Bug 37763 Reorg: doesn't support to move an internal JAR [refactoring] [ccp] [dnd]
It should be possible to move an internal JAR to another project and have the build class path updated. feedback from thoughtworks: I couldn't find a simple way to move a jar file and have the build path automatically correct itself. I ended up moving it in the resource perspective and then manually editing the classpath file
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/packageview/SelectionTransferDragAdapter.java
public SelectionTransferDragAdapter(ISelectionProvider provider) {
		super(provider);
	}
	protected boolean isDragable(ISelection selection) {
		if (selection instanceof IStructuredSelection) {
			for (Iterator iter= ((IStructuredSelection)selection).iterator(); iter.hasNext();) {
				Object element= iter.next();
				if (element instanceof IJavaElement) {
					IPackageFragmentRoot root= (IPackageFragmentRoot)((IJavaElement)element).getAncestor(IJavaElement.PACKAGE_FRAGMENT_ROOT);
					if (root != null && root.isArchive())
						return false;
				}
			}
			return true;
		}
		return false;
	}
}