When using registerTextDocumentContentProvider, the view blocks Copy command

[cfjedimaster]

• VSCode Version: 1.1.1
• OS Version: OSX

I'm the author of a plugin (https://github.com/cfjedimaster/htmlescape-vscode) that takes code in the editor (or a selection), and creates a view of an escaped version of it. (This is so the code could be used in an HTML blog post.) Recently I noticed that while my extension works, selecting text in the view and trying to copy it to the clipboard no longer works.
Steps to Reproduce:

1. Install the extension (it is available in the market place).
2. Open any file, and execute the command ("Show Escaped HTML").
3. In the new view that opens up, select some of the escaped HTML, do Command-C, then paste in some other editor. Nothing will show up.

[jrieken]

do you use previewHtml?

[cfjedimaster]

No. From https://github.com/cfjedimaster/htmlescape-vscode/blob/master/src/extension.ts - I've implemented vscode.TextDocumentContentProvider. I'm using provideTextDocumentContent to get the text from the editor and create a new HTML document from it.

[jrieken]

well, you do this which is previewing the document as html. I wonder, if in your case and as a workaround, you could just openTextDocument and showTextDocument - then the editor will be used to display the virtual document.

[cfjedimaster]

Are you saying it would take over the default editor pane? If so, that's not what I want.

[jrieken]

default editor pane

Well, like previewHtml it open where editors open but you can define the column in which it shows and also if it should take focus or not: https://github.com/Microsoft/vscode/blob/master/src/vs/vscode.d.ts#L3018

[jrieken]

despite alternative implementations/workarounds to the problem, I believe this is #6924.