1640640 - Support taking large full page screenshots with higher device pixel ratios

Status: UNCONFIRMED

(DevTools :: General, enhancement, P3)

Description

[Frederick Zhang]

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:77.0) Gecko/20100101 Firefox/77.0

Steps to reproduce:

Open a large page, take a full page screenshot using :screenshot --fullpage --dpr 2

Actual results:

According to https://bugzilla.mozilla.org/show_bug.cgi?id=766661#c85, there is a 10000x10000 size limit currently and device pixel ratio can be reduced to 1.

Expected results:

Take a full page screenshot with dpr=2.

I tested like 4 or 5 extensions that try to take multiple screenshots and glue them together but none of them worked properly. It'd be nice if this can be supported by the built-in command. If efficiency is a concern when a user tries to take a snapshot of a really large page, perhaps we can still have a default size limit but allow users to override it? For instance:

> :screenshot --fullpage --dpr 2
Refused to take the snapshot since the dimensions of the page exceed the default 10000x10000 limit. You can specify --force to override this behaviour.
> :screenshot --fullpage --dpr 2 --force
# proceeds to take the snapshot (even if it may slow down Firefox for a few seconds)

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

Bugbug thinks this bug should belong to this component, but please revert this change in case of error.