Widgets and Context Menu/Right-click

Hi guys,

I created a custom plugin for CKEditor 3  ages ago but recently upgraded to v4. I was intrigued by the new widgets system and I have completed converting the whole plugin apart from one part - the right click menu. My old plugin would write a div with a certain data attribute and when it detected a right-click on it it would show a menu item where the plugin's dialog would appear with the relevant info filled in.

Unfortunately I cannot find any documentation on how to replicate this for a widget nor have I had any success just tinkering and am now at a stop. 

Is there a method for having custom context menu items when right-clicking a widget?

Thanks in advance,

Andrew.