[BUG] CollectionView SelectionChanged event does not fire on toolkit:popup page unless held for 3 seconds, only on iOS and only with 12.2.0 update

[mccoym98]

Is there an existing issue for this?

• I have searched the existing issues

Did you read the "Reporting a bug" section on Contributing file?

• I have read the "Reporting a bug" section on Contributing file: https://github.com/CommunityToolkit/Maui/blob/main/CONTRIBUTING.md#reporting-a-bug

Current Behavior

CollectionViews within toolkit:popup windows do not fire the SelectionChanged event unless the item has been held for 3 seconds. This issue is only on iOS, not Android, and was introduced with the 12.2.0 Update. Rolling back one fixed the problem.

Expected Behavior

Immediate click recongition on CollectionView items within a toolkit:popup window as in previous versions.

Steps To Reproduce

1. Open and run solution from repository.
2. Click to open popup.
3. Clicking any popup item should immediately close the popup (within the SelectionChanged event)
4. It will on android, but you must hold 3 seconds on iOS to fire SelectionChanged

Link to public reproduction project repository

https://github.com/mccoym98/ToolkitCollectionViewBugRepro.git

Environment

- .NET MAUI CommunityToolkit: 12.2.0
- OS: iOS 14, 15 & 16
- .NET MAUI: current

Anything else?

MAUI Community Toolkit Update 12.2.0 introduced a bug into my application only when run on iOS. I use CollectionViews inside of toolkit:popups. These CollectionViews are composed of borders and other similar elements within the DataTemplate. Those all now require a solid 3-second press in order to be activated as measured by the SelectionChanged event from the CollectionView. From what I have tested, CollectionViews not being used on a popup page are unaffected. I have rolled back NuGet updates one-by-one and pinned the issue to this toolkit on the 12.2.0 version. Buttons on the popup work fine as expected. Android works fine as well. This is an iOS only issue.

[MichaelShapiro]

I haven't updated to 12.2.0 yet (still on 12.1.0) so can't confirm the above behavior and have no desire to :) But it sure sounds like the #2727 that I reported a short while back in 12.0.0 and that was since fixed. @bijington is it a regression in 12.2.0?

[bijington]

I thought we fixed this as part of the 12.2.0 release so I'm stumped

[MichaelShapiro]

I thought we fixed this as part of the 12.2.0 release so I'm stumped

It was fixed in 12.1 - I'm pretty confident of it since it works perfectly fine in my production app right now that is on 12.1.0. Now I'm afraid of upping up the toolkit 😃

[bijington]

If that is the case then I suspect the latter commits in this PR will have caused it. #2800

I'm on vacation right now but can take a look next week

[HobDev]

I am facing this issue on macOS.

[rokmeglic71]

I have tested Android (it works), iOs (does not work, or you have to hold it for 3-4 seconds), mac (@HobDev, does it work after holding for 3-4 seconds? ) does not work.

[kramer-e]

If you need a temporary workaround, create an effect that sets UITapGestureRecognizer.CancelsTouchesInView to false for all view.GestureRecognizers on attached and apply to the Popup. Then add an empty TapGestureRecognizerto the CollectionView or parent Grid.

[rokmeglic71]

@kramer-e would you be kind enough to share the code as an example?

[kramer-e]

Add to iOS platform folder:

public class AllowSimultaneousTapEffectPlatform : PlatformEffect
{
    protected override void OnAttached()
    {
        ApplyToAllSubviews(Control as UIView);
        ApplyToAllSubviews(Container as UIView);
    }

    void ApplyToAllSubviews(UIView? view)
    {
        if (view == null) return;

        if (view.GestureRecognizers != null)
        {
            foreach (var gr in view.GestureRecognizers)
            {
                if (gr is UITapGestureRecognizer tap)
                {
                    tap.CancelsTouchesInView = false;
                }
            }
        }

        foreach (var subview in view.Subviews)
        {
            ApplyToAllSubviews(subview);
        }
    }

    protected override void OnDetached() { }
}

Add to shared code:

public class AllowSimultaneousTapEffect() : RoutingEffect {}

Add to MauiProgram builder:

       builder.ConfigureEffects(effects =>
        {
#if IOS
            effects.Add<AllowSimultaneousTapEffect, AllowSimultaneousTapEffectPlatform>();
#endif
        }

Add to popup xaml:

<toolkit:Popup ... >
    <toolkit:Popup.Effects>
        <effectsnamespace:AllowSimultaneousTapEffect />
    </toolkit:Popup.Effects>
   <CollectionView ...>
      <CollectionView.GestureRecognizers>
          <TapGestureRecognizer />
       </CollectionView.GestureRecognizers>
    </CollectionView>
</toolkit:Popup>

[rokmeglic71]

@bijington Hope you had a great vacation. When you have a chance, could you please take another look at #2852? Happy to provide any extra details. Thanks!