pdf.js/web/firefoxcom.js

/* Copyright 2012 Mozilla Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import "../extensions/firefox/tools/l10n";
import { createObjectURL, PDFDataRangeTransport, shadow } from "pdfjs-lib";
import { DefaultExternalServices, PDFViewerApplication } from "./app.js";
import { BasePreferences } from "./preferences.js";
import { DEFAULT_SCALE_VALUE } from "./ui_utils.js";

if (
  typeof PDFJSDev === "undefined" ||
  !PDFJSDev.test("FIREFOX || MOZCENTRAL")
) {
  throw new Error(
    'Module "pdfjs-web/firefoxcom" shall not be used outside ' +
      "FIREFOX and MOZCENTRAL builds."
  );
}

const FirefoxCom = (function FirefoxComClosure() {
  return {
    /**
     * Creates an event that the extension is listening for and will
     * synchronously respond to.
     * NOTE: It is reccomended to use request() instead since one day we may not
     * be able to synchronously reply.
     * @param {string} action - The action to trigger.
     * @param {string} [data] - The data to send.
     * @returns {*} The response.
     */
    requestSync(action, data) {
      const request = document.createTextNode("");
      document.documentElement.appendChild(request);

      const sender = document.createEvent("CustomEvent");
      sender.initCustomEvent("pdf.js.message", true, false, {
        action,
        data,
        sync: true,
      });
      request.dispatchEvent(sender);
      const response = sender.detail.response;
      document.documentElement.removeChild(request);
      return response;
    },

    /**
     * Creates an event that the extension is listening for and will
     * asynchronously respond by calling the callback.
     * @param {string} action - The action to trigger.
     * @param {string} [data] - The data to send.
     * @param {Function} [callback] - Response callback that will be called
     *   with one data argument.
     */
    request(action, data, callback) {
      const request = document.createTextNode("");
      if (callback) {
        document.addEventListener("pdf.js.response", function listener(event) {
          const node = event.target;
          const response = event.detail.response;

          document.documentElement.removeChild(node);

          document.removeEventListener("pdf.js.response", listener);
          return callback(response);
        });
      }
      document.documentElement.appendChild(request);

      const sender = document.createEvent("CustomEvent");
      sender.initCustomEvent("pdf.js.message", true, false, {
        action,
        data,
        sync: false,
        responseExpected: !!callback,
      });
      return request.dispatchEvent(sender);
    },
  };
})();

class DownloadManager {
  constructor(options) {
    this.disableCreateObjectURL = false;
  }

  downloadUrl(url, filename) {
    FirefoxCom.request("download", {
      originalUrl: url,
      filename,
    });
  }

  downloadData(data, filename, contentType) {
    const blobUrl = createObjectURL(data, contentType);

    FirefoxCom.request("download", {
      blobUrl,
      originalUrl: blobUrl,
      filename,
      isAttachment: true,
    });
  }

  download(blob, url, filename) {
    const blobUrl = URL.createObjectURL(blob);
    const onResponse = err => {
      if (err && this.onerror) {
        this.onerror(err);
      }
      URL.revokeObjectURL(blobUrl);
    };

    FirefoxCom.request(
      "download",
      {
        blobUrl,
        originalUrl: url,
        filename,
      },
      onResponse
    );
  }
}

class FirefoxPreferences extends BasePreferences {
  async _writeToStorage(prefObj) {
    return new Promise(function(resolve) {
      FirefoxCom.request("setPreferences", prefObj, resolve);
    });
  }

  async _readFromStorage(prefObj) {
    return new Promise(function(resolve) {
      FirefoxCom.request("getPreferences", prefObj, function(prefStr) {
        const readPrefs = JSON.parse(prefStr);
        resolve(readPrefs);
      });
    });
  }
}

class MozL10n {
  constructor(mozL10n) {
    this.mozL10n = mozL10n;
  }

  async getLanguage() {
    return this.mozL10n.getLanguage();
  }

  async getDirection() {
    return this.mozL10n.getDirection();
  }

  async get(property, args, fallback) {
    return this.mozL10n.get(property, args, fallback);
  }

  async translate(element) {
    this.mozL10n.translate(element);
  }
}

(function listenFindEvents() {
  const events = [
    "find",
    "findagain",
    "findhighlightallchange",
    "findcasesensitivitychange",
    "findentirewordchange",
    "findbarclose",
  ];
  const handleEvent = function({ type, detail }) {
    if (!PDFViewerApplication.initialized) {
      return;
    }
    if (type === "findbarclose") {
      PDFViewerApplication.eventBus.dispatch(type, { source: window });
      return;
    }
    PDFViewerApplication.eventBus.dispatch("find", {
      source: window,
      type: type.substring("find".length),
      query: detail.query,
      phraseSearch: true,
      caseSensitive: !!detail.caseSensitive,
      entireWord: !!detail.entireWord,
      highlightAll: !!detail.highlightAll,
      findPrevious: !!detail.findPrevious,
    });
  };

  for (const event of events) {
    window.addEventListener(event, handleEvent);
  }
})();

(function listenZoomEvents() {
  const events = ["zoomin", "zoomout", "zoomreset"];
  const handleEvent = function({ type, detail }) {
    if (!PDFViewerApplication.initialized) {
      return;
    }
    // Avoid attempting to needlessly reset the zoom level *twice* in a row,
    // when using the `Ctrl + 0` keyboard shortcut.
    if (
      type === "zoomreset" &&
      PDFViewerApplication.pdfViewer.currentScaleValue === DEFAULT_SCALE_VALUE
    ) {
      return;
    }
    PDFViewerApplication.eventBus.dispatch(type, { source: window });
  };

  for (const event of events) {
    window.addEventListener(event, handleEvent);
  }
})();

class FirefoxComDataRangeTransport extends PDFDataRangeTransport {
  requestDataRange(begin, end) {
    FirefoxCom.request("requestDataRange", { begin, end });
  }

  abort() {
    // Sync call to ensure abort is really started.
    FirefoxCom.requestSync("abortLoading", null);
  }
}

class FirefoxExternalServices extends DefaultExternalServices {
  static updateFindControlState(data) {
    FirefoxCom.request("updateFindControlState", data);
  }

  static updateFindMatchesCount(data) {
    FirefoxCom.request("updateFindMatchesCount", data);
  }

  static initPassiveLoading(callbacks) {
    let pdfDataRangeTransport;

    window.addEventListener("message", function windowMessage(e) {
      if (e.source !== null) {
        // The message MUST originate from Chrome code.
        console.warn("Rejected untrusted message from " + e.origin);
        return;
      }
      const args = e.data;

      if (typeof args !== "object" || !("pdfjsLoadAction" in args)) {
        return;
      }
      switch (args.pdfjsLoadAction) {
        case "supportsRangedLoading":
          pdfDataRangeTransport = new FirefoxComDataRangeTransport(
            args.length,
            args.data,
            args.done
          );

          callbacks.onOpenWithTransport(
            args.pdfUrl,
            args.length,
            pdfDataRangeTransport
          );
          break;
        case "range":
          pdfDataRangeTransport.onDataRange(args.begin, args.chunk);
          break;
        case "rangeProgress":
          pdfDataRangeTransport.onDataProgress(args.loaded);
          break;
        case "progressiveRead":
          pdfDataRangeTransport.onDataProgressiveRead(args.chunk);

          // Don't forget to report loading progress as well, since otherwise
          // the loadingBar won't update when `disableRange=true` is set.
          pdfDataRangeTransport.onDataProgress(args.loaded, args.total);
          break;
        case "progressiveDone":
          if (pdfDataRangeTransport) {
            pdfDataRangeTransport.onDataProgressiveDone();
          }
          break;
        case "progress":
          callbacks.onProgress(args.loaded, args.total);
          break;
        case "complete":
          if (!args.data) {
            callbacks.onError(args.errorCode);
            break;
          }
          callbacks.onOpenWithData(args.data);
          break;
      }
    });
    FirefoxCom.requestSync("initPassiveLoading", null);
  }

  static fallback(data, callback) {
    FirefoxCom.request("fallback", data, callback);
  }

  static reportTelemetry(data) {
    FirefoxCom.request("reportTelemetry", JSON.stringify(data));
  }

  static createDownloadManager(options) {
    return new DownloadManager(options);
  }

  static createPreferences() {
    return new FirefoxPreferences();
  }

  static createL10n(options) {
    const mozL10n = document.mozL10n;
    // TODO refactor mozL10n.setExternalLocalizerServices
    return new MozL10n(mozL10n);
  }

  static get supportsIntegratedFind() {
    const support = FirefoxCom.requestSync("supportsIntegratedFind");
    return shadow(this, "supportsIntegratedFind", support);
  }

  static get supportsDocumentFonts() {
    const support = FirefoxCom.requestSync("supportsDocumentFonts");
    return shadow(this, "supportsDocumentFonts", support);
  }

  static get supportedMouseWheelZoomModifierKeys() {
    const support = FirefoxCom.requestSync(
      "supportedMouseWheelZoomModifierKeys"
    );
    return shadow(this, "supportedMouseWheelZoomModifierKeys", support);
  }
}
PDFViewerApplication.externalServices = FirefoxExternalServices;

// l10n.js for Firefox extension expects services to be set.
document.mozL10n.setExternalLocalizerServices({
  getLocale() {
    return FirefoxCom.requestSync("getLocale", null);
  },

  getStrings(key) {
    return FirefoxCom.requestSync("getStrings", key);
  },
});

export { DownloadManager, FirefoxCom };