VS Code contributes.menus的when字段可用变量咨询

Great question! Let's break this down into two clear sections: first, the general variables supported in when clauses, then the extra (and still applicable general) variables you can use when targeting markdown files specifically.

General Variables for when Clauses #

These variables cover all kinds of contexts in VS Code, from editor state to file properties. Here are the most commonly used ones:

Editor & Text Context #

• editorFocus: True when any text editor has focus.
• editorHasSelection: True if you've selected text in the active editor.
• editorLangId: The language ID of the active editor's document (e.g., javascript, python—similar to resourceLangId, but tied to the editor rather than the file resource).
• editorTabCount: Number of open editor tabs in the window.

File & Resource Context #

• resourceLangId: The language ID of the focused file (this is the one from your example, set to markdown for .md files).
• resourceScheme: The URI scheme of the file—like file for local files, untitled for unsaved drafts, or vscode-vfs for virtual files.
• resourceExtname: The file extension (e.g., .md, .js) of the focused resource.
• resourcePath: Full file system path of the resource.
• resourceBasename: The full filename (including extension, like README.md).

Workspace & Window Context #

• workspaceFolderCount: Number of folders open in your workspace.
• windowFocus: True when the VS Code window is the active window on your desktop.
• inDebugMode: True when the debugger is running or paused.

View & UI Context #

• viewItem: For tree views (like the Explorer), refers to the currently selected item—you can check its properties, e.g., viewItem == 'explorer-file'.
• inputFocus: True when any input field (like the command palette or a search box) has focus.

Variables for resourceLangId == markdown Scenarios #

When you're targeting markdown files, all the general variables above still work, plus VS Code exposes markdown-specific variables tailored to the markdown editor and preview:

• markdown.showPreview: True when the markdown preview panel is visible (even if it's not focused).
• markdown.previewFocus: True when the markdown preview panel has focus (instead of the source editor).
• markdown.editorFocus: True when the markdown source editor has focus (useful if you want to distinguish between editing and previewing).
• markdown.isInPreview: True if the active view is the markdown preview (rather than the source file).

Example Combinations #

You can mix these with general variables for precise conditions:

• Show a menu item only when editing markdown and have text selected:

  "when": "resourceLangId == markdown && editorHasSelection"
  

• Show an item only in the markdown preview:

  "when": "resourceLangId == markdown && markdown.isInPreview"
  

Remember, you can use logical operators (&&, ||, !) to build complex conditions that fit your exact use case.

内容的提问来源于stack exchange，提问作者original.roland