What's the best practice for drag and drop feature with observe?

[Joshua7054]

Hello, I was trying to implement drag and drop feature with observe tools in uikit-navigation.

but I faced with unwanted thread hopping, and found the root cause of hopping(link). It leads to unnatural animations.

Can you let me know the best practice of drag and dropping? or should I make a patch that prevent thread hopping when update occured in mainThread?

[mbrandonw]

Hi @Joshua7054, the thread hop is unfortunately required because the onChange trailing closure of withObservationTracking is called in the willSet of mutating a value, not the didSet.

Can you provide a minimal project that demonstrates the problem you are seeing so that we can take a look?

[Joshua7054]

DragNDropExample.zip

Thank you for reply @mbrandonw ! I made small example for this. and here's the demo video.

dragndrop.mp4