1904025 - [macOS] Tab hover preview is misplaced or missing when dragging the window to an external monitor

Status: NEW

(Firefox :: Tabbed Browser, defect, P3)

Description

[Bianca Hidecuti, Desktop Test Engineering [:bhidecuti]]

Attachment: ss showing the issue

Found in

• 128.0b5

Affected versions

• 129.0a1 (2024-06-20)
• 128.0b5

Tested platforms

• Affected platforms: MacOS 13/14
• Unaffected platforms: Windows 11

Preconditions

• ‘browser.tabs.hoverPreview.enabled’ set to ‘true’
• Have at least one external monitor connected and configured to be positioned above the main display

Steps to reproduce

1. Open a few tabs
2. Drag the browser window upwards to the external monitor, until the window appears at the bottom edge of the external monitor
3. Hover on each tab

Expected result

• Tab hover preview is correctly displayed and positioned

Actual result

• Tab hover preview is misplaced and truncated

Regression range

• Not a regression since this is reproducible on the old Nightly build from 2024-01-14 where this feature officially landed

Additional notes

• See the attached ss
• Also, the tab hover preview is not displayed when other display arrangements are configured (side by side, below) and the window is dragged to the edge of the second screen. To reproduce the issue in a side by side monitor arrangement, position the window between monitors so that only 3-7 tabs are visible
• Not reproducing when dragging the window above the edge of the external monitor
• Not reproducing on Chrome browser
• I am unable to test this on Ubuntu

Comment 1

[Chris Peterson [:cpeterson]]

This bug might get fixed by bug 1900867.

Comment 2

[Jeremy Swinarton]

Hi :bhidecuti, now that bug 1900867 has been fixed, can you see if this is still reproducing? I am unable to repro locally.

Comment 3

[Bianca Hidecuti, Desktop Test Engineering [:bhidecuti]]

Attachment: ss with the issue

(In reply to Jeremy Swinarton from comment #2)

Hi :bhidecuti, now that bug 1900867 has been fixed, can you see if this is still reproducing? I am unable to repro locally.

Hey Jeremy,
I am still able to reproduce the issue on the latest Nightly 129.0a1 (2024-07-05), using macOS 13.6 / 14.4 as described in Comment 0.

The window needs to be positioned near the bottom of the second monitor in order to reproduce it. Please let me know if I can provide more details. Thanks!

Comment 4

[Jeremy Swinarton]

Hi :bhidecuti, I was able to reproduce a variant of this issue locally using a different display. I think the key to reproducing this is that the displays need to have different pixel densities. Can you send me the screen resolution and physical size of the displays you can reproduce this with? The information given in System Settings > About > General > Displays should be sufficient.

For posterity, I can reproduce this with:

• built-in display, 16-inch, 3456x2234
• external display, 21.5-inch, 1920x1080

In my reproduction, the THP card appears huge -- about twice as big as it should be. if my suspicion is correct, the original bug should be reproducible with the reverse pixel density ratio, i.e. with an external display that has a pixel density of around 200% of the main display.

Comment 5

[Bianca Hidecuti, Desktop Test Engineering [:bhidecuti]]

(In reply to Jeremy Swinarton from comment #4)

Hi :bhidecuti, I was able to reproduce a variant of this issue locally using a different display. I think the key to reproducing this is that the displays need to have different pixel densities. Can you send me the screen resolution and physical size of the displays you can reproduce this with? The information given in System Settings > About > General > Displays should be sufficient.

For posterity, I can reproduce this with:

• built-in display, 16-inch, 3456x2234
• external display, 21.5-inch, 1920x1080

In my reproduction, the THP card appears huge -- about twice as big as it should be. if my suspicion is correct, the original bug should be reproducible with the reverse pixel density ratio, i.e. with an external display that has a pixel density of around 200% of the main display.

Hi Jeremy,
Sure. Here is the requested information:

• Built-in Retina display, 16-inch, 3072x1920
• External display (Dell), 30.5-inch, 1920x1080

I am still able to reproduce the issue as described in Comment 0, using the latest Nightly.
Hope it helps!

Comment 6

[Jeremy Swinarton]

Hi :bhidecuti, I have done some more looking into this. I am actually able to reproduce this with all elements that are implemented with a <panel>, like the app settings menu, so I have confirmed this is a deeper issue than just with THP. I have created bug1909290 to track this and I would suggest that we take this off the list of bugs blocking a green THP release, since it seems to have a much broader scope.

Comment 7

[Bogdan Maris, Desktop Test Engineering]

Responding on behalf of :bhidecuti. I think it is fair to take it out of our list of bugs that in our opinion causes to have a Yellow QA status for Fx129 based on your comment from above. We'll track this bug and bug 1909290 though for when a fix will land and see how it will impact THP.