This project demonstrates the following concepts of the CUBA platform:

• Extending functionality of screens defined in the platform.
• Using screen companions.
• Adding drag-n-drop functionality to standard CUBA UI components.

A user should be able to move users between groups in the Access Groups screen using drag-n-drop.

• Open the project in CUBA Studio, execute Run > Create database, then Run > Start application server and open the application at http://localhost:8080/app.

• Open the Administration > Access Groups screen.

• You can drag a user from the table and drop it to a group to move it to this group.

• The com/company/dd/gui/group/group-browse-ext.xml screen in the GUI module extends the group-browse.xml screen of the platform. The screen is registered in the screens.xml with the same identifier as the base screen (sec$Group.browse), so it will replace the base screen in the application.

• The group-browse-ext.xml screen descriptor defines a companion class for the web client: com.company.dd.web.group.GroupBrowseCompanion.

• The GroupBrowseExt screen controller defines the interface for the companion and delegates initialization of the drag-n-drop functionality to the companion implementation.

• The GroupBrowseCompanion.initDragAndDrop() method obtains Vaadin components from CUBA table and tree and initializes their drag-n-drop parameters.

Based on CUBA Platform 6.3.5