GWT RootPanel is the starting or the top most panel to which all other Widgets are attached. To access the root panel in the application, we can use this syntax: RootPanel.get().
This panel consists of html pages. Root panel returns the singleton value that binds the GWT application. For control modification in web-app we can change the syntax as follows: RootPanel.get(String argument).
GWT RootPanel Class Declaration
Let's see the declaration of com.google.gwt.user.client.ui.RootPanel
GWT RootPanel methods
GWT RootPanel Example