How to retrieve title and url of a openned com.google.gwt.user.client.Window - gwt

Question

I opened a window with com.google.gwt.user.client.Window.open()
How to retrieve the title and URL of this new window after navigating in it ?
After openned a new window with "http://www.google.com" and searching "Stackoverflow" the title become "Stackoverflow - Google Search" and the URL change to "http://www.google.com/&q=stackoverflow"
I would like to retrieve these two informations in the parent window.
How do I do it with GWT ?
Example :
private void myMethod() {
Window.open("http://google.com", "Google")
// ... searching "Stackoverflow"
Button b1 = new Button(getTitleOfPopupWindow()); // Stackoverflow - Google Search
Button b2 = new Button(getUrlOfPopupWindow()); // http://www.google.com/&q=stackoverflow
}

Answer 1

Once you open a new window, it becomes a totally different window that your app cannot access - unless you have total control over its contents (i.e. it's on your domain). It would be a huge security and privacy hole if an app in one browser window/tab had access to the information in all the other windows/tabs.
You can let your users open an iFrame within your app and see where they navigate within that iFrame, if your users don't mind it.
If you have a total control over the new window, then you can insert a script in the child page to call the parent page using Window.opener. However, it looks like this is not your use case.