Bug 166015 Refactor designer actions to eclipse command framework
Eclipse command framework provide a more explicit way to manage UI actions contributions, we can take it's advantage to make our actions code more clean and maintainable.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/internal/ui/editors/schematic/actions/DeleteGroupAction.java
if ( handle.canDrop( ) )
		{
			EditPartViewer viewer = editPart.getViewer( );
			try
			{
				handle.drop( );
				stack.commit( );
			}
			catch ( SemanticException e )
			{				
				stack.rollbackAll( );
				ExceptionHandler.handle( e );
			}
			viewer.select( editPart );
		}				
		
	}
	/**
	 * Gets the activity stack of the report
	 * 
	 * @return returns the stack
	 */
	protected CommandStack getActiveCommandStack( )
	{
		return SessionHandleAdapter.getInstance( ).getCommandStack( );
	}
	
}