Question: Rather than show a confirmation dialogue when someone wants to archive a project (each row in the animation is a 'project'), I've decided to immediately archive, with the option to undo.

My question is, should this row disappear after a certain time? Or should it persist until the user visits another screen?

[![Archiving a row](https://i.stack.imgur.com/gxZEf.gif)](https://i.stack.imgur.com/gxZEf.gif)

Answer: 
I would lean towards suggesting that it should remain until the user leaves the page, or refreshes. It feels like it doesn't detract by having it there after the user performs the 'archive' action.

I'm making the assumption that the user wants to archive the project, rather than 'clean up' the list of projects - if this assumption is incorrect, perhaps a 'clear this message' option might be a good addition?
I suggest you keep the item in the list, with a notice it is archived and a button to Undo, but occupying the same height it has right now and modifying the item rather than adding an extra line. This way the user can:

* archive several projects
* decide to Undo any of those without having to change multiple times of screen
* keep the layout with the same height
* have the archived item with a different style (because right now archived/non-archived items look the same)

> 
> **Project 1**
> 
> 
> Project 2 archived. **Undo**
> 
> 
> **Project 3**
> 
> 
> **Project 4**
> 
> 
>