gecko-dev/toolkit/actors/UAWidgetsDateTimeBoxChild.jsm

/* vim: set ts=2 sw=2 sts=2 et tw=80: */
/* 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/. */
"use strict";

var EXPORTED_SYMBOLS = ["UAWidgetsDateTimeBoxChild"];

const { Services } = ChromeUtils.import("resource://gre/modules/Services.jsm");

const HANDLED_ELEMENTS = ["input"];

class UAWidgetsDateTimeBoxChild extends JSWindowActorChild {
  constructor() {
    super();

    this.widgets = new WeakMap();
    this.prefsCache = new Map();
  }

  handleEvent(aEvent) {
    if (HANDLED_ELEMENTS.includes(aEvent.target.localName)) {
      switch (aEvent.type) {
        case "UAWidgetSetupOrChange":
          this.setupOrNotifyWidget(aEvent.target);
          break;
        case "UAWidgetTeardown":
          this.teardownWidget(aEvent.target);
          break;
      }

      // In case we are a nested frame, prevent the message manager of the
      // parent frame from receving the event.
      aEvent.stopPropagation();
    }
  }

  setupOrNotifyWidget(aElement) {
    let widget = this.widgets.get(aElement);
    if (!widget) {
      this.setupWidget(aElement);
      return;
    }
    if (typeof widget.onchange == "function") {
      try {
        widget.onchange();
      } catch (ex) {
        Cu.reportError(ex);
      }
    }
  }

  setupWidget(aElement) {
    let uri;
    let widgetName;
    let prefKeys = [];
    switch (aElement.localName) {
      case "input":
        uri = "chrome://global/content/elements/datetimebox.js";
        widgetName = "DateTimeBoxWidget";
        break;
    }

    if (!uri || !widgetName) {
      Cu.reportError(
        "Getting a UAWidgetSetupOrChange event on undefined element."
      );
      return;
    }

    let shadowRoot = aElement.openOrClosedShadowRoot;
    if (!shadowRoot) {
      Cu.reportError(
        "Getting a UAWidgetSetupOrChange event without the Shadow Root."
      );
      return;
    }

    let isSystemPrincipal = aElement.nodePrincipal.isSystemPrincipal;
    let sandbox = isSystemPrincipal
      ? Object.create(null)
      : Cu.getUAWidgetScope(aElement.nodePrincipal);

    if (!sandbox[widgetName]) {
      Services.scriptloader.loadSubScript(uri, sandbox);
    }

    let prefs = Cu.cloneInto(
      this.getPrefsForUAWidget(widgetName, prefKeys),
      sandbox
    );

    let widget = new sandbox[widgetName](shadowRoot, prefs);
    if (!isSystemPrincipal) {
      widget = widget.wrappedJSObject;
    }
    this.widgets.set(aElement, widget);
    try {
      widget.onsetup();
    } catch (ex) {
      Cu.reportError(ex);
    }
  }

  teardownWidget(aElement) {
    let widget = this.widgets.get(aElement);
    if (!widget) {
      return;
    }
    if (typeof widget.destructor == "function") {
      try {
        widget.destructor();
      } catch (ex) {
        Cu.reportError(ex);
      }
    }
    this.widgets.delete(aElement);
  }

  getPrefsForUAWidget(aWidgetName, aPrefKeys) {
    let result = this.prefsCache.get(aWidgetName);
    if (result) {
      return result;
    }

    result = {};
    for (let key of aPrefKeys) {
      switch (Services.prefs.getPrefType(key)) {
        case Ci.nsIPrefBranch.PREF_BOOL: {
          result[key] = Services.prefs.getBoolPref(key);
          break;
        }
        case Ci.nsIPrefBranch.PREF_INT: {
          result[key] = Services.prefs.getIntPref(key);
          break;
        }
        case Ci.nsIPrefBranch.PREF_STRING: {
          result[key] = Services.prefs.getStringPref(key);
          break;
        }
      }
    }

    this.prefsCache.set(aWidgetName, result);
    return result;
  }
}