Render only when needed

[aengelke]

As the web demo does, it would be great if only the pages that are currently in the viewport get rendered on an update. Otherwise, Atom hangs for ten seconds when updating a 100 page document.

[izuzak]

Ahhh, that's a great idea! :heart_decoration: I'm on vacation next week, but I hope I can find some time to take a stab at this. Thanks for creating an issue.

If someone else wants to make a pull request to support this -- please do!

[laughedelic]

:+1: this would be a great feature!

[X-G]

This feature is extremely helpful when opening a long pdf file such as Phd thesis.