Bug 296691 Change new Groups API to Virtual Resource API
If we decide that 'virtual' is the right naming for new resources concept, I will make the following changes. Add IResource#VIRTUAL flag to use in #create methods Add IResource#isVirtual indicating that a resource is virtual Remove IResource#isGroup Remove IFolder#createGroup
bundles/org.eclipse.ui.navigator.resources/src/org/eclipse/ui/navigator/resources/ResourceDropAdapterAssistant.java
}
		IContainer destination = getActualTarget(resource);
		if (destination.getType() == IResource.ROOT) {
			return WorkbenchNavigatorPlugin
					.createErrorStatus(
							0,
							WorkbenchNavigatorMessages.DropAdapter_resourcesCanNotBeSiblings,
							null);
		}
		String message = null;
		
		if (LocalSelectionTransfer.getTransfer().isSupportedType(transferType)) {
			IResource[] selectedResources = getSelectedResources();
			
			boolean bProjectDrop = false;
			for (int iRes = 0; iRes < selectedResources.length; iRes++) {
				IResource res = selectedResources[iRes];
				if(res instanceof IProject) {
					bProjectDrop = true;
				}
			}
			if(bProjectDrop) {
				
				
				message = WorkbenchNavigatorMessages.DropAdapter_canNotDropProjectIntoProject;
			} else {
				if (selectedResources.length == 0) {
					message = WorkbenchNavigatorMessages.DropAdapter_dropOperationErrorOther;
				} else {
					CopyFilesAndFoldersOperation operation;