Bug 4240 Can't edit class path entry (1GKEPIF)
There is no way to edit an existing entry for a library on the Java Build Path project properties page (other than editing the .classpath file directly). NOTES: EG (9/22/2001 11:42:11 AM) this is particularly annoying for variables. we should have an Edit button when a variable is selected.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/wizards/buildpaths/NewVariableEntryDialog.java
private final Image IMG_FOLDER= PlatformUI.getWorkbench().getSharedImages().getImage(ISharedImages.IMG_OBJ_FOLDER);
		private final Image IMG_FILE= PlatformUI.getWorkbench().getSharedImages().getImage(ISharedImages.IMG_OBJ_FILE);
	
		public Image getImage(Object element) {
			if (element instanceof File) {
				File curr= (File) element;
				if (curr.isDirectory()) {
					return IMG_FOLDER;
				} else {
					return IMG_FILE;
				}
			}
			return null;
		}
	
		public String getText(Object element) {
			if (element instanceof File) {
				return ((File) element).getName();
			}
			return super.getText(element);
		}
	}
	
	private static class FileContentProvider implements ITreeContentProvider {