834360 - Make scrolling better in pdf.js

Status: RESOLVED INCOMPLETE

(Firefox for Android Graveyard :: General, defect)

Description

[James Willcox (:snorp) ([e-mail]) (he/him)]

So pdf.js uses a <div> filled with <canvas> for each page, which should in theory work out ok for scrolling/panning. But it's slow. The slowness could just be due to pdf.js redrawing sometimes while panning, but I think there may be something else going on.

Comment 1

[James Willcox (:snorp) ([e-mail]) (he/him)]

I have noticed that disabling the text layer (used for selection) seems to dramatically increase scrolling performance on desktop. You can put #textLayer=off in the url to disable that.

Comment 2

[Brad Lassey [:blassey] (use needinfo?)]

perhaps we can put a toggle button in the pdf.js UI that defaults to text selection off.

Comment 3

[BMO Automation]

We have completed our launch of our new Firefox on Android. The development of the new versions use GitHub for issue tracking. If the bug report still reproduces in a current version of [Firefox on Android nightly](https://play.google.com/store/apps/details?id=org.mozilla.fenix) an issue can be reported at the [Fenix GitHub project](https://github.com/mozilla-mobile/fenix/). If you want to discuss your report please use [Mozilla's chat](https://wiki.mozilla.org/Matrix#Connect_to_Matrix) server https://chat.mozilla.org and join the [#fenix](https://chat.mozilla.org/#/room/#fenix:mozilla.org) channel.