Place multiple windows of Word documents in the same parent window

Question

This addin adds "document tabs" to Microsoft Word, I wonder how this is done? As you know, in accordance with the Word 'Object Model' API, each Word document is associated with a stand-alone Word window , how can this addin put several windows of a Word document in the same parent window and use tabs to switch among them?

Attached screenshot to illustrate how this addin works:

Answer 1

I don’t know how this add-on does it on purpose, but if I were to guess, I would say that they put the word in MDI mode by creating addin ui tabs on them and then controlling the visibility of the individual doc windows when you click on the tabs .

You can put Word in MDI mode by unchecking the "Show all windows in the taskbar" checkbox.