Ionic-framework: Virtual Scroll update after scrolling stops

[danbucholtz]

Make virtual scroll update the position and displayed elements when scrolling is done.

[danbucholtz]

I am 90% done with this already, so assigning to RC.1

[AzzamAsghar]

Can you please solve virtual scrolling going to top after change in dataset in this update????virtual scrolling is a tremendous feature especially when used with infinite scroll but this scrolling problem is just rendering it useless in many cases like in News Feed.

[danbucholtz]

@AzzamAsghar,

Please file a separate issue for that problem. It won't be fixed with the change discussed in this issue.

Thanks,
Dan

[danbucholtz]

Sorry, accidentally assigned you @manucorporat.

[zakton5]

This issue mentions updating when scrolling is done, but I'm also seeing on iOS that the items do not render while a long scroll is still going. Is this being considered as well?

[Jumptidus]

rc.1 rc.2 rc.3
nothing!
I really need this..............Please

[DavidTalamona]

I just read an informative article about that problem: http://developer.telerik.com/featured/scroll-event-change-ios-8-big-deal/ - especially the part at "One caveat for Cordova developers".

Seems like it's a problem with the "old" webview used by Cordova and cannot be fixed until the "new" webview is acceptable as a replacement.
So @danbucholtz, is there anything the IONIC team could do about it? Don't think you're implementing custom scrolling, are you?
Think we all have to wait for Cordova to implement the WKWebView.

If I'm getting this right, then please add some note at the virtualScroll docs because that issue basically makes it useless for iOS.

Update:
Just found the this related IONIC blog post: http://blog.ionic.io/cordova-ios-performance-improvements-drop-in-speed-with-wkwebview/

[adamdbradley]

@DavidTalamona Yes, we've built a plugin to use WKWebView: http://blog.ionic.io/cordova-ios-performance-improvements-drop-in-speed-with-wkwebview/

And Virtual Scroll adjusts for UIWebView since it doesn't fire scroll events during inertia. I'm working on this issue now, thanks.

[adamdbradley]

@Jumptidus Can you explain more what the issue is and what you need fixed?

[Jumptidus]

we use ionic for forums. need build a long list for posts.we choose virtualscroll but when I use ion-infinite update it .virtualscroll always scroll to top..

our user love scroll scroll scroll....so have a really long list cannot use ngfor.

understand what i mean

my English is poor.sorry

[faraazc]

@mlynch @adamdbradley @jgw96 virtual scroll+infinite scroll is a basic requirement for any data driven apps. Please get this fixed as early as possible. Possibly before final release. on addition of new data in to the dataset scroll should not move to top. I tried many tweaks but could not achieve. Please help us on this. Thanks in advance

[Jumptidus]

Hi...
Will fix in rc4?
@adamdbradley

[jgw96]

Hello all! So just to clear up some confusion here this issue is about the virtual scroll updating when scrolling has stopped to make sure that the page is not left with blank space that should have elements rendered in it. The issue that you guys are asking about here with the virtual scroll scrolling back to the top when updating it with data as you are scrolling is tracked here https://github.com/driftyco/ionic/issues/6423.

[jgw96]

I am currently testing this issue (virtual scroll leaving white space and not rendering when you stop scrolling). On UiWebView, which was originally where the biggest issue was, I can confirm that it is fixed. Will post more of my findings as I test.

[jgw96]

So from my testing with an iphone 5, Nexus 6, and chrome on the desktop i can confirm that this issue is not happening on the latest release (rc4). 🎉

[jgw96]

Hello everyone! I am going to close this now as I cannot reproduce this issue in RC4, but if you still run into this issue please feel free to comment and I will happily reopen. Thanks for using Ionic!

[ionitron-bot[bot]]

Thanks for the issue! This issue is being locked to prevent comments that are not relevant to the original issue. If this is still an issue with the latest version of Ionic, please create a new issue and ensure the template is fully filled out.