The Navigator class contains information about the browser running the app, such as the product (the name of the browser), its vendor, the MIME type supports the installed plugins, and also the geolocation object.

Every browser window corresponds to an object of the Window class, which contains, among many others, a navigator object, the close, print, scroll, and moveTo methods, and a whole bunch of event handlers, such as onLoad, onClick, onKeyUp, onMouseOver, onTouchStart, and onSubmit. Use an alert to get a pop-up message in the web page, such as in todo_v2.dart:

   window.onLoad.listen( (e) =>       window.alert("I am at your disposal") );    

If your browser has tabs, each tab will open in a separate window. From the Window...