Bug 5699 Add ResourceTransfer to packages view
The packages view should add the ResoruceTransfer as a drag source to its list of transfers
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/packageview/PackageExplorerPart.java
private void addOpenWithMenu(IMenuManager menu, IStructuredSelection selection) {
		
		
		if (selection.size() != 1)
			return;
		IAdaptable element= (IAdaptable)selection.getFirstElement();
		Object resource= element.getAdapter(IResource.class);
		if (!(resource instanceof IFile))
			return; 
		
		MenuManager submenu= new MenuManager(PackagesMessages.getString("PackageExplorer.openWith")); 
		submenu.add(new OpenWithMenu(getSite().getPage(), (IFile) resource));
		
		menu.appendToGroup(IContextMenuConstants.GROUP_OPEN, submenu);
	}
	
	private boolean isSelectionOfType(ISelection s, Class clazz, boolean considerUnderlyingResource) {
		if (! (s instanceof IStructuredSelection) || s.isEmpty())
			return false;
		
		IStructuredSelection selection= (IStructuredSelection)s;
		Iterator iter= selection.iterator();
		while (iter.hasNext()) {
			Object o= iter.next();
			if (clazz.isInstance(o))
				return true;
			if (considerUnderlyingResource) {
				if (! (o instanceof IJavaElement))
					return false;