How do you show the current position coordinates of the mouse?

You would have to register a MouseListener to the DOM node of the map's graphics context, which is accessible through map.getGraphics.getNode(). The map itself can be obtained using e.g. dijit.byId("mainMap"). The way the map widget works is that there is a single controller responsible for processing mouse events. This controller is set via the setController() function and will change whenever the user selects a different tool in the toolbar. Therefore, it probably makes more sense to not use the setController() function but instead add a separate "background" listener to monitor the current position.

The code would be as follows:

var map = dijit.byId("mainMap");
 var node = map.getGraphics.getNode();
 var subject = new MouseListenerSubject (node, 30); // 30 is the minimal time in millis between mouse move events
 subject.addListener();