638944 - Checkerboarding when changing Tabs

Status: RESOLVED WONTFIX

(Firefox for Android Graveyard :: General, defect, P1)

Description

[Thomas Arend [:tarend]]

(1) load at least two tabs with content (internal pages don't show this behavior)
(2) switch between tabs

Result: you see a full-screen checkerboard pattern with every tab switch
Expected: smooth tab switching, no checkerboarding

Comment 1

[Matt Brubeck (:mbrubeck)]

We intentionally discard the displayport for background tabs, to save memory (bug 589337).  This is a trade-off; if we keep the rendered image cached, then we can display it faster on switching, but it will use more memory.

As a compromise, it might be reasonable to keep the most recent 1 or 2 tabs cached, and discard background tabs only if there are more than that.

Comment 2

[Thomas Arend [:tarend]]

But that would mean that we checkerboard as soon as you have more than 2 tabs? 
Say I am viewing tab1 and tap on tab2, could we somehow load tab2 in a cache and switch to it once it is completely loaded? Or would that seem like a big delay from the tap to showing the tab content?

Comment 3

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

(In reply to comment #1)
> We intentionally discard the displayport for background tabs, to save memory
> (bug 589337).  This is a trade-off; if we keep the rendered image cached, then
> we can display it faster on switching, but it will use more memory.
> 
> As a compromise, it might be reasonable to keep the most recent 1 or 2 tabs
> cached, and discard background tabs only if there are more than that.

I don't think that's a reasonable compromise, even just holding one extra tab adds a lot of memory.

If this we decide this is a problem we want to fix (and I don't think it is), we should just not switch tabs until the new tab is rendered. It'll make switching tabs "feel" slower though, so we'll have to do some magic transition effect to combat that.

Regardless, this is not something I think we should be addressing this late in the game.

Comment 4

[BMO Automation]

Closing all opened bug in a graveyard component