gecko-dev/toolkit/components/extensions/ext-c-extension.js

"use strict";

this.extension = class extends ExtensionAPI {
  getAPI(context) {
    let api = {
      getURL(url) {
        return context.extension.baseURI.resolve(url);
      },

      get lastError() {
        return context.lastError;
      },

      get inIncognitoContext() {
        return context.incognito;
      },
    };

    if (context.envType === "addon_child") {
      api.getViews = function(fetchProperties) {
        let result = Cu.cloneInto([], context.cloneScope);

        for (let view of context.extension.views) {
          if (!view.active) {
            continue;
          }
          if (!context.principal.subsumes(view.principal)) {
            continue;
          }

          if (fetchProperties !== null) {
            if (fetchProperties.type !== null && view.viewType != fetchProperties.type) {
              continue;
            }

            if (fetchProperties.windowId !== null && view.windowId != fetchProperties.windowId) {
              continue;
            }

            if (fetchProperties.tabId !== null && view.tabId != fetchProperties.tabId) {
              continue;
            }
          }

          result.push(view.contentWindow);
        }

        return result;
      };
    }

    return {extension: api};
  }
};