Right mouse click (or equivalent on single button mouse) and drag while holding the button.

Scrolling with mouse in draw.io
Let's say I want to display a login screen before going into the app's main screen

This does not work and I don't understand why:

default.js

    var p = WinJS.UI.processAll().then(function () {
           WinJS.Navigation.navigate('/pages/login.html');
    });

