Unable to dynamically redraw the dragged cell as it moves up and down the table

[robinmacharg]

Great library, perfect drop in functionality for what I need. This is more of a feature request. I have some dynamic content - the cell number - that I'd like to have update as the cell is dragged around. Other use-cases could be imagined (background colour in an alternately-striped table etc). I'd like a method I could call from the delegate as the cell moves. I'm already reloading data in the delegate's reorderRowAt... method but this doesn't regenerate the UIImage snapshot used in dragging. A naive fix for this is to make createSnapshotViewForCell() public and call that, but I suspect that there are situations where something this simple will break. Happy to look at contributing a PR if you can suggest your preferred extension point for this. Thanks.

[adamshin]

Hey! Glad the library's been helpful for you.

Currently, the snapshot view has to be generated at the beginning of the drag-and-drop interaction. This is because the target cell isn't actually present in the tableview while the user's dragging; it's replaced with a blank 'spacer cell'. So I'm not sure if there's a simple way to accomplish what you're looking for.

Maybe you could create your own snapshot view with the same view hierarchy as the table cell, keep a reference to it in your view controller, and update it that way? You could add another TableViewReorderDelegate method, and have the reorder controller check if you're providing a custom snapshot view before it generates a UIImage snapshot. Or something like that.

If you do figure anything out, let me know. I'd welcome any contributions or improvements. The library could use a bit of work -- there's some lingering iOS 11 issues still. I've thought about a more comprehensive rewrite that relies less on UIKit behaviors... Just a matter of finding the time.