How to know if the markdown preview is focused using contributes commands - VSCode Extension API

Question

I'm looking for something similar to "when": "markdownPreviewFocus" which is mentioned in vscode package.json . unfortunately, when I try it shows that markdownPreviewFocus is not supported in when condition.

"editor/title": [
    {
        "command": "extension.my_command",
        "when": "markdownPreviewFocus==false",
        "group": "navigation"
    }
]

Answer 1

尝试：

`"when": "!markdownPreviewFocus"`