Add glyph for deprecated members in intellisense dropdown

[davidfowl]

Today when you use a deprecated API the intellisense shows it as deprecated:

It would be nice if we showed that the member was deprecated via a glyph in the intellisense dropdown.

[Pilchie]

Tagging @kuhlenh and @markw-t. I wonder if we could re-use the warning glyph for when something isn't available in all heads here (potentially with a different glyph).

[kuhlenh]

@Pilchie @markw-t -- yes! Ideally, we can nicely group our intellisense glyph changes together (different glyph for the smart variable name suggestions).

[markw-t]

I seem to recall that something similar was proposed for shared project cases. Seems a good idea to make the icon show the deprecation too, I agree.

[mhutch]

FWIW, in VSMac we designate these with a strikethrough in the completion list.

[davidfowl]

Unknown milestone 😞

[CyrusNajmabadi]

@markw-t Would it be costly to be able to add strikethrough capabilities to the completion presentation layer?

[Pilchie]

Didn't we used to have support for strikethrough or greying out to support "IntelliSense in Zone" for partial trust click once apps?

[genlu]

@sharwell I thought you implemented this recently, but apparently it's only for the classification but not in completionlist?

[CyrusNajmabadi]

@olegtk is there some flag in the completion list api to strikethrough a completion item?

[JoeRobich]

Maybe our VSCompletionItem can implement ITextFormattable and provide the strikethrough text decoration. haha strike that thought.

[olegtk]

@CyrusNajmabadi not yet, tracked by https://devdiv.visualstudio.com/DevDiv/_workitems/edit/2225286
But we do support strikethrough via ClassifiedTextRunStyle.Strikethrough starting with 17.14 Preview1 so I guess you can use it in completion tooltip already, but not in the completion item itself.

[CyrusNajmabadi]

Ok. We'll wait on the completion work being done. If/when that happens, can you let us know so we can move on this? Thanks!