Limiting dragging area

[svenoaks]

I'd like to be able to limit the draggable area when the popup is open. For instance, a small strip at the top of the popup will respond to dragging, but the rest of the view will not. Right now, with .popupInteractionStyle(.drag), the entire popup view is draggable.

Is there a way to limit the draggable area, either on the library side or the app side?

[LeoNatan]

Hello, can you please explain further what you are looking to do? This library uses my LNPopupFramewotk under the hood, which might have a solution. I just need to think how to integrate it with LNPopupUI.

[LeoNatan]

If I understand correctly, this is what would be useful in LNPopupController:

https://github.com/LeoNatan/LNPopupController/blob/c9683ef4da534a83cb9fe2481360a9c6ecf9b91f/LNPopupController/LNPopupController/UIViewController%2BLNPopupSupport.h#L96

Now the question is, how to design the SwiftUI API.

[iDevelopper]

Hello @LeoNatan ,

I don't think so.

@svenoaks would like to be able to limit the draggable area when the popup is open.

So I think he must be able to answer at:

gestureRecognizerShouldBegin(_:)

[LeoNatan]

It's possible to add a view and designate that for popup interaction. That sounds much more convenient to me than doing calculation in the gesture recognizer delegate.

[svenoaks]

Hi, yes it would something like designate a view in the popup as the only one for interaction. As a workaround, I was trying to block the dragging from happening by adding highPriorityGestures to some views in the popup, but without success.

I have attached a screenshot of exactly what I mean.

[LeoNatan]

Suggestions for SwiftUI API are welcome.

[svenoaks]

As an iOS noob, I'm not sure how possible or convenient it is, but could it just as simple as a View modifier that we place on one of the children of the popup? Like .popupInteractionView()

[LeoNatan]

@svenoaks That's what I was thinking too. I will give it a go, and see if can be made to work.

[LeoNatan]

Implemented in 1.2.12

[LeoNatan]

Just make sure to read the note in the API header. You should set the interaction container to be a view that is at the back of the hierarchy, to prevent issues with blocking views underneath.

[svenoaks]

Hi, thanks for doing it so quick. I can't get it to work though, it seems to either stop the interaction in the popup completely or not limit it at all depending on where I put the .popupInteractionContainer()

For example, here the entire popup is still able to be interacted with.

[LeoNatan]

Please provide a small demo project where it fails. It could be a limitation of the background modifier in SwiftUI, and so you might need to move the popup interaction container to the bottom or top of the call.

[svenoaks]

The link above is the LNPopupUI demo app with it added

[LeoNatan]

I’ll try to see what’s going on soon.

[svenoaks]

Hi, any progress on this? 🙏

[LeoNatan]

Sorry, not yet. Will look soon.

[LeoNatan]

Please test now. After my fix in 1.2.13, your example code behaves as expected.

[svenoaks]

Thank you for continuing to work on this, I know you are probably busy with other things. If you wanted some compensation for your time for continuing to perfect this feature and also #8 you can email me at the email in my profile, let me know what your hourly rate would be.

A couple things I noticed:

1. In the demo app I added a ScrollView to the player, when the ScrollView is at the top, the popup will be dragged back to the collapsed state, even though the popupInteractionContainer() on the View at the top of the screen should prevent this from happening.

2. When popupInteractionContainer() is used, the popupBar no longer responds to dragging (except on the very bottom of it for some reason, possibly it's receiving gestures from the popupInteractionContainer below it). I feel like most use cases that use popupInteractionContainer() would still want the popupBar to be draggable.

[svenoaks]

Edited the above demo app so the popupInteractionContainer() is no longer within the ScrollView to make the intention more clear.

[LeoNatan]

Regarding 1, I will not make a change. Scroll views are meant to interact with the framework. If your interaction view is inside a scroll view, it will not work as expected with the current implementation. It's a limitation with SwiftUI. Maybe will look to improve this in the future.

2 sounds like a bug. Does it reproduce in the above linked project?

[svenoaks]

Regarding 1, I will not make a change. Scroll views are meant to interact with the framework. If your interaction view is inside a scroll view, it will not work as expected with the current implementation. It's a limitation with SwiftUI. Maybe will look to improve this in the future.

2 sounds like a bug. Does it reproduce in the above linked project?

In 1, the interaction view is not inside the ScrollView, the ScrollView is below the interaction view in the VStack. Not sure if it makes a difference for what you're saying about the limitation with SwiftUI, but wanted to point that out.

Yes 2, is happening with the demo app linked above.

[LeoNatan]

I changed the implementation recently so that the view is just a hint for the system where to limit the interaction area. The gesture recognizer is not actually added to that view. The reason is that in some cases the system does not send the gestures to the interaction view. So right now, I calculate where the interaction view's frame is in relation to the topmost content view, and limit interaction to that view only. You can see why this approach wouldn't work if the interaction view is in a scroll view.

Will take a look soon.

[LeoNatan]

2 should be fixed with latest LNPopupController.