Having a pop-up instead of any other type of message box will allow use to (1) have the box be stationary (z-index of 1 or more, fixed position, etc.); and (2) have ONE message box for ALL websites, which means a lot of time saved since you won't have to recreate a different box for each theme. Also, when not an error/warning message, we want to have a countdown and auto-close feature.
All the themes need to be capable of showing messages, preferably near the top, but it could also be a popup box like the default CSS offers. (Especially for long forms, we may actually want to only have popup message boxes.)
Signals like "the page was saved, published, updated..." should disappear after a few seconds (timer can be changed somewhere, ability to prevent the disappearance is a good idea too!) so that way the screen is not too crowded all the time.
In a similar way, we can allow for a bar at the bottom that appears whenever we receive a signal of some sort (i.e. someone created an account, the sky is blue, you just received a message, look over there, etc.)
This is most certainly a display Widget as defined in the
we have a version that works by showing a fixed popop at the top of the screen. The window has a Close button although clicking anywhere closes it. We could still implement a timer for messages that do not include an error.