Develop Reference

iOS Safari: Content disappearing when calling scrollIntoView()

We're trying to build a chat view in React that behaves like WhatsApp or Telegram: First, it should show 20 initial chat messages, and if users scroll up, additional messages are being loaded.
To make this happen, we remember the position of the first message on top, load more messages before it, and then scroll back to that message to keep the scroll position where it was (and thus prevent the content from jumping).
This already works perfectly on Desktop and Android browsers. But when we try it out on Safari iOS, the browser behaves pretty weird. Sometimes it jumps to the wrong position, and sometimes the whole messages disappear. They will re-appear once you scroll the page again with your finger.
Does anyone know the reason for this strange behavior and/or a solution for this? We've been searching the web for months now.
(Bonus: Any hint to a working (!) React component that allows lazy loading of content on top of a list while pertaining scroll position reliably on iOS would be highly appreciated. We tried quite a number of them, but none worked.)

Changing height of element moves element outside of viewport when page is scrolled

We got a list of cards that show a small part of a textbox. That textbox is limited in height via CSS. When a user clicks on "Details" the textboxes height is changed via javascript to the real height of the content.
The problem is, that when the viewport / window is scrolled and the cards height increases, it pushes itself out of the viewport. When the window is not scrolled at all, it works.
Please see the following video: https://monosnap.com/file/HauaJrJlkx2MBLGt3QOa5ulJMxFTnv
0:00 -> 0:08 is the desired opening / closing behavior that I want
0:09 -> 0:16 is the behavior I do not want, as the top text is moved out of the viewport.
Is there a way to keep the viewport, preferably without JS?
Edit: This happens only in Chrome (84.0.41), in Firefox and Safari it works as expected.
I can send you a link to the staging environment if necessary, please contact me via info#felixhagspiel.de

Looks it's done more logical that you want to be. As control placed in a bottom element (bad UI) better keep this control in viewport (strange that chest Crome thinks so).
So just display:flex build all this magic :)
Please look examples
https://drive.google.com/file/d/1faTDwJBQEv-V96O8-HC-8R2_hXkGzsQJ/view?usp=sharing
UPDATE: also please remove
tabindex="0"
And use button instead div to get the same logic with the keyboard navigation.
On Video last Chrome
Google Chrome is up to date
Version 84.0.4147.89 (Official Build) (64-bit)

Deadzone in iPhone 6 Plus, Safari, iOS8. Bottom area loses interactivity when tabs are visible

I'm making a webapp and want to use all the screen and avoid scrolling if possible. There will be buttons that need to be clicked in many areas of the page.
The area at the bottom of mobile safari is not clickable when the tab bar is open and I rotate to portrait and back to landscape.
I have set the body height to the same as window.innerHeight instead of 100% so that I don't have to scroll to get to buttons at the bottom.
bodyEl.style.height = window.innerHeight + 'px';
It may be the case that this area is not usable for interactive content.
Here is a demo with code:
http://plnkr.co/edit/327sUQ?p=preview
You should be able to open a preview of it on iPhone 6 Plus by clicking on the fullscreen button 'Launch the preview in a separate window'.
Update:
It definitely looks like it was a bug in iOS8, it's working as expected in iOS8.4, 9.0 & 10.2 from my simulator.

I may have found an answer to your issue, but would love to hear if you can confirm. Setting the content of your page to have the following styles:
overflow-y: scroll (allows you to scroll below the viewport, but only if necessary per the length of the content; the default value is visible)
-webkit-overflow-scrolling: touch (to smooth any scroll behavior)
in addition to your height: 100% (which forces the content to fill the viewport)
appears to force the iOS menu (tabs and address bar on top as well as nav bar on the bottom) in Safari to always appear. That way, button clicks to the top and bottom of the page are no longer "dead zones" and will actually work instead of opening up the Safari menu.

I'm searching for a solution for a similar problem - this is not an answer, but an attempt of explanation.
First of all - currently, I cannot confirm this behavior - seems like it's fixed in iOS 8.4 (12H143). Didn't know exaclty in which version I saw it the last time.
Nethertheless, I try to explain what I've found out (until we decided to not bother anymore).
The not clickable area is not always a dead zone. If you scroll up before you click, chances are high you get it working. Thus I think the (empty) standard navigation bar is there (height and behavior of the elements are similar/the same), even if it's empty (all element moved to the address bar) in landscape mode.
Btw.:
There's another (similar) problem with the iPhone 6 plus (not fixed yet).
If you have a position: fixed element on the top of a webpage, in landscape mode and only if there are two or more tabs open (and the tab bar is visible), you can click through this element (even through buttons) - as if the whole thing isn't there.

I know this question is a bit old, but since the issue still exists I thought I should share my experience...
As of now there is NO fix for the issue, but there is a workaround. The solution jennz0r provided may work for some, but I didn't like the idea of the menu bar always showing. I saw a website that had the issue solved... well it seemed to work at least. I didn't find anything in their css or js.
So what was the fix? Since the "dead zone" is 44px in height they simply made their floating bar 88px height :D Users would instinctively tap on the top/center of the button and it will almost always work at first try!
Another workaround would be to simply make the button/bar float 44px from the bottom.
"If it's stupid, but it works... it ain't stupid..." ;)

iOS visual flash when altering page length / scrollbar

http://jsbin.com/nesiside/1 (code is available http://jsbin.com/nesiside/1/edit)
If you scroll down in the document and click the "Lock/Unlock" button, an overlay with text will appear. You'll notice that the scrollbar length has been changed to accommodate the overlay height, not the original page height. Click "Unlock" in the overlay, and you return to the original page, in the previous scroll position.
System works great on desktop browsers, and on my Android phone, however, on iOS there is a rendering flash flash when the overlay is triggered or removed. Ultimately, I believe it is the fault of the scrollbar changing.
I've attempted the usual tricks to resolve iOS rendering issues (webkit-backface, transform3d), with no success.

Apparently, showing the content and hiding the overlay (or vise versa) was to much for the iPad 4 to render at once, causing the flash. This is odd because I tested it on an old Kindle and my Android phone and both are handled it fine with their slow processors.
To resolve the issue, I put the the scrollTop() method (used to return the user to the previous position on the underlying page) inside a requestAnimationFrame function. The result isn't perfect (content can be screen scrolling for a fraction of as section), but it is a much better result than an entire page flash.

Scrolling element invisible in Firefox

I have a problem with a news ticker in Firefox - the scrolling element becomes invisible when animating - and some weird behaviours are occurring:
When static, the element is displaying well, but when animating it is becoming invisible.
When mousing over the scrolling element it becomes visible, when mousing out it becomes invisible again.
When opening the "Inspector" window in Firefox, to look over the code, the element becomes visible. When closing the "Inspector" window, it becomes invisible.
Replicated the exact code in JSFiddle and the problem is not occurring when testing in Firefox.
I have looked over the code and I have made tests but I cannot find the source of this problem.
In all other browsers everything is working well, only in Firefox this weird behaviour is happening.
Edit:
It seems to be a local issue happening only on my end.
Removed links.