gecko-dev/browser/components/preferences/experimental.js

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this file,
 * You can obtain one at http://mozilla.org/MPL/2.0/. */

/* import-globals-from preferences.js */

var { FeatureGate } = ChromeUtils.import(
  "resource://featuregates/FeatureGate.jsm"
);

var gExperimentalPane = {
  inited: false,
  _template: null,
  _featureGatesContainer: null,
  _boundRestartObserver: null,
  _observedPrefs: [],
  _shouldPromptForRestart: true,

  _featureGatePrefTypeToPrefServiceType(featureGatePrefType) {
    if (featureGatePrefType != "boolean") {
      throw new Error("Only boolean FeatureGates are supported");
    }
    return "bool";
  },

  async _observeRestart(aSubject, aTopic, aData) {
    if (!this._shouldPromptForRestart) {
      return;
    }
    let prefValue = Services.prefs.getBoolPref(aData);
    let buttonIndex = await confirmRestartPrompt(prefValue, 1, true, false);
    if (buttonIndex == CONFIRM_RESTART_PROMPT_RESTART_NOW) {
      Services.startup.quit(
        Ci.nsIAppStartup.eAttemptQuit | Ci.nsIAppStartup.eRestart
      );
      return;
    }
    this._shouldPromptForRestart = false;
    Services.prefs.setBoolPref(aData, !prefValue);
    this._shouldPromptForRestart = true;
  },

  addPrefObserver(name, fn) {
    this._observedPrefs.push({ name, fn });
    Services.prefs.addObserver(name, fn);
  },

  removePrefObservers() {
    for (let { name, fn } of this._observedPrefs) {
      Services.prefs.removeObserver(name, fn);
    }
    this._observedPrefs = [];
  },

  async _sortFeatures(features) {
    // Sort the features alphabetically by their title
    let titles = await document.l10n.formatMessages(
      features.map(f => {
        return { id: f.title };
      })
    );
    titles = titles.map((title, index) => [title.attributes[0].value, index]);
    titles.sort((a, b) => a[0].toLowerCase().localeCompare(b[0].toLowerCase()));
    // Get the features in order of sorted titles.
    return titles.map(([, index]) => features[index]);
  },

  async init() {
    if (this.inited) {
      return;
    }
    this.inited = true;

    let searchParams = new URLSearchParams(document.documentURIObject.query);
    let definitionsUrl = searchParams.get("definitionsUrl");
    let features = await FeatureGate.all(definitionsUrl);
    features = features.filter(f => f.isPublic);
    let shouldHide = !features.length;
    document.getElementById("category-experimental").hidden = shouldHide;
    // Cache the visibility so we can show it quicker in subsequent loads.
    Services.prefs.setBoolPref(
      "browser.preferences.experimental.hidden",
      shouldHide
    );
    if (shouldHide) {
      // Remove the 'experimental' category if there are no available features
      document.getElementById("firefoxExperimentalCategory").remove();
      if (
        document.getElementById("categories").selectedItem?.id ==
        "category-experimental"
      ) {
        // Leave the 'experimental' category if there are no available features
        gotoPref("general");
        return;
      }
    }

    features = await this._sortFeatures(features);

    window.addEventListener("unload", () => this.removePrefObservers());
    this._template = document.getElementById("template-featureGate");
    this._featureGatesContainer = document.getElementById(
      "pane-experimental-featureGates"
    );
    this._boundRestartObserver = this._observeRestart.bind(this);
    let frag = document.createDocumentFragment();
    for (let feature of features) {
      if (Preferences.get(feature.preference)) {
        console.error(
          "Preference control already exists for experimental feature '" +
            feature.id +
            "' with preference '" +
            feature.preference +
            "'"
        );
        continue;
      }
      if (feature.restartRequired) {
        this.addPrefObserver(feature.preference, this._boundRestartObserver);
      }
      let template = this._template.content.cloneNode(true);
      let description = template.querySelector(".featureGateDescription");
      description.id = feature.id + "-description";
      let descriptionLinks = feature.descriptionLinks || {};
      for (let [key, value] of Object.entries(descriptionLinks)) {
        let link = document.createElement("a");
        link.setAttribute("data-l10n-name", key);
        link.setAttribute("href", value);
        link.setAttribute("target", "_blank");
        description.append(link);
      }
      document.l10n.setAttributes(description, feature.description);
      let checkbox = template.querySelector(".featureGateCheckbox");
      checkbox.setAttribute("preference", feature.preference);
      checkbox.id = feature.id;
      checkbox.setAttribute("aria-describedby", description.id);
      document.l10n.setAttributes(checkbox, feature.title);
      frag.appendChild(template);
      let preference = Preferences.add({
        id: feature.preference,
        type: gExperimentalPane._featureGatePrefTypeToPrefServiceType(
          feature.type
        ),
      });
      preference.setElementValue(checkbox);
    }
    this._featureGatesContainer.appendChild(frag);
    Preferences.updateAllElements();
  },
};