Concept - Action Popup (AKA Secondary Menu, Context Menu)

Specifications

What is the definition for a popup.

Options

ActionPopup definition - similar to the Actionbar definition.
- possibly extend ActionbarDefinition / ActionbarSectionDefinition
- Cons: Could get out of sync.
In the action definition - additional flag that marks that it should show up in popup
- isCommon, isInPopup, includeInContextMenu
- see also actions availibility concept (Tobias, Sasha)

How to display it in the UI.

Could we extract a generic menu out of the actionbar that could be used in actionbar and in actionpopup? (section)

What about in cases where we need the popup - but there is no regular actionbar?

Probably define an actionbar for this case.

Parts

Invokation
Right click on workbench row invokes ActionPopup
Click on a button in FileUploadField can invoke ActionPopup - probably needs to point to which one it wants.
Shell has a method - or UIContext, so you can get it from anywhere? openActionPopup("name") (could take the name of an actionpopup or of an actionbar)
UI
- ActionPopup should float above all UI.
- ActionPopup should be positioned at mouse (and fully onscreen)
- It should go away if
  - Click on menu Item
  - or click mouse (It could display a modal curtain while it is open)
  - or timeout
  - or switch apps, or subapps, or open an Overlay, or open a shellapp,
  - Does Vaadin have concept of foccused item - could this help us know when the popup should close?
Generalize UI menu
- Actionbar becomes ActionMenu
- Css must get tuned.
- Actionbar uses ActionMenu
- Actionpopup uses ActionMenu
- ActionPopup takes an ActionMenu definition
- can be build from configuration
- can be construct manually.

Tasks

Implement a host for the ActionPopup

Shell has a server component which is the actionpopup? You can hide and show it + position it.