Allow QuickPickItem to have file icons

[karthiknadig]

Currently, there is no explicit way to set the theme icon for items in QuickPickItem, Terminal, TreeViewItem to a specific language Icon.

TreeView supports an indirect way where you need to set resourceUri to a file (like something.py), and iconPath to ThemeIcon.File. This allows core to calculate the icon. But there is no way to say iconPath = new ThemeIcon('python').

Such a feature is not available in QuickPicks or Terminal (iconPath). For QuickPick, the uses cases include selecting a start-up script or set of files for some task. For, Terminal, in python extension we can have dedicated terminal per file, and we would like to show the icon of the file there.

Related: #124363 , #59826

[TylerLeonhardt]

Martin owns ThemeIcon's... I'll let him drive this one. If you want a separate issue that is specific to QuickPick having a resourceUri like Trees, please create one and assign that to me.

[aeschli]

There are two different types of icons:

• file icons: they are defined by the current file icon theme. There are file icon themes that don't show icons, and there are file icon themes that show the same icon for all files. Maybe there's an icon for python in there, maybe there are multiple as associations are based on file name, file extension and folder name and language
• product icons: A set of named icons. The ones you can reference in ThemeIcon

If your goal is to have the same icon as in the explorer or editor title: then use ThemeIcon.FILE and set a resource. We need a resource name for that given the multiple ways that associations work. The resource doesn't have to exist.

If you want to have a Python icon that is always available, but might not match what's in the explorer:
Ask for a new codicon for an icon called 'Python'

There's one thing we could do. Language providers have a way to contribute a default icon. It is used as a file icon if a file icon theme shows icons does not define an icon for a language. We could also register that one as a product icon.

• Only very few languages do that. Basically only exotic languages that are unknown to most file icon themes
• That icon will in the most cases not match the icon from file icon theme.

[karthiknadig]

For Quickpick, Terminal, I want the file icons, that would address the issue that I have.

[aeschli]

Ok, then assigning this issue to @TylerLeonhardt for Quick Pick...

[TylerLeonhardt]

Based on the response @aeschli doesn't think we should allow the language id in the ThemeIcon and Karthik is satisfied with that answer so long as we address the gaps in QuickPick and Terminal APIs.

I already have a quick pick one #59826

@karthiknadig were you able to find a Terminal one?

If not, can you open one?
If so, or once that's opened, then we can mark this as a dupe of those, I think.

[karthiknadig]

@TylerLeonhardt Created #233354 for Terminals

[Tyriar]

Should we close this in favor of #59826?