Currently, the widget controller display widgets that are listed in the widget panel. You could make it look like it is part of the widget controller by adding a button widget to the end so you can launch the window.
Hi David, how do I set the button to open the window when you click? At the moment it's just a pop-up text panel with a button in it, which is not very clear/intuitive for the user?
By the looks of that panel, it looks like you're adding the button widget through the controller widget. Add a button widget through the widget panel, not through the controller, and in the settings-->content-->advanced-->corner enter in 100 px for all those settings to give you the circle shape. In the style tab, set the width and height to 32px. You will have to adjust the position settings to find that right alignment with the widget controller. I found it easier to add that widget to the end of the controller because you cannot add that widget inside the widget controller.