Turning on Reader Mode resets reading position to top of page

PurplePeopleEater

When scrolling through a web page, and then enabling reader mode, the reading position is returned to the top of the page.

It appears that reader mode and non-reader mode maintain separate reading positions. If I enable reader mode, then scroll around, when I disable reader mode, I'm returned to the original reading position. If I re-enable reader mode, I'm returned to the last reading position before leaving reader mode. When I go back and forth, the two reading positions seem to be restored and maintained separately.

Here's a video demonstratiing:

This appears on both mobile and desktop, in the most up to date Test Flight and RC builds.

I expected the reading position to remain the same between reader mode and non-reader mode.

0.99.136.2-rc

Tahoe (26)

RoxyRoxyRoxy

I think the main issue here is that the page layout is often heavily reflowed when using Reader Mode, so it's pretty hard to determine the reading position. Should it correspond to the first visible line of text? Maybe centered around the middle of the screen? Just from testing a few sites I can run across cases where neither of these would work well.
I'm not opposed to this change (I don't think anyone would be), but it's not as straightforward as it might seem. 🙂 If you have ideas on how to accomplish this please share them!

PurplePeopleEater

page layout is often heavily reflowed when using Reader Mode, so it's pretty hard to determine the reading position

Yes agree 100%, and I meant to call this out as a potential challenge.

My amateur assessment is that any best-effort strategy would be an improvement over resetting you to the top of the page. Maybe aim for somewhere in the middle of visible range of text, or maybe a 1/3 of the way down? I'm sure everyone's reading is slightly different, so where my eyes are focused and where yours are won't be the same, but an approximation probably would be fine for most use cases.

Additionally, I think attempting to emulate Safari's behavior could be instructive. I have no idea if Apple has implemented secret sauce that's not in the open source WebKit project, but even observing what Safari does could be a good starting point.

On really long-form articles that can represent 20 minutes or more of total reading, completely resetting the reading position like this can sometimes cost a minute or two trying to get reoriented. But a small shift & reorientation I think would be manageable for most users.