1878038 - Missing content in the preview thumbnail if using Firefox in a wide window

Status: VERIFIED FIXED

(Firefox :: Tabbed Browser, defect, P2)

Description

[Bogdan Maris, Desktop Test Engineering [OOO until 14th April]]]

Attachment: Screenshot showing the issue

Found in

• Latest Nightly 124.0a1

Affected versions

• Latest Nightly 124.0a1

Tested platforms

• Affected platforms: MacOS 13.6, Windows 11, Ubuntu 22.04
• Unaffected platforms: none

Preconditions

• Have the Tab Hover feature active with browser.tabs.cardPreview.enabled as true in about:config

Steps to reproduce

1. Have the max possible width to the browser
2. Open two websites in two different tabs and a new blank tab (about:newtab) that has shortcuts and pocket content (for a more easy way to reproduce)
3. Focus any website and hover over the about:newtab page.

Expected result

• The content of the page (newtab) is correctly displayed in the preview.

Actual result

• A large area of the preview is empty (depending on how much wider the browser is). If using a extra wide monitor the content of the page could be just some blank area and probably only a glimpse of the Shortcuts.

Regression range

• Not a regression since this is reproducible on old Nightly build from 2024-01-13 where this feature officially landed.

Additional notes

• I noticed that Chrome does include the center of the page as their preview, having the content in the preview always displayed.

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

:bmaris, if you think that's a regression, could you try to find a regression range using for example mozregression?

Comment 2

[Bogdan Maris, Desktop Test Engineering [OOO until 14th April]]]

This does prevent the content of the preview to be shown in RTL builds as well.

Comment 4

[:Gijs (he/him)]

(In reply to Bogdan Maris, Desktop QA from comment #2)

This does prevent the content of the preview to be shown in RTL builds as well.

Can you clarify? Are the previews blank in RTL? Is this still the case?

Comment 5

[Bogdan Maris, Desktop Test Engineering [OOO until 14th April]]]

(In reply to :Gijs (he/him) from comment #4)

(In reply to Bogdan Maris, Desktop QA from comment #2)

This does prevent the content of the preview to be shown in RTL builds as well.

Can you clarify? Are the previews blank in RTL? Is this still the case?

Sure, so this is the same issue as in bug 1888919 and also can impact the RTL builds (bug 1877837) because we don't focus on showing the content in the tab preview in certain situations:

• If a page has the content in the middle of the page and has lots of extra space on the extremities like we do in about:newtab (or Facebook, Instagram etc), having a wide monitor will increase the "no content area" from extremities (left/right side). At this time when we take a screenshot of the page to display in the tab hover we do so from the top left side of the page and not focus on the content, thus we end up displaying the "no content area" more than the actual content of it (as in the attachment).
• In the RTL case it would work the same since we again take the image of a website from the left side and could end up in showing no content areas, as shown in bug 1877837 with about:preference page.

People using wide monitors (or those having Firefox stretched on multiple monitors) will be most affected by this, of course depending on the webpages since not all have their content centered in the page. In Chrome I noticed that they always focus on showing the content of the webpage no matter if the content is in the right side or centered or from the left side. I hope I clarified a bit, let me know if there is anything I can help with further on.
And yeah in the latest Nightly 127.0a1 this is still an issue for both RTL and LTR builds.

Comment 6

[DJ (:dwalker) (on PTO until Apr 7)]

Attachment: Bug 1878038 - show entire viewport in tab preview. r?emilio

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/fddf17061e79
show entire viewport in tab preview. r=emilio,tabbrowser-reviewers,mconley

Comment 8

[DJ (:dwalker) (on PTO until Apr 7)]

Attachment: Bug 1878038 - show entire viewport in tab preview. r?emilio

Original Revision: https://phabricator.services.mozilla.com/D212709

Comment 9

[Phabricator Automation]

beta Uplift Approval Request

• User impact if declined: users may experience cropped screenshots in tab preview
• Code covered by automated testing: yes
• Fix verified in Nightly: no
• Needs manual QE test: yes
• Steps to reproduce for manual QE testing: with browser.tabs.hoverPreview enabled, observe that a tab's preview screenshot shows the entire viewport and matches the aspect ratio of the content area
• Risk associated with taking this patch: low
• Explanation of risk level: new PageThumbs behavior is only used by tab-hover-preview and is covered by automated testing
• String changes made/needed: none
• Is Android affected?: no

Comment 10

[pstanciu]

https://hg.mozilla.org/mozilla-central/rev/fddf17061e79

Comment 11

[Ryan VanderMeulen [:RyanVM]]

This feature isn't enabled by default for 128, so why does it need uplift to Beta?

Comment 12

[Bogdan Maris, Desktop Test Engineering [OOO until 14th April]]]

Attachment: Browser stretch.gif

This looks mostly fixed using latest Nightly 129.0a1 build, unfortunately if I am using 2 screens and I stretch the browser from one screen to the other the image will shrink and the content shown in the preview is very tiny (depending on how much the window stretches). Before this fix the image was not stretched at all.

Both screens have 1920x1080 resolution. Do you want me to log a new issue for this or just reopen this one?

Comment 13

[Pulsebot]

https://hg.mozilla.org/releases/mozilla-beta/rev/98a4c24f9625

Comment 14

[DJ (:dwalker) (on PTO until Apr 7)]

(In reply to Bogdan Maris, Desktop QA from comment #12)

Created attachment 9408844 [details]
Browser stretch.gif

This looks mostly fixed using latest Nightly 129.0a1 build, unfortunately if I am using 2 screens and I stretch the browser from one screen to the other the image will shrink and the content shown in the preview is very tiny (depending on how much the window stretches). Before this fix the image was not stretched at all.

Both screens have 1920x1080 resolution. Do you want me to log a new issue for this or just reopen this one?

This is expected. The preview will match the aspect ratio while constraining the width to the 280px panel size. This will mean that the preview can look strange at extreme aspect ratios.

Comment 15

[Bogdan Maris, Desktop Test Engineering [OOO until 14th April]]]

(In reply to DJ (:dwalker) from comment #14)

(In reply to Bogdan Maris, Desktop QA from comment #12)

Created attachment 9408844 [details]
Browser stretch.gif

This looks mostly fixed using latest Nightly 129.0a1 build, unfortunately if I am using 2 screens and I stretch the browser from one screen to the other the image will shrink and the content shown in the preview is very tiny (depending on how much the window stretches). Before this fix the image was not stretched at all.

Both screens have 1920x1080 resolution. Do you want me to log a new issue for this or just reopen this one?

This is expected. The preview will match the aspect ratio while constraining the width to the 280px panel size. This will mean that the preview can look strange at extreme aspect ratios.

Thanks, I did log an enhancement in bug 1904932 just because I saw that Chrome handles this way better, their content is barely shrinking in the same scenario. Will go ahead and close this one as verified fixed and if we ever choose to address this we have a bug now where we can do that.