Add a fun new preview text in the SUI, enable the cursor

[DHowett]

Our existing preview text was not very helpful in learning how different settings impacted the display of text in Terminal.

This new preview text contains:

• Bold text, which is controlled by intenseTextStyle
• Colors
• Emoji
• A cursor, which overlaps a single character to show inversion behavior

[DHowett]

[DHowett]

I have something even MORE fun, but i was holding it for after this...

[DHowett]

blur is the opposite of focus, don't at me

[lhecker]

I'm not happy about the DisplayCursorWhileBlurred because it's a hack. It would probably make more sense if it was part of the unfocused appearance as a proper setting. It might be worthwhile to note in the .idl that the setting is bodgy/hacky.

[DHowett]

I'm not happy about the DisplayCursorWhileBlurred because it's a hack.

I agree, but I did look at other XAML properties like AllowFocusWhenDisabled and stuff. There is precedent for these weird single-shot properties.

I do think we should fix Unfocused Appearances, but in general doing that will utterly F up the settings UI preview because it is always unfocused... SO WE WILL STILL NEED A HACK 😁

[lhecker]

I do think we should fix Unfocused Appearances, but in general doing that will utterly F up the settings UI preview because it is always unfocused... SO WE WILL STILL NEED A HACK 😁

We could technically just separate out the WinUI and non-WinUI parts from the _GotFocusHandler and _LostFocusHandler and expose the latter as a property. This would allow you to switch between the two appearances at will. I do agree though that we can do something like this at a later time (unless you feel like this would be easy to implement?). As you mentioned, there's a lot of subjective design issues in the area already that we'd probably need to address.