I was just replying to victorxstc2’s request for a feature that would allow click and drag, i.e., moving a document about in the window by clicking on it then dragging, like you can do in Adobe Reader.
In fact this option exists in Opera and can be set permanently via the Opera settings menu, by turning on “Scroll Is Pan” under “User Prefs”.
But it’s not particularly practical, because doing so makes it virtually impossible to choose text by clicking and dragging.
So I started playing around with keyboard combinations to see if click and drag could be done on the fly, that is, without changing the setting in opera:config.
And Eureka! it can!
The magic formula is: Ctrl+Alt+normal mouse click and drag the page about to your heart’s content.