// 'Activity throbber' script for Firefox 60+ by Aris

Components.utils.import("resource:///modules/CustomizableUI.jsm");
var { Services } = Components.utils.import(
  "resource://gre/modules/Services.jsm",
  {}
);
var sss = Components.classes[
  "@mozilla.org/content/style-sheet-service;1"
].getService(Components.interfaces.nsIStyleSheetService);

var at_label = "Activity Throbber";

var ActivityThrobber = {
  init: function () {
    try {
      document.addEventListener("TabAttrModified", _ActivityThrobber, false);
      document.addEventListener("TabSelect", _ActivityThrobber, false);
      document.addEventListener("TabOpen", _ActivityThrobber, false);
      document.addEventListener("TabClose", _ActivityThrobber, false);
      document.addEventListener("load", _ActivityThrobber, false);

      // add or remove 'busy' tab from activity item
      function _ActivityThrobber() {
        if (gBrowser.selectedTab.hasAttribute("busy")) {
          document
            .querySelector("#activity_throbber")
            .setAttribute("busy", "true");
        } else
          document.querySelector("#activity_throbber").removeAttribute("busy");
      }

      // create a default toolbar button
      CustomizableUI.createWidget({
        id: "activity_throbber", // button id
        defaultArea: CustomizableUI.AREA_NAVBAR,
        removable: true,
        label: at_label, // button title
        tooltiptext: at_label, // tooltip title
        onCreated: function (button) {
          return button;
        },
      });

      // style button icon / embedded non-animated icon, because there is no image for then inside Fx anymore
      var uri = Services.io.newURI(
        "data:text/css;charset=utf-8," +
          encodeURIComponent(
            `#activity_throbber {
  -moz-appearance: none !important;
  list-style-image: url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAQBAMAAADt3eJSAAAAJ1BMVEUAAAC0tLS0tLSysrK0tLS0tLS0tLS1tbW0tLS6urq0tLS3t7eurq4SF2bYAAAADXRSTlMA2oILm3RnVEEF0y4TZ0HrPwAAAE5JREFUCNdjAAIjZQYISBQDU1uUA0WNvIEMR/FDOoUiQIbiCgaGLiEgY3oDAwNHJQPDtGCQQtNMBkWQKJCEM+BSMMVw7XAD4VYgLIU7AwA5fBJ3rMaMkwAAAABJRU5ErkJggg==);
  width: 16px !important;
  height: 16px !important;
}
#activity_throbber *,
#activity_throbber:hover * {
  -moz-appearance: none !important;
  opacity: 1.0 !important;
  box-shadow: unset !important;
  background: unset !important;
}
#activity_throbber[busy] {
  list-style-image: url("chrome://global/skin/media/throbber.png");
}
	`
          ),
        null,
        null
      );

      // remove old style sheet, before registering the new one
      if (sss.sheetRegistered(uri, sss.AGENT_SHEET)) {
        sss.unregisterSheet(uri, sss.AGENT_SHEET);
      }
      sss.loadAndRegisterSheet(uri, sss.AGENT_SHEET);
    } catch (e) {
      Components.utils.reportError(e);
    }
  },
};

document.addEventListener("DOMContentLoaded", ActivityThrobber.init(), false);