Default Placement of Rotate Object

How do we make the rotate circle appear at the top of the object instead of at the right by default.

Draggable link sample gives an example of customizing the rotating tool adornment, and one of its customizations is placing the handle at the top: http://gojs.net/latest/samples/draggableLink.html

There is a custom RotatingTool in the http://gojs.net/latest/samples/draggableLink.html sample. Just copy the TopRotatingTool into your code, and replace the Diagram.toolManager.rotatingTool with an instance of the TopRotatingTool.

If you want, you can customize the Part.rotateAdornmentTemplate, as that sample also does. But this is optional.