Description
A web page might request various dialogs, i.e.
- a color picker dialog
- a file selector dialog
- JavaScript Alert
- JavaScript Prompt
- User credentials for authentication (also used for proxies)
For Qt WebEngine Widgets these are QDialog based, for Qt WebEngine it's either Qt Quick Controls 1, Qt Quick Controls 2 (new in 5.8) or custom (new in 5.8). Similar things are true for context menu's.
This, and how to change them, should be listed in http://doc.qt.io/qt-5/qtwebengine-features.html .