1910518 - Understand how Chrome calculates the dynamic toolbar height in viewport units

Status: NEW

(Core :: Layout, task)

Description

[Hiroyuki Ikezoe (:hiro)]

Attachment: t1.html

While I am working on bug 1909181, I found a weird case on Chrome. I am going to attach a couple of test cases to explain it.

Attaching file is a normal case, it's rendered as 1.0 scale, and its minimum scale is also 1.0.

The 100svh value on Chrome on my Pixel 3 is 654.18... px.
The 100lvh value on Chrome on the same device is 710.18... px.

The approximate diff is 56px.

Comment 1

[Hiroyuki Ikezoe (:hiro)]

Attachment: t2.html

This attaching file is similar to the first case in comment 0. The difference is it's rendered as 0.5 scale, thus the minimum-scale is 0.5 as well.

In this test case

The 100svh value on Chrome on my Pixel 3 is 654.18... px.
The 100lvh value on Chrome on the same device is 710.18... px.

The approximate diff is 56px. They all are same as the first test case.

That matches my mental model of viewport units.

Comment 2

[Hiroyuki Ikezoe (:hiro)]

Attachment: t3.html

This is the weird test case. It's rendered as 0.25 scale, the minimum scale is also 0.25 I believe.

The 100svh value on Chrome on my Pixel 3 is 654.18... px.
The 100lvh value on Chrome on the same device is 836.52... px.

The approximate diff is 182px. What's going on there?