1478703 - Proactively warm up layers for the next (and previous?) tab when user presses ctrl (Win/Lin) or cmd (Mac)

Status: NEW

(Firefox :: Tabbed Browser, enhancement, P5)

Description

[:Gijs (he/him)]

We do a reasonable job of using mouse interactions to cache tabs. We could do something similar for keydown on the "accel" (ctrl/cmd) key? There'd be a reasonable rate of false positives, but I'm not sure how detrimental that'd really be. Doug, thoughts?

Comment 2

[Alex Thayer [:alexical] (she/her)]

I don't think it would be too detrimental. Hard to say though. 95th percentile for TABCHILD_PAINT_TIME is 80ms, and the median is 9ms. So that's very roughly the level of work we're talking about. That doesn't sound great on a single core machine, but it sounds fine to me on a multi-core machine?

I imagine the big offenders here would be Ctrl+F, Ctrl+C/X/V, and Ctrl+Z? We could mitigate it by avoiding it if the user is focusing any kind of text input. And we could store whether the user has ever switched tabs with Ctrl+Tab before and only do this if so.

But also, I think we'd want to think about what happens after the first switch. We don't want warming the next tab to compete for resources with the tab we're trying to show right now, but I imagine users often Ctrl+Tab through multiple tabs to get where they want to go.