As shown in the last OMC PI demo, notifications of errors are displayed by WJ in a very clumsy way. At the top right of the dashboard for some messages and adjacent to the command widget when the error is related to the command. 

In both cases the solution is in an unusual position, in a too small space, for too little time, with no way for the user to explore these messages and decide when to dispose of them. This is a usability defect that may lead to big frustrations when a dashboard and a device do not work, and the developer/engineer is trying to understand why.

Some better way to display notifications/errors, to review them, to dispose of them, and/or to re-display them might be needed.

Acceptance criteria

• a notification message appears as soon as it is being generated (max delay < 1s)
• a message might tell who is the originator (a tango device? tangogql? frontend?) and the content
• messages can be very brief (1-2 words) or long (eg error messages when validating an imported dashboard)
• messages can be "unread" or "read"; there should be an explicit action by the user to set the "read" status (even a mouse click on some part of the dashboard would qualify as a user action)
• unread messages remain visible until an explicit user action
• there can be a badge-like object in the GUI that signals how many "unread" mesages are there
• there mght be the possibility for the user to exceptionally view also any "read" message (up to a certain number in the past) [g.brajnik is not sure about this - check with real users]