Story
If I work on a set of items in a workspace, I can undo my last commands. If I undo them, I can also redo them if I decided that they were actually working well for me.
If I'm unsure which command would be undone or redone and on what items it will be applied, I can use a undo/redo function to show me the name of the command and to highlight all items in the current view, which it would run on.
Description of desired behavior
Undo/redo of a workspace
As is the case with the clipboard, undo/redo belongs to the workspace-level functions. Each workspace thus has its own command history, which records which command was executed in that particular workspace on which items and what the arguments were. Two command histories of two different workspaces are separate and not merged on a higher level.
Switching workspaces
If the user switches from one workspace to another, the command history is flushed, even though the state of the workspace as such is preserved.
Undo/redo is used instantly, while you work on a set of items. If you add a folder in asset management, move a couple of images into it, then realize you actually don't need it, you could call undo multiple times. On the other hand, if you add an image in asset management, then switch to your website and add a page you intend to use the image on, but then realize you won't need either, you might call undo on the "add page", but you won't switch back to asset management and call undo there to undo the "add image" - the distance between the two tasks is just too large. You rather call "delete image" than trying to figure out, what undo would do.
So the undo/redo has a similar character as the clipboard: it is a local tool and used in a limited, temporal context.
No restrictions on undo/redo
Since the command history not only contains the command that was executed, but also records the item or items it was executed on, it is always clear what has to be undone or redone. It may be, however, that the current selected view or displayed item subset can't visualize the action. If you undo an "add image" while looking at the subset of videos, the image will be removed again and you get a notification, but the view won't show the change.
Preview of undo/redo operation
If a user clicks/taps and holds the undo or redo function, a tooltip will name the type of function as well as the name of the command to be undone or redone (e.g. "Undo: delete image" or "Redo: paste 4 items"). It will also highlight all items in the current view affected by the operation, if possible. This effect disappears again if the mouse button is released or the tap ends. Note that releasing the mouse button or ending the tap does not cause the undo or redo to be executed in this case - you have to click/tap the button again to get this behavior.