1526369 - Zooming in/out SOMETIMES also zooms into the entire page (UI controls of the site)

Status: NEW

(Core :: DOM: UI Events & Focus Handling, defect, P3)

Description

[Daniel Bodea [:danibodea]]

Note

• Is some cases that I could not determine exactly, when zooming in or out in the map, the entire page gets zoomed. When I mean is that not only the map is zoomed, but the UI controls of the webpage are also getting bigger or smaller.

Affected versions

• Nightly v67.0a1 (32-bit)

Affected platforms

• Windows 10 v1803 on Lenovo Yoga (table mode)

Steps to reproduce

1. Open https://www.google.com/maps
2. Zoom in/out.

Expected result

• The map is zoomed only.

Actual result

• The UI controls of the page are getting bigger/smaller.

Additional notes

• This issue does not occur on Chrome.
• This issue might be caused by returning to the page after another action has been performed or returning to the google maps tab after another tab has been in focus.

Comment 1

[Daniel Bodea [:danibodea]]

Attachment: Zooming inout SOMETIMES also zooms into the entire page UI controls of the site.mp4

Demo of the issue's reproduction.

Comment 2

[Timea Cernea [:tbabos][inactive]]

Reproduced on Lenovo Yoga C630-13Q50 with Windows 10 Home (v1803) on latest Nightly aarch64 build.

Comment 3

[Olli Pettay [:smaug][[e-mail]]]

Are there more concrete steps to reproduce here?
Since somehow we end up changing zoom level of the browser in this case, I think.

Comment 4

[Timea Cernea [:tbabos][inactive]]

Hi Olli,

We investigated a bit with Dani and got at least a possible path to debug this.
This may be happening due to a different bug. If you zoom in and out using two-finger gesture on google maps, there will be that square animation displayed right where your fingers were, right?
Now we found out that the square is misplaced. If you zoom in/out in 2 different places, the second square animation will be displayed right where you zoomed in for the first time. I also start to believe that the first one is not even displayed at all.

This explains why the UI is sometimes zoomed in. You tap the refresh button and use the zoom gesture afterward somewhere on the map. The square animation will be displayed on the refresh button or somewhere around it -> exactly on the search bar in some cases. As you also mentioned, in that case, the whole UI will be zoomed in.

To try to reproduce this:

1. refresh google maps using the refresh button
2. instantly zoom in using two fingers gesture somewhere on the map

We still don't know why it may also happen sometimes after tab switching but this is the closest repro scenario we got.
Hope it can help you somehow...

Comment 5

[Hsin-Yi Tsai (she/her) [:hsinyi]]

I find it's easier to reproduce if I use two fingers quickly to zoom in/out on gmaps "several times" before pressing the refresh button.

Comment 6

[Hsin-Yi Tsai (she/her) [:hsinyi]]

(In reply to Hsin-Yi Tsai [:hsinyi] from comment #5)

I find it's easier to reproduce if I use two fingers quickly to zoom in/out on gmaps "several times" before pressing the refresh button.

Okay, after I tried more times, my previous comment doesn't seem right ... I started to have hard time reproducing this.

Comment 7

[Daniel Bodea [:danibodea]]

I will reinvestigate as soon as possible.

Comment 8

[Daniel Bodea [:danibodea]]

I have attempted to find better steps to reproduce for this issue, but I wasn't very successful. I have one new reproduction cause idea that seems to match the behavior.
Firstly, it appears that it is now considerably harder to reproduce, probably because of the performance improvements since the bug was logged.
Secondly, I have realized that this issue only reproduces if the pinch-to-zoom action is performed exactly when the content area of the browser is white/blank. Basically just before starting to load the page, that very short time when it appears that there is no content to display.

It appears that it reproduces if the user refreshes the page, then immediately performs the pinch-to-zoom action with a reproduction rate of about 30% AND it also reproduces if the user performs one pinch-to-zoom action, then refreshes the page and performs a pinch-to-zoom action again, having a reproduction rate of about 40% (reasons unknown).

This appears to be the most probable/accurate reproduction of this issue with Firefox Nightly v67.0a1 from 2019-02-20 (aarch64 build on Lenovo Yoga).

Comment 9

[Hsin-Yi Tsai (she/her) [:hsinyi]]

Thank you for helping sorting out the reproduce steps, Daniel!
According to the comment 8, it has very low chance to reproduce it by normal user manner. I'm moving this to P3.