1723485 - Consider moving the dynamic toolbar even if the root content height is smaller than 100% height but there's a position:fixed element whose height is over 100vh

Status: NEW

(Core :: Layout, enhancement)

Description

[Petru-Mugurel Lingurar [:petru]]

From github: https://github.com/mozilla-mobile/fenix/issues/17031.

Steps to reproduce

Go to jd.com and choose an item. (As a example, https://item.m.jd.com/product/100007080931.html?_fd=jdm&cover=jfs/t1/123363/4/6697/348525/5f058ffcEeca31b7f/fd109966191c7a06.jpg&ptag=138561.2.1) Make the address bar hidden and select item types. Touch on the x button.

Expected behavior

The address bar shouldn't show up when close button is hitted.

Actual behavior

It suddenly appears and makes the whole page move downwards. A screenshot:

Device information

Xiaomi Mi 8 SE, Android 10

• Android device: YES
• Fenix version: 83.1.0

Change performed by the Move to Bugzilla add-on.

Comment 1

[Petru-Mugurel Lingurar [:petru]]

Testing this issue in GVE and Kiwi Browser (based on Chomium but allows for a dynamic bottom toolbar) I'm seeing that indeed we are showing the toolbar while Kiwi doesn't.
Video - https://drive.google.com/file/d/1KksWM7h0r4K969xVVwBQaA-ZdG_djOJ8/view

Comment 2

[[ex-Mozilla] Agi Sferro | :agi]

This is a problem related to what Chrome thinks it's scrollable and what Gecko thinks it's scrollable. Chrome doesn't show the toolbar because it thinks the content it's scrollable (barely) when the bottom sheet is shown. IMO our behavior is better but this is a layout/webcompat problem.

Comment 3

[Hiroyuki Ikezoe (:hiro)]

Attachment: 0 height root element but a 100vh height position:fixed element

When the x is hit, the sites does set position:fixed property to the root element for some reason, so the root scroll element (the root element) is not scrollable any more, thus we consider we need to show the toolbar again.

I am not sure why the site sets the position:fixed, a wild guess I can is the site author wanted to stop scrolling the content.

Anyways, I am currently thinking re-appearing the toolbar is a right behavior in terms of layout. A question is "do we also need to move the dynamic toolbar if the root content height is smaller than 100% (i.e. totally visible) but there's a position:fixed element and its height is larger than 100vh".

Attaching file is an example of the 100vh position:fixed element. As of now Chrome doesn't move their scrollbar in this case.

Comment 4

[Karl Dubost💡 :karlcow]

P3 based it's only one site for now. But we know that this is a pain point for webdevs (as all viewport issues).
The meta bug is a P1.