Firefox SDK Add-on with a sidebar on both the right and left at the same time
问题 I'm programming a Firefox Add-on SDK based extension. I need to use both a left and a right-side sidebar, at the same time . By default, I can display one on the left side. I've already read about changing between having the ui/sidebar on the left and the right by using the CSS: @namespace url(http://www.mozilla.org/keymaster/gat...re.is.only.xul); hbox#browser { direction: rtl !important; } hbox#browser > vbox { direction: ltr !important; } But, that seems to be something of the old-school,