Replace confirmation dialogs with undo and toasts/notifications

[diegogangl]

This is a common Gnome pattern, just do the action and then let the user ctrl+z to undo. This also implies adding undo at a global scale through the app, for instance there's no undo for marking a task as done

[nekohayo]

Well, the only permanent action I can recall is deleting tasks (thus purging them from the XML data file) or deleting tags. Why would I want to undo those? If I want to delete/purge tasks, that's because I really want them gone from the file, mainly for performance / cleanliness / reliability reasons.

Closing/dismissing tasks can always be undone by reopening them, so those actions already have a way for users to revert them.

Is there an additional usecase am I forgetting?