gecko-dev/devtools/shim/devtools-startup.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/. */

/**
 * This XPCOM component is loaded very early.
 * Be careful to lazy load dependencies as much as possible.
 *
 * It manages all the possible entry points for DevTools:
 * - Handles command line arguments like -jsconsole,
 * - Register all key shortcuts,
 * - Listen for "Web Developer" system menu opening, under "Tools",
 * - Inject the wrench icon in toolbar customization, which is used
 *   by the "Web Developer" list displayed in the hamburger menu,
 * - Register the JSON Viewer protocol handler.
 *
 * Only once any of these entry point is fired, this module ensures starting
 * core modules like 'devtools-browser.js' that hooks the browser windows
 * and ensure setting up tools.
 **/

"use strict";

const kDebuggerPrefs = [
  "devtools.debugger.remote-enabled",
  "devtools.chrome.enabled"
];

// If devtools.toolbar.visible is set to true, the developer toolbar should appear on
// startup.
const TOOLBAR_VISIBLE_PREF = "devtools.toolbar.visible";

const DEVTOOLS_ENABLED_PREF = "devtools.enabled";

const { XPCOMUtils } = ChromeUtils.import("resource://gre/modules/XPCOMUtils.jsm", {});
ChromeUtils.defineModuleGetter(this, "Services",
                               "resource://gre/modules/Services.jsm");
ChromeUtils.defineModuleGetter(this, "AppConstants",
                               "resource://gre/modules/AppConstants.jsm");
ChromeUtils.defineModuleGetter(this, "CustomizableUI",
                               "resource:///modules/CustomizableUI.jsm");
ChromeUtils.defineModuleGetter(this, "CustomizableWidgets",
                               "resource:///modules/CustomizableWidgets.jsm");

XPCOMUtils.defineLazyGetter(this, "StartupBundle", function () {
  const url = "chrome://devtools-shim/locale/startup.properties";
  return Services.strings.createBundle(url);
});

XPCOMUtils.defineLazyGetter(this, "KeyShortcutsBundle", function () {
  const url = "chrome://devtools-shim/locale/key-shortcuts.properties";
  return Services.strings.createBundle(url);
});

XPCOMUtils.defineLazyGetter(this, "KeyShortcuts", function () {
  const isMac = AppConstants.platform == "macosx";

  // Common modifier shared by most key shortcuts
  const modifiers = isMac ? "accel,alt" : "accel,shift";

  // List of all key shortcuts triggering installation UI
  // `id` should match tool's id from client/definitions.js
  return [
    // The following keys are also registered in /client/menus.js
    // And should be synced.

    // Both are toggling the toolbox on the last selected panel
    // or the default one.
    {
      id: "toggleToolbox",
      shortcut: KeyShortcutsBundle.GetStringFromName("toggleToolbox.commandkey"),
      modifiers
    },
    // All locales are using F12
    {
      id: "toggleToolboxF12",
      shortcut: KeyShortcutsBundle.GetStringFromName("toggleToolboxF12.commandkey"),
      modifiers: "" // F12 is the only one without modifiers
    },
    // Toggle the visibility of the Developer Toolbar (=gcli)
    {
      id: "toggleToolbar",
      shortcut: KeyShortcutsBundle.GetStringFromName("toggleToolbar.commandkey"),
      modifiers: "shift"
    },
    // Open WebIDE window
    {
      id: "webide",
      shortcut: KeyShortcutsBundle.GetStringFromName("webide.commandkey"),
      modifiers: "shift"
    },
    // Open the Browser Toolbox
    {
      id: "browserToolbox",
      shortcut: KeyShortcutsBundle.GetStringFromName("browserToolbox.commandkey"),
      modifiers: "accel,alt,shift"
    },
    // Open the Browser Console
    {
      id: "browserConsole",
      shortcut: KeyShortcutsBundle.GetStringFromName("browserConsole.commandkey"),
      modifiers: "accel,shift"
    },
    // Toggle the Responsive Design Mode
    {
      id: "responsiveDesignMode",
      shortcut: KeyShortcutsBundle.GetStringFromName("responsiveDesignMode.commandkey"),
      modifiers
    },
    // Open ScratchPad window
    {
      id: "scratchpad",
      shortcut: KeyShortcutsBundle.GetStringFromName("scratchpad.commandkey"),
      modifiers: "shift"
    },

    // The following keys are also registered in /client/definitions.js
    // and should be synced.

    // Key for opening the Inspector
    {
      toolId: "inspector",
      shortcut: KeyShortcutsBundle.GetStringFromName("inspector.commandkey"),
      modifiers
    },
    // Key for opening the Web Console
    {
      toolId: "webconsole",
      shortcut: KeyShortcutsBundle.GetStringFromName("webconsole.commandkey"),
      modifiers
    },
    // Key for opening the Debugger
    {
      toolId: "jsdebugger",
      shortcut: KeyShortcutsBundle.GetStringFromName("debugger.commandkey"),
      modifiers
    },
    // Key for opening the Network Monitor
    {
      toolId: "netmonitor",
      shortcut: KeyShortcutsBundle.GetStringFromName("netmonitor.commandkey"),
      modifiers
    },
    // Key for opening the Style Editor
    {
      toolId: "styleeditor",
      shortcut: KeyShortcutsBundle.GetStringFromName("styleeditor.commandkey"),
      modifiers: "shift"
    },
    // Key for opening the Performance Panel
    {
      toolId: "performance",
      shortcut: KeyShortcutsBundle.GetStringFromName("performance.commandkey"),
      modifiers: "shift"
    },
    // Key for opening the Storage Panel
    {
      toolId: "storage",
      shortcut: KeyShortcutsBundle.GetStringFromName("storage.commandkey"),
      modifiers: "shift"
    },
    // Key for opening the DOM Panel
    {
      toolId: "dom",
      shortcut: KeyShortcutsBundle.GetStringFromName("dom.commandkey"),
      modifiers
    },
  ];
});

function DevToolsStartup() {
  this.onEnabledPrefChanged = this.onEnabledPrefChanged.bind(this);
  this.onWindowReady = this.onWindowReady.bind(this);
}

DevToolsStartup.prototype = {
  /**
   * Boolean flag to check if DevTools have been already initialized or not.
   * By initialized, we mean that its main modules are loaded.
   */
  initialized: false,

  /**
   * Boolean flag to check if the devtools initialization was already sent to telemetry.
   * We only want to record one devtools entry point per Firefox run, but we are not
   * interested in all the entry points (e.g. devtools.toolbar.visible).
   */
  recorded: false,

  /**
   * Flag that indicates if the developer toggle was already added to customizableUI.
   */
  developerToggleCreated: false,

  handle: function (cmdLine) {
    let consoleFlag = cmdLine.handleFlag("jsconsole", false);
    let debuggerFlag = cmdLine.handleFlag("jsdebugger", false);
    let devtoolsFlag = cmdLine.handleFlag("devtools", false);

    // handle() can be called after browser startup (e.g. opening links from other apps).
    let isInitialLaunch = cmdLine.state == Ci.nsICommandLine.STATE_INITIAL_LAUNCH;
    if (isInitialLaunch) {
      // Execute only on first launch of this browser instance.
      let hasDevToolsFlag = consoleFlag || devtoolsFlag || debuggerFlag;
      this.setupEnabledPref(hasDevToolsFlag);

      // Store devtoolsFlag to check it later in onWindowReady.
      this.devtoolsFlag = devtoolsFlag;
      // Only top level Firefox Windows fire a browser-delayed-startup-finished event
      Services.obs.addObserver(this.onWindowReady, "browser-delayed-startup-finished");

      if (AppConstants.MOZ_DEV_EDITION) {
        // On DevEdition, the developer toggle is displayed by default in the navbar area
        // and should be created before the first paint.
        this.hookDeveloperToggle();
      }

      // Update menu items when devtools.enabled changes.
      Services.prefs.addObserver(DEVTOOLS_ENABLED_PREF, this.onEnabledPrefChanged);
    }

    if (consoleFlag) {
      this.handleConsoleFlag(cmdLine);
    }
    if (debuggerFlag) {
      this.handleDebuggerFlag(cmdLine);
    }

    let debuggerServerFlag;
    try {
      debuggerServerFlag =
        cmdLine.handleFlagWithParam("start-debugger-server", false);
    } catch (e) {
      // We get an error if the option is given but not followed by a value.
      // By catching and trying again, the value is effectively optional.
      debuggerServerFlag = cmdLine.handleFlag("start-debugger-server", false);
    }
    if (debuggerServerFlag) {
      this.handleDebuggerServerFlag(cmdLine, debuggerServerFlag);
    }
  },

  /**
   * Called when receiving the "browser-delayed-startup-finished" event for a new
   * top-level window.
   */
  onWindowReady(window) {
    this.hookWindow(window);

    if (Services.prefs.getBoolPref(TOOLBAR_VISIBLE_PREF, false)) {
      // Loading devtools-browser will open the developer toolbar by also checking this
      // pref.
      this.initDevTools();
    }

    // This listener is called for all Firefox windows, but we want to execute some code
    // only once.
    if (!this._firstWindowReadyReceived) {
      this.onFirstWindowReady(window);
      this._firstWindowReadyReceived = true;
    }

    JsonView.initialize();
  },

  onFirstWindowReady(window) {
    if (this.devtoolsFlag) {
      this.handleDevToolsFlag(window);
    }

    // Wait until we get a window before sending a ping to telemetry to avoid slowing down
    // the startup phase.
    this.pingOnboardingTelemetry();
  },

  /**
   * Check if the user is being flagged as DevTools users or not. This probe should only
   * be logged once per profile.
   */
  pingOnboardingTelemetry() {
    // Only ping telemetry once per profile.
    let alreadyLoggedPref = "devtools.onboarding.telemetry.logged";
    if (Services.prefs.getBoolPref(alreadyLoggedPref)) {
      return;
    }

    let scalarId = "devtools.onboarding.is_devtools_user";
    Services.telemetry.scalarSet(scalarId, this.isDevToolsUser());
    Services.prefs.setBoolPref(alreadyLoggedPref, true);
  },

  /**
   * Register listeners to all possible entry points for Developer Tools.
   * But instead of implementing the actual actions, defer to DevTools codebase.
   * In most cases, it only needs to call this.initDevTools which handles the rest.
   * We do that to prevent loading any DevTools module until the user intent to use them.
   */
  hookWindow(window) {
    // Key Shortcuts need to be added on all the created windows.
    this.hookKeyShortcuts(window);

    // In some situations (e.g. starting Firefox with --jsconsole) DevTools will be
    // initialized before the first browser-delayed-startup-finished event is received.
    // We use a dedicated flag because we still need to hook the developer toggle.
    this.hookDeveloperToggle();

    // The developer menu hook only needs to be added if devtools have not been
    // initialized yet.
    if (!this.initialized) {
      this.hookWebDeveloperMenu(window);
    }

    this.createDevToolsEnableMenuItem(window);
    this.updateDevToolsMenuItems(window);
  },

  /**
   * Dynamically register a wrench icon in the customization menu.
   * You can use this button by right clicking on Firefox toolbar
   * and dragging it from the customization panel to the toolbar.
   * (i.e. this isn't displayed by default to users!)
   *
   * _But_, the "Web Developer" entry in the hamburger menu (the menu with
   * 3 horizontal lines), is using this "developer-button" view to populate
   * its menu. So we have to register this button for the menu to work.
   *
   * Also, this menu duplicates its own entries from the "Web Developer"
   * menu in the system menu, under "Tools" main menu item. The system
   * menu is being hooked by "hookWebDeveloperMenu" which ends up calling
   * devtools/client/framework/browser-menu to create the items for real,
   * initDevTools, from onViewShowing is also calling browser-menu.
   */
  hookDeveloperToggle() {
    if (this.developerToggleCreated) {
      return;
    }

    let id = "developer-button";
    let widget = CustomizableUI.getWidget(id);
    if (widget && widget.provider == CustomizableUI.PROVIDER_API) {
      return;
    }
    let item = {
      id: id,
      type: "view",
      viewId: "PanelUI-developer",
      shortcutId: "key_toggleToolbox",
      tooltiptext: "developer-button.tooltiptext2",
      onViewShowing: (event) => {
        if (Services.prefs.getBoolPref(DEVTOOLS_ENABLED_PREF)) {
          // If DevTools are enabled, initialize DevTools to create all menuitems in the
          // system menu before trying to copy them.
          this.initDevTools("HamburgerMenu");
        }

        // Populate the subview with whatever menuitems are in the developer
        // menu. We skip menu elements, because the menu panel has no way
        // of dealing with those right now.
        let doc = event.target.ownerDocument;

        let menu = doc.getElementById("menuWebDeveloperPopup");

        let itemsToDisplay = [...menu.children];
        // Hardcode the addition of the "work offline" menuitem at the bottom:
        itemsToDisplay.push({localName: "menuseparator", getAttribute: () => {}});
        itemsToDisplay.push(doc.getElementById("goOfflineMenuitem"));

        let developerItems = doc.getElementById("PanelUI-developerItems");
        // Import private helpers from CustomizableWidgets
        let { clearSubview, fillSubviewFromMenuItems } =
          ChromeUtils.import("resource:///modules/CustomizableWidgets.jsm", {});
        clearSubview(developerItems);
        fillSubviewFromMenuItems(itemsToDisplay, developerItems);
      },
      onInit(anchor) {
        // Since onBeforeCreated already bails out when initialized, we can call
        // it right away.
        this.onBeforeCreated(anchor.ownerDocument);
      },
      onBeforeCreated: (doc) => {
        // The developer toggle needs the "key_toggleToolbox" <key> element.
        // In DEV EDITION, the toggle is added before 1st paint and hookKeyShortcuts() is
        // not called yet when CustomizableUI creates the widget.
        this.hookKeyShortcuts(doc.defaultView);

        // Bug 1223127, CUI should make this easier to do.
        if (doc.getElementById("PanelUI-developerItems")) {
          return;
        }
        let view = doc.createElement("panelview");
        view.id = "PanelUI-developerItems";
        let panel = doc.createElement("vbox");
        panel.setAttribute("class", "panel-subview-body");
        view.appendChild(panel);
        doc.getElementById("PanelUI-multiView").appendChild(view);
      }
    };
    CustomizableUI.createWidget(item);
    CustomizableWidgets.push(item);

    this.developerToggleCreated = true;
  },

  /*
   * We listen to the "Web Developer" system menu, which is under "Tools" main item.
   * This menu item is hardcoded empty in Firefox UI. We listen for its opening to
   * populate it lazily. Loading main DevTools module is going to populate it.
   */
  hookWebDeveloperMenu(window) {
    let menu = window.document.getElementById("webDeveloperMenu");
    let onPopupShowing = () => {
      if (!Services.prefs.getBoolPref(DEVTOOLS_ENABLED_PREF)) {
        return;
      }
      menu.removeEventListener("popupshowing", onPopupShowing);
      this.initDevTools("SystemMenu");
    };
    menu.addEventListener("popupshowing", onPopupShowing);
  },

  /**
   * Create a new menu item to enable DevTools and insert it DevTools's submenu in the
   * System Menu.
   */
  createDevToolsEnableMenuItem(window) {
    let {document} = window;

    // Create the menu item.
    let item = document.createElement("menuitem");
    item.id = "enableDeveloperTools";
    item.setAttribute("label", StartupBundle.GetStringFromName("enableDevTools.label"));
    item.setAttribute("accesskey",
      StartupBundle.GetStringFromName("enableDevTools.accesskey"));

    // The menu item should open the install page for DevTools.
    item.addEventListener("command", () => {
      this.openInstallPage("SystemMenu");
    });

    // Insert the menu item in the DevTools submenu.
    let systemMenuItem = document.getElementById("menuWebDeveloperPopup");
    systemMenuItem.appendChild(item);
  },

  /**
   * Update the visibility the menu item to enable DevTools.
   */
  updateDevToolsMenuItems(window) {
    let item = window.document.getElementById("enableDeveloperTools");
    item.hidden = Services.prefs.getBoolPref(DEVTOOLS_ENABLED_PREF);
  },

  /**
   * Loop on all windows and update the hidden attribute of the "enable DevTools" menu
   * item.
   */
  onEnabledPrefChanged() {
    let enumerator = Services.wm.getEnumerator("navigator:browser");
    while (enumerator.hasMoreElements()) {
      let window = enumerator.getNext();
      if (window.gBrowserInit && window.gBrowserInit.delayedStartupFinished) {
        this.updateDevToolsMenuItems(window);
      }
    }
  },

  /**
   * Check if the user is a DevTools user by looking at our selfxss pref.
   * This preference is incremented everytime the console is used (up to 5).
   *
   * @return {Boolean} true if the user can be considered as a devtools user.
   */
  isDevToolsUser() {
    let selfXssCount = Services.prefs.getIntPref("devtools.selfxss.count", 0);
    return selfXssCount > 0;
  },

  /**
   * Depending on some runtime parameters (command line arguments as well as existing
   * preferences), the DEVTOOLS_ENABLED_PREF might be forced to true.
   *
   * @param {Boolean} hasDevToolsFlag
   *        true if any DevTools command line argument was passed when starting Firefox.
   */
  setupEnabledPref(hasDevToolsFlag) {
    // Read the current experiment state.
    let experimentState = Services.prefs.getCharPref("devtools.onboarding.experiment");
    let isRegularExperiment = experimentState == "on";
    let isForcedExperiment = experimentState == "force";
    let isInExperiment = isRegularExperiment || isForcedExperiment;

    // Force devtools.enabled to true for users that are not part of the experiment.
    if (!isInExperiment) {
      Services.prefs.setBoolPref(DEVTOOLS_ENABLED_PREF, true);
      return;
    }

    // Force devtools.enabled to false once for each experiment user.
    if (!Services.prefs.getBoolPref("devtools.onboarding.experiment.flipped")) {
      Services.prefs.setBoolPref(DEVTOOLS_ENABLED_PREF, false);
      Services.prefs.setBoolPref("devtools.onboarding.experiment.flipped", true);
    }

    if (Services.prefs.getBoolPref(DEVTOOLS_ENABLED_PREF)) {
      // Nothing to do if DevTools are already enabled.
      return;
    }

    // We only consider checking the actual isDevToolsUser() if the user is in the
    // "regular" experiment group.
    let isDevToolsUser = isRegularExperiment && this.isDevToolsUser();

    let hasToolbarPref = Services.prefs.getBoolPref(TOOLBAR_VISIBLE_PREF, false);
    if (hasDevToolsFlag || hasToolbarPref || isDevToolsUser) {
      Services.prefs.setBoolPref(DEVTOOLS_ENABLED_PREF, true);
    }
  },

  hookKeyShortcuts(window) {
    let doc = window.document;

    // hookKeyShortcuts can be called both from hookWindow and from the developer toggle
    // onBeforeCreated. Make sure shortcuts are only added once per window.
    if (doc.getElementById("devtoolsKeyset")) {
      return;
    }

    let keyset = doc.createElement("keyset");
    keyset.setAttribute("id", "devtoolsKeyset");

    for (let key of KeyShortcuts) {
      let xulKey = this.createKey(doc, key, () => this.onKey(window, key));
      keyset.appendChild(xulKey);
    }

    // Appending a <key> element is not always enough. The <keyset> needs
    // to be detached and reattached to make sure the <key> is taken into
    // account (see bug 832984).
    let mainKeyset = doc.getElementById("mainKeyset");
    mainKeyset.parentNode.insertBefore(keyset, mainKeyset);
  },

  onKey(window, key) {
    if (!Services.prefs.getBoolPref(DEVTOOLS_ENABLED_PREF)) {
      let id = key.toolId || key.id;
      this.openInstallPage("KeyShortcut", id);
    } else {
      // Record the timing at which this event started in order to compute later in
      // gDevTools.showToolbox, the complete time it takes to open the toolbox.
      // i.e. especially take `initDevTools` into account.
      let startTime = window.performance.now();
      let require = this.initDevTools("KeyShortcut");
      let { gDevToolsBrowser } = require("devtools/client/framework/devtools-browser");
      gDevToolsBrowser.onKeyShortcut(window, key, startTime);
    }
  },

  // Create a <xul:key> DOM Element
  createKey(doc, { id, toolId, shortcut, modifiers: mod }, oncommand) {
    let k = doc.createElement("key");
    k.id = "key_" + (id || toolId);

    if (shortcut.startsWith("VK_")) {
      k.setAttribute("keycode", shortcut);
    } else {
      k.setAttribute("key", shortcut);
    }

    if (mod) {
      k.setAttribute("modifiers", mod);
    }

    // Bug 371900: command event is fired only if "oncommand" attribute is set.
    k.setAttribute("oncommand", ";");
    k.addEventListener("command", oncommand);

    return k;
  },

  initDevTools: function (reason) {
    // If an entry point is fired and tools are not enabled open the installation page
    if (!Services.prefs.getBoolPref(DEVTOOLS_ENABLED_PREF)) {
      this.openInstallPage(reason);
      return null;
    }

    if (reason && !this.recorded) {
      // Only save the first call for each firefox run as next call
      // won't necessarely start the tool. For example key shortcuts may
      // only change the currently selected tool.
      try {
        Services.telemetry.getHistogramById("DEVTOOLS_ENTRY_POINT")
                          .add(reason);
      } catch (e) {
        dump("DevTools telemetry entry point failed: " + e + "\n");
      }
      this.recorded = true;
    }

    this.initialized = true;
    let { require } = ChromeUtils.import("resource://devtools/shared/Loader.jsm", {});
    // Ensure loading main devtools module that hooks up into browser UI
    // and initialize all devtools machinery.
    require("devtools/client/framework/devtools-browser");
    return require;
  },

  /**
   * Open about:devtools to start the onboarding flow.
   *
   * @param {String} reason
   *        One of "KeyShortcut", "SystemMenu", "HamburgerMenu", "ContextMenu",
   *        "CommandLine".
   * @param {String} keyId
   *        Optional. If the onboarding flow was triggered by a keyboard shortcut, pass
   *        the shortcut key id (or toolId) to about:devtools.
   */
  openInstallPage: function (reason, keyId) {
    let { gBrowser } = Services.wm.getMostRecentWindow("navigator:browser");

    // Focus about:devtools tab if there is already one opened in the current window.
    for (let tab of gBrowser.tabs) {
      let browser = tab.linkedBrowser;
      // browser.documentURI might be undefined if the browser tab is still loading.
      let location = browser.documentURI ? browser.documentURI.spec : "";
      if (location.startsWith("about:devtools") &&
          !location.startsWith("about:devtools-toolbox")) {
        // Focus the existing about:devtools tab and bail out.
        gBrowser.selectedTab = tab;
        return;
      }
    }

    let url = "about:devtools";

    let params = [];
    if (reason) {
      params.push("reason=" + encodeURIComponent(reason));
    }

    let selectedBrowser = gBrowser.selectedBrowser;
    if (selectedBrowser) {
      params.push("tabid=" + selectedBrowser.outerWindowID);
    }

    if (keyId) {
      params.push("keyid=" + keyId);
    }

    if (params.length > 0) {
      url += "?" + params.join("&");
    }

    // Set relatedToCurrent: true to open the tab next to the current one.
    gBrowser.selectedTab = gBrowser.addTab(url, {relatedToCurrent: true});
  },

  handleConsoleFlag: function (cmdLine) {
    let window = Services.wm.getMostRecentWindow("devtools:webconsole");
    if (!window) {
      let require = this.initDevTools("CommandLine");
      let { HUDService } = require("devtools/client/webconsole/hudservice");
      let { console } = ChromeUtils.import("resource://gre/modules/Console.jsm", {});
      HUDService.toggleBrowserConsole().catch(console.error);
    } else {
      // the Browser Console was already open
      window.focus();
    }

    if (cmdLine.state == Ci.nsICommandLine.STATE_REMOTE_AUTO) {
      cmdLine.preventDefault = true;
    }
  },

  // Open the toolbox on the selected tab once the browser starts up.
  handleDevToolsFlag: function (window) {
    const require = this.initDevTools("CommandLine");
    const {gDevTools} = require("devtools/client/framework/devtools");
    const {TargetFactory} = require("devtools/client/framework/target");
    let target = TargetFactory.forTab(window.gBrowser.selectedTab);
    gDevTools.showToolbox(target);
  },

  _isRemoteDebuggingEnabled() {
    let remoteDebuggingEnabled = false;
    try {
      remoteDebuggingEnabled = kDebuggerPrefs.every(pref => {
        return Services.prefs.getBoolPref(pref);
      });
    } catch (ex) {
      let { console } = ChromeUtils.import("resource://gre/modules/Console.jsm", {});
      console.error(ex);
      return false;
    }
    if (!remoteDebuggingEnabled) {
      let errorMsg = "Could not run chrome debugger! You need the following " +
                     "prefs to be set to true: " + kDebuggerPrefs.join(", ");
      let { console } = ChromeUtils.import("resource://gre/modules/Console.jsm", {});
      console.error(new Error(errorMsg));
      // Dump as well, as we're doing this from a commandline, make sure people
      // don't miss it:
      dump(errorMsg + "\n");
    }
    return remoteDebuggingEnabled;
  },

  handleDebuggerFlag: function (cmdLine) {
    if (!this._isRemoteDebuggingEnabled()) {
      return;
    }

    let devtoolsThreadResumed = false;
    let pauseOnStartup = cmdLine.handleFlag("wait-for-jsdebugger", false);
    if (pauseOnStartup) {
      let observe = function (subject, topic, data) {
        devtoolsThreadResumed = true;
        Services.obs.removeObserver(observe, "devtools-thread-resumed");
      };
      Services.obs.addObserver(observe, "devtools-thread-resumed");
    }

    const { BrowserToolboxProcess } = ChromeUtils.import("resource://devtools/client/framework/ToolboxProcess.jsm", {});
    BrowserToolboxProcess.init();

    if (pauseOnStartup) {
      // Spin the event loop until the debugger connects.
      let tm = Cc["@mozilla.org/thread-manager;1"].getService();
      tm.spinEventLoopUntil(() => {
        return devtoolsThreadResumed;
      });
    }

    if (cmdLine.state == Ci.nsICommandLine.STATE_REMOTE_AUTO) {
      cmdLine.preventDefault = true;
    }
  },

  /**
   * Handle the --start-debugger-server command line flag. The options are:
   * --start-debugger-server
   *   The portOrPath parameter is boolean true in this case. Reads and uses the defaults
   *   from devtools.debugger.remote-port and devtools.debugger.remote-websocket prefs.
   *   The default values of these prefs are port 6000, WebSocket disabled.
   *
   * --start-debugger-server 6789
   *   Start the non-WebSocket server on port 6789.
   *
   * --start-debugger-server /path/to/filename
   *   Start the server on a Unix domain socket.
   *
   * --start-debugger-server ws:6789
   *   Start the WebSocket server on port 6789.
   *
   * --start-debugger-server ws:
   *   Start the WebSocket server on the default port (taken from d.d.remote-port)
   */
  handleDebuggerServerFlag: function (cmdLine, portOrPath) {
    if (!this._isRemoteDebuggingEnabled()) {
      return;
    }

    let webSocket = false;
    let defaultPort = Services.prefs.getIntPref("devtools.debugger.remote-port");
    if (portOrPath === true) {
      // Default to pref values if no values given on command line
      webSocket = Services.prefs.getBoolPref("devtools.debugger.remote-websocket");
      portOrPath = defaultPort;
    } else if (portOrPath.startsWith("ws:")) {
      webSocket = true;
      let port = portOrPath.slice(3);
      portOrPath = Number(port) ? port : defaultPort;
    }

    let { DevToolsLoader } =
      ChromeUtils.import("resource://devtools/shared/Loader.jsm", {});

    try {
      // Create a separate loader instance, so that we can be sure to receive
      // a separate instance of the DebuggingServer from the rest of the
      // devtools.  This allows us to safely use the tools against even the
      // actors and DebuggingServer itself, especially since we can mark
      // serverLoader as invisible to the debugger (unlike the usual loader
      // settings).
      let serverLoader = new DevToolsLoader();
      serverLoader.invisibleToDebugger = true;
      let { DebuggerServer: debuggerServer } =
        serverLoader.require("devtools/server/main");
      debuggerServer.init();
      debuggerServer.registerAllActors();
      debuggerServer.allowChromeProcess = true;

      let listener = debuggerServer.createListener();
      listener.portOrPath = portOrPath;
      listener.webSocket = webSocket;
      listener.open();
      dump("Started debugger server on " + portOrPath + "\n");
    } catch (e) {
      dump("Unable to start debugger server on " + portOrPath + ": " + e);
    }

    if (cmdLine.state == Ci.nsICommandLine.STATE_REMOTE_AUTO) {
      cmdLine.preventDefault = true;
    }
  },

  // Used by tests and the toolbox to register the same key shortcuts in toolboxes loaded
  // in a window window.
  get KeyShortcuts() {
    return KeyShortcuts;
  },
  get wrappedJSObject() {
    return this;
  },

  /* eslint-disable max-len */
  helpInfo: "  --jsconsole        Open the Browser Console.\n" +
            "  --jsdebugger       Open the Browser Toolbox.\n" +
            "  --wait-for-jsdebugger Spin event loop until JS debugger connects.\n" +
            "                     Enables debugging (some) application startup code paths.\n" +
            "                     Only has an effect when `--jsdebugger` is also supplied.\n" +
            "  --devtools         Open DevTools on initial load.\n" +
            "  --start-debugger-server [ws:][ <port> | <path> ] Start the debugger server on\n" +
            "                     a TCP port or Unix domain socket path. Defaults to TCP port\n" +
            "                     6000. Use WebSocket protocol if ws: prefix is specified.\n",
  /* eslint-disable max-len */

  classID: Components.ID("{9e9a9283-0ce9-4e4a-8f1c-ba129a032c32}"),
  QueryInterface: XPCOMUtils.generateQI([Ci.nsICommandLineHandler]),
};

/**
 * Singleton object that represents the JSON View in-content tool.
 * It has the same lifetime as the browser.
 */
const JsonView = {
  initialized: false,

  initialize: function () {
    // Prevent loading the frame script multiple times if we call this more than once.
    if (this.initialized) {
      return;
    }
    this.initialized = true;

    // Load JSON converter module. This converter is responsible
    // for handling 'application/json' documents and converting
    // them into a simple web-app that allows easy inspection
    // of the JSON data.
    Services.ppmm.loadProcessScript(
      "resource://devtools/client/jsonview/converter-observer.js",
      true);

    // Register for messages coming from the child process.
    // This is never removed as there is no particular need to unregister
    // it during shutdown.
    Services.ppmm.addMessageListener(
      "devtools:jsonview:save", this.onSave);
  },

  // Message handlers for events from child processes

  /**
   * Save JSON to a file needs to be implemented here
   * in the parent process.
   */
  onSave: function (message) {
    let chrome = Services.wm.getMostRecentWindow("navigator:browser");
    let browser = chrome.gBrowser.selectedBrowser;
    if (message.data === null) {
      // Save original contents
      chrome.saveBrowser(browser);
    } else {
      // The following code emulates saveBrowser, but:
      // - Uses the given blob URL containing the custom contents to save.
      // - Obtains the file name from the URL of the document, not the blob.
      let persistable = browser.frameLoader;
      persistable.startPersistence(0, {
        onDocumentReady(doc) {
          let uri = chrome.makeURI(doc.documentURI, doc.characterSet);
          let filename = chrome.getDefaultFileName(undefined, uri, doc, null);
          chrome.internalSave(message.data, doc, filename, null, doc.contentType,
            false, null, null, null, doc, false, null, undefined);
        },
        onError(status) {
          throw new Error("JSON Viewer's onSave failed in startPersistence");
        }
      });
    }
  }
};

this.NSGetFactory = XPCOMUtils.generateNSGetFactory(
  [DevToolsStartup]);