Best way to add Loading indicator while loading a remote page



I’m struggling what is the best way to show a loading indicator (a spinner) while loading an external page.
for the first page it is easy. just don’t show the browserwindow yet…
But how can I do this when navigation to another (remote) page.
I have seen the event did-start-loading.
I want to have a kind of spinner running in the application menu (or so… ) so that there is an indication that the page is loading.