virtual scroll and ion-refresh together cause issues on UiWebView

[ionitron-bot]

Original issue by @jgw96 on 2016-12-22T20:25:46Z

Ionic version: (check one with "x")
[ ] 1.x
[x ] 2.x

I'm submitting a ... (check one with "x")
[x ] bug report
[ ] feature request
[ ] support request => Please do not submit support requests here, use one of these channels: https://forum.ionicframework.com/ or http://ionicworldwide.herokuapp.com/

Current behavior:

If you use virtual scroll and ion-refresh together on the same page it causes lag and makes it to where virtual scroll does not actually scroll reliably. For example, on a longer list you will sometimes have to swipe on the page multiple times before it actually scrolls. This only happens on UiWebView, on Android and WkWebView it works great. Preliminary debugging shows that this is probably because of us having to use JS scrolling on UiWebView. Also, virtualScroll by itself works great on UiWebView, this issue only happens when using an ion-refresh with virtualScroll.

Expected behavior:
VirtualScroll works great with ion-refresh

Steps to reproduce:

I have made this simple repo that illustrates the issue perfectly. Just pull down that repo and run it on an iOS device.

Ionic info: (run ionic info from a terminal/cmd prompt and paste output below):

Cordova CLI: 6.4.0
Ionic Framework Version: 2.0.0-rc.4
Ionic CLI Version: 2.1.17-201612201942
Ionic App Lib Version: 2.1.7
Ionic App Scripts Version: 0.0.47
ios-deploy version: 1.8.6
ios-sim version: 5.0.8
OS: macOS Sierra
Node Version: v6.9.1
Xcode version: Xcode 8.2 Build version 8C38

[Alkasih]

good idea to move it because it is too many comment and no fix for this?

[bluesektor]

Followed this thing all the way from here.

Using ionic 4 with ion-refresher and ion-virtual-scroll, when pulling down the refresher the refresher was blank. The fix I found was to add a z-index on the ion-refresher.

<ion-refresher (ionRefresh)="doRefresh($event)" style="z-index: 999;" >

Hope that helps someone...