Explore showing workspace search results in the command center

[andreamah]

We want to start to explore what it'd be like to have a quickpick that shows text results.

For example, if we search activate in the vscode-livepreview repo, we don't get anything because it isn't in any filenames.

It would be nice if vscode knew that activate was in the extension.ts file and showed that file.

[gjsjohnmurray]

I started trying this our in Insiders. Initially didn't seem to work, until I realized it's vital to enter a space after the % character prefix.

[andreamah]

The reason why we need a space after the % is because we try to keep the same pattern as the other quick accesses

Edit: I just remembered that symbols like the command palette > don't automatically add a space. I was originally basing mine based on ones like debug where it'd make sense to have a space. I'll reconsider removing the space...

[gjsjohnmurray]

One argument for requiring a space is if the workspace has files whose names begin with %

[andreamah]

We now have a preliminary version of this. I will close this and additional requests regarding it can be in its own issue.