Question

Setting any of

document.getElementById('PopupAutoCompleteRichResult').setAttribute('hidden', true)                                         
document.getElementById('PopupAutoCompleteRichResult').hidden = true
document.getElementById('PopupAutoCompleteRichResult').setAttribute('style', 'display: none;');`

hides the AutoComplete Popup.

But how do I show it again? Neither display: -moz-popup nor hidden = false works!

Answer 1

I’m also unable to get the AutoComplete Popup back after hiding it. But depending on your specific requirement, another possible solution is to simply disable/enable the bar through the preferences. Here’s a very simple proof-of concept I wrote that toggles availability of the bar every 10 seconds:

window.addEventListener("load", function(e) {
    var prefs = Components.classes["@mozilla.org/preferences-service;1"]
                    .getService(Components.interfaces.nsIPrefService)
                    .getBranch("browser.urlbar.autocomplete.");
    window.setInterval(function() {
        prefs.setBoolPref("enabled", !prefs.getBoolPref("enabled"));
    }, 10000);
}, false);