Allow TreeItem.label to support MarkdownString

[TylerLeonhardt]

Looking at the API for TreeItemLabel it seems a bit limited. I'm trying to avoid moving to a webview view and what I need is some way to have certain nodes in a tree view be crossed out. It'd be nice if TreeItem.label could be extended to support MarkdownString.

Proposal:

export class TreeItem {
		/**
		 * A human-readable string describing this item. When `falsy`, it is derived from [resourceUri](#TreeItem.resourceUri).
		 */
		label?: string | TreeItemLabel | MarkdownString;
}

[alexr00]

I am not adverse to to this proposal. @TylerLeonhardt would you be interested in bringing the proposal to the API sync?

[connor4312]

I wonder if we should support MarkdownString (with a subset of functionality) instead of introducing new semantics for text styles.

[TylerLeonhardt]

Interesting... So every TreeItem can only be rendered on 1 line, however, multiple lines is technically supported in the hover:

In theory, the full extent of MarkdownString could be supported in the hover, but I think there's a lot of MarkdownString that doesn't make sense for the label:

• Headings
• Table
• Code block
• Quote block
• Lists
• Images
• Links? (since that would interfere with click event handler)

Which leaves:

• Strikethrough
• Bold
• Italics
• Inline code

I wonder if that would cause confusion.

[lukaschneider]

Hey,
I am currently working on an extension which enables a user to open packet traces in vscode. While prototyping I came across this issue.

Having an option to use a monospaced font would improve readability a lot in my case.

Before:

After:

[TylerLeonhardt]

Updated issue to move to MarkdownString per API Sync feedback.

[P403n1x87]

It would be nice if colours were supported too, but I believe this not something that could be achieved with a MarkdownString? Would it make sense to have a way to bypass escaping when setting the label value and allow nested span objects?

[mkloar]

It would be nice if colours were supported too, but I believe this not something that could be achieved with a MarkdownString? Would it make sense to have a way to bypass escaping when setting the label value and allow nested span objects?

Yeah, I would be great if vscode API will support colours.

[generateui]

Interesting... So every TreeItem can only be rendered on 1 line, however, multiple lines is technically supported in the hover:

In theory, the full extent of MarkdownString could be supported in the hover, but I think there's a lot of MarkdownString that doesn't make sense for the label:

* Headings

* Table

* Code block

* Quote block

* Lists

* Images

* Links? (since that would interfere with click event handler)

Which leaves:

* Strikethrough

* Bold

* Italics

* Inline code

I wonder if that would cause confusion.

It would make snese to me when vscode has a differentiator: MarkdownBlockString and MarkdownInlineString. After all, close to all apis/asts/parsers I have seen make this distinction.

[jedwards1211]

I'm working on a semantic search and replace extension and I still can't replicate the appearance of the builtin find/replace results with the existing TreeView API.

[dustinlacewell]

Please prioritize this as it's quite limiting to the UX of TreeView based extensions. Thanks.

[whitequark]

I would also like to use this capability in a debugger extension that cannot utilize the debugger API (it's not a debugger for software). Colors would be extremely useful.

[EhabY]

When implementing this please take into account coloring the label (or parts thereof), possibly using ThemeColor. Currently the only way to color a label is to use a FileDecorationProvider but that is global and applies the color to the full label - We want something that is for a single TreeItem only.