1390040 - Show site information menu sizing

Status: NEW

(Firefox :: Site Identity, defect, P3)

Description

[jackjen]

Attachment: Short video showing the issue

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.12; rv:57.0) Gecko/20100101 Firefox/57.0
Build ID: 20170813183258

Steps to reproduce:

Close Firefox
Open Firefox
On any new tab, click on the show site info drop down menu


Actual results:

Menu drop down fades in, then resizes to fit the content (noticeably in the Permissions sections). Subsequent clicks on the menu don't have the issue.


Expected results:

Menu drop down should be the right size before starting to fade in.

Comment 1

[Johann Hofmann [:johannh]]

I've encountered this on and off as well, but didn't get around to filing a bug. Thanks for doing that! The resizing is really annoying and looks slow.

Paolo, do you have any hint on what might be going on here?

Comment 2

[:Gijs (out for now; he/him)]

Pretty sure this is because the "You haven't granted this site permissions" line wraps, so this is some variant of bug 1293242, for which we have a workaround in place in JS (that causes sync reflows) - look for descriptionHeightWorkaround in the code. I don't think we can reliably run it any earlier, but Paolo would know for sure.

Comment 3

[:Paolo Amadini]

Correct, the issue here is that we have to display the panel before we can measure the elements inside descriptionHeightWorkaround, even if we run the function itself synchronously. This means there is really no workaround for this bug until we fix the platform issue in bug 1293242, or make fundamental changes to how panels work so that we can do multiple asynchronous layouts before they are displayed. Both routes seem quite complicated to achieve.

Comment 4

[:Paolo Amadini]

After bug 1420939 and bug 1434883 are fixed, it should be possible to apply the descriptionHeightWorkaround to the main view as well.

This may require using the main browser window rather than the panel to prepare the view off-screen, making sure that styling is consistent between the two.

Comment 5

[:Gijs (out for now; he/him)]

Did this get fixed in bug 1437811?

Comment 6

[:Paolo Amadini]

I expect this issue to be still there. We now have the capability to fix this by doing an off-screen layout of the main view in the browser window before opening the panel, however I'm not sure it's worth the effort just for this case, given the low impact.

There is work ongoing for replacing XUL layout with flexbox layout, and hopefully the description height workaround will become unneeded at that point.