set its Width=0 and Opacity=0.

Yes that thought crossed my mind but it's super hacky so I didn't do that.