1147157 - position:fixed elements break layout on orientation change

Status: RESOLVED FIXED

(Firefox for iOS :: General, defect)

Description

[Alex Gibson [:agibson]]

STR:

1.) Visit http://bradfrost.com/demo/fixed/index.html in Firefox for iPhone (portrait orientation)
2.) Observe the demo page uses a simple position:fixed header & footer.
3.) Rotate the device to landscape.

Expected results:

The fixed header/footer should resize to the width of the viewport on rotation.

Actual results:

The header/footer do not resize.

Note the layout breaks further if you rotate back to portrait again.

This does not happen in Safari for iOS.

Comment 1

[Aaron Train [:aaronmt]]

Reproducible. The demo seems to adjust correctly as soon as a scroll happens.

Comment 2

[Wesley Johnston (:wesj)]

We need to experiment with this more to see what we can do. We'll track for now, and re-evaluate later.

Comment 3

[Stephan Leroux [:sleroux]]

Attachment: PR

(Copied from Github)

So this is kind of a gross hack but it works. It looks like there's an issue with WKWebView where it doesn't invalidate it's drawing area on orientation change. However, it does invalidate it whenever the content area is scrolled (see https://github.com/WebKit/webkit/blob/master/Source/WebKit2/UIProcess/API/Cocoa/WKWebView.mm#L1430). I added a small method as an extension to WKWebView that will nudge the content area by a single pixel which forces the content area to invalidate and added this to the traitCollectionChange callback in BrowserViewController.

Comment 4

[Brian Nicholson (:bnicholson)]

Comment on attachment 8603549 [details] [review]
PR

Looks good! Left a few more questions/comments in the PR.

Comment 5

[Stefan Arentz | :st3fan | ⏰ EST | he/him]

Comment on attachment 8603549 [details] [review]
PR

Great! Do you have permissions on Github to merge this?

Comment 6

[Stephan Leroux [:sleroux]]

Yup I do. I'll go ahead and merge it

Comment 7

[Stephan Leroux [:sleroux]]

Attachment: PR

Added a hotfix that solved a bug which was caused by these changes where the toolbar was not being positioned correctly after enter the tab tray, then the browser view controller, then rotating the de

Comment 8

[Stephan Leroux [:sleroux]]

Attachment: PR

Bit quick on merging the last patch. This patch includes fixes from wes's comment.

Comment 9

[Stefan Arentz | :st3fan | ⏰ EST | he/him]

Also filed https://bugs.webkit.org/show_bug.cgi?id=144913