pdfjs-dist/lib/web/pdf_link_service.js

/**
 * @licstart The following is the entire license notice for the
 * JavaScript code in this page
 *
 * Copyright 2022 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.
 *
 * @licend The above is the entire license notice for the
 * JavaScript code in this page
 */
"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.SimpleLinkService = exports.PDFLinkService = exports.LinkTarget = void 0;

var _ui_utils = require("./ui_utils.js");

const DEFAULT_LINK_REL = "noopener noreferrer nofollow";
const LinkTarget = {
  NONE: 0,
  SELF: 1,
  BLANK: 2,
  PARENT: 3,
  TOP: 4
};
exports.LinkTarget = LinkTarget;

function addLinkAttributes(link, {
  url,
  target,
  rel,
  enabled = true
} = {}) {
  if (!url || typeof url !== "string") {
    throw new Error('A valid "url" parameter must provided.');
  }

  const urlNullRemoved = (0, _ui_utils.removeNullCharacters)(url);

  if (enabled) {
    link.href = link.title = urlNullRemoved;
  } else {
    link.href = "";
    link.title = `Disabled: ${urlNullRemoved}`;

    link.onclick = () => {
      return false;
    };
  }

  let targetStr = "";

  switch (target) {
    case LinkTarget.NONE:
      break;

    case LinkTarget.SELF:
      targetStr = "_self";
      break;

    case LinkTarget.BLANK:
      targetStr = "_blank";
      break;

    case LinkTarget.PARENT:
      targetStr = "_parent";
      break;

    case LinkTarget.TOP:
      targetStr = "_top";
      break;
  }

  link.target = targetStr;
  link.rel = typeof rel === "string" ? rel : DEFAULT_LINK_REL;
}

class PDFLinkService {
  #pagesRefCache = new Map();

  constructor({
    eventBus,
    externalLinkTarget = null,
    externalLinkRel = null,
    ignoreDestinationZoom = false
  } = {}) {
    this.eventBus = eventBus;
    this.externalLinkTarget = externalLinkTarget;
    this.externalLinkRel = externalLinkRel;
    this.externalLinkEnabled = true;
    this._ignoreDestinationZoom = ignoreDestinationZoom;
    this.baseUrl = null;
    this.pdfDocument = null;
    this.pdfViewer = null;
    this.pdfHistory = null;
  }

  setDocument(pdfDocument, baseUrl = null) {
    this.baseUrl = baseUrl;
    this.pdfDocument = pdfDocument;
    this.#pagesRefCache.clear();
  }

  setViewer(pdfViewer) {
    this.pdfViewer = pdfViewer;
  }

  setHistory(pdfHistory) {
    this.pdfHistory = pdfHistory;
  }

  get pagesCount() {
    return this.pdfDocument ? this.pdfDocument.numPages : 0;
  }

  get page() {
    return this.pdfViewer.currentPageNumber;
  }

  set page(value) {
    this.pdfViewer.currentPageNumber = value;
  }

  get rotation() {
    return this.pdfViewer.pagesRotation;
  }

  set rotation(value) {
    this.pdfViewer.pagesRotation = value;
  }

  #goToDestinationHelper(rawDest, namedDest = null, explicitDest) {
    const destRef = explicitDest[0];
    let pageNumber;

    if (typeof destRef === "object" && destRef !== null) {
      pageNumber = this._cachedPageNumber(destRef);

      if (!pageNumber) {
        this.pdfDocument.getPageIndex(destRef).then(pageIndex => {
          this.cachePageRef(pageIndex + 1, destRef);
          this.#goToDestinationHelper(rawDest, namedDest, explicitDest);
        }).catch(() => {
          console.error(`PDFLinkService.#goToDestinationHelper: "${destRef}" is not ` + `a valid page reference, for dest="${rawDest}".`);
        });
        return;
      }
    } else if (Number.isInteger(destRef)) {
      pageNumber = destRef + 1;
    } else {
      console.error(`PDFLinkService.#goToDestinationHelper: "${destRef}" is not ` + `a valid destination reference, for dest="${rawDest}".`);
      return;
    }

    if (!pageNumber || pageNumber < 1 || pageNumber > this.pagesCount) {
      console.error(`PDFLinkService.#goToDestinationHelper: "${pageNumber}" is not ` + `a valid page number, for dest="${rawDest}".`);
      return;
    }

    if (this.pdfHistory) {
      this.pdfHistory.pushCurrentPosition();
      this.pdfHistory.push({
        namedDest,
        explicitDest,
        pageNumber
      });
    }

    this.pdfViewer.scrollPageIntoView({
      pageNumber,
      destArray: explicitDest,
      ignoreDestinationZoom: this._ignoreDestinationZoom
    });
  }

  async goToDestination(dest) {
    if (!this.pdfDocument) {
      return;
    }

    let namedDest, explicitDest;

    if (typeof dest === "string") {
      namedDest = dest;
      explicitDest = await this.pdfDocument.getDestination(dest);
    } else {
      namedDest = null;
      explicitDest = await dest;
    }

    if (!Array.isArray(explicitDest)) {
      console.error(`PDFLinkService.goToDestination: "${explicitDest}" is not ` + `a valid destination array, for dest="${dest}".`);
      return;
    }

    this.#goToDestinationHelper(dest, namedDest, explicitDest);
  }

  goToPage(val) {
    if (!this.pdfDocument) {
      return;
    }

    const pageNumber = typeof val === "string" && this.pdfViewer.pageLabelToPageNumber(val) || val | 0;

    if (!(Number.isInteger(pageNumber) && pageNumber > 0 && pageNumber <= this.pagesCount)) {
      console.error(`PDFLinkService.goToPage: "${val}" is not a valid page.`);
      return;
    }

    if (this.pdfHistory) {
      this.pdfHistory.pushCurrentPosition();
      this.pdfHistory.pushPage(pageNumber);
    }

    this.pdfViewer.scrollPageIntoView({
      pageNumber
    });
  }

  addLinkAttributes(link, url, newWindow = false) {
    addLinkAttributes(link, {
      url,
      target: newWindow ? LinkTarget.BLANK : this.externalLinkTarget,
      rel: this.externalLinkRel,
      enabled: this.externalLinkEnabled
    });
  }

  getDestinationHash(dest) {
    if (typeof dest === "string") {
      if (dest.length > 0) {
        return this.getAnchorUrl("#" + escape(dest));
      }
    } else if (Array.isArray(dest)) {
      const str = JSON.stringify(dest);

      if (str.length > 0) {
        return this.getAnchorUrl("#" + escape(str));
      }
    }

    return this.getAnchorUrl("");
  }

  getAnchorUrl(anchor) {
    return (this.baseUrl || "") + anchor;
  }

  setHash(hash) {
    if (!this.pdfDocument) {
      return;
    }

    let pageNumber, dest;

    if (hash.includes("=")) {
      const params = (0, _ui_utils.parseQueryString)(hash);

      if (params.has("search")) {
        this.eventBus.dispatch("findfromurlhash", {
          source: this,
          query: params.get("search").replace(/"/g, ""),
          phraseSearch: params.get("phrase") === "true"
        });
      }

      if (params.has("page")) {
        pageNumber = params.get("page") | 0 || 1;
      }

      if (params.has("zoom")) {
        const zoomArgs = params.get("zoom").split(",");
        const zoomArg = zoomArgs[0];
        const zoomArgNumber = parseFloat(zoomArg);

        if (!zoomArg.includes("Fit")) {
          dest = [null, {
            name: "XYZ"
          }, zoomArgs.length > 1 ? zoomArgs[1] | 0 : null, zoomArgs.length > 2 ? zoomArgs[2] | 0 : null, zoomArgNumber ? zoomArgNumber / 100 : zoomArg];
        } else {
          if (zoomArg === "Fit" || zoomArg === "FitB") {
            dest = [null, {
              name: zoomArg
            }];
          } else if (zoomArg === "FitH" || zoomArg === "FitBH" || zoomArg === "FitV" || zoomArg === "FitBV") {
            dest = [null, {
              name: zoomArg
            }, zoomArgs.length > 1 ? zoomArgs[1] | 0 : null];
          } else if (zoomArg === "FitR") {
            if (zoomArgs.length !== 5) {
              console.error('PDFLinkService.setHash: Not enough parameters for "FitR".');
            } else {
              dest = [null, {
                name: zoomArg
              }, zoomArgs[1] | 0, zoomArgs[2] | 0, zoomArgs[3] | 0, zoomArgs[4] | 0];
            }
          } else {
            console.error(`PDFLinkService.setHash: "${zoomArg}" is not a valid zoom value.`);
          }
        }
      }

      if (dest) {
        this.pdfViewer.scrollPageIntoView({
          pageNumber: pageNumber || this.page,
          destArray: dest,
          allowNegativeOffset: true
        });
      } else if (pageNumber) {
        this.page = pageNumber;
      }

      if (params.has("pagemode")) {
        this.eventBus.dispatch("pagemode", {
          source: this,
          mode: params.get("pagemode")
        });
      }

      if (params.has("nameddest")) {
        this.goToDestination(params.get("nameddest"));
      }
    } else {
      dest = unescape(hash);

      try {
        dest = JSON.parse(dest);

        if (!Array.isArray(dest)) {
          dest = dest.toString();
        }
      } catch (ex) {}

      if (typeof dest === "string" || PDFLinkService.#isValidExplicitDestination(dest)) {
        this.goToDestination(dest);
        return;
      }

      console.error(`PDFLinkService.setHash: "${unescape(hash)}" is not a valid destination.`);
    }
  }

  executeNamedAction(action) {
    switch (action) {
      case "GoBack":
        this.pdfHistory?.back();
        break;

      case "GoForward":
        this.pdfHistory?.forward();
        break;

      case "NextPage":
        this.pdfViewer.nextPage();
        break;

      case "PrevPage":
        this.pdfViewer.previousPage();
        break;

      case "LastPage":
        this.page = this.pagesCount;
        break;

      case "FirstPage":
        this.page = 1;
        break;

      default:
        break;
    }

    this.eventBus.dispatch("namedaction", {
      source: this,
      action
    });
  }

  cachePageRef(pageNum, pageRef) {
    if (!pageRef) {
      return;
    }

    const refStr = pageRef.gen === 0 ? `${pageRef.num}R` : `${pageRef.num}R${pageRef.gen}`;
    this.#pagesRefCache.set(refStr, pageNum);
  }

  _cachedPageNumber(pageRef) {
    if (!pageRef) {
      return null;
    }

    const refStr = pageRef.gen === 0 ? `${pageRef.num}R` : `${pageRef.num}R${pageRef.gen}`;
    return this.#pagesRefCache.get(refStr) || null;
  }

  isPageVisible(pageNumber) {
    return this.pdfViewer.isPageVisible(pageNumber);
  }

  isPageCached(pageNumber) {
    return this.pdfViewer.isPageCached(pageNumber);
  }

  static #isValidExplicitDestination(dest) {
    if (!Array.isArray(dest)) {
      return false;
    }

    const destLength = dest.length;

    if (destLength < 2) {
      return false;
    }

    const page = dest[0];

    if (!(typeof page === "object" && Number.isInteger(page.num) && Number.isInteger(page.gen)) && !(Number.isInteger(page) && page >= 0)) {
      return false;
    }

    const zoom = dest[1];

    if (!(typeof zoom === "object" && typeof zoom.name === "string")) {
      return false;
    }

    let allowNull = true;

    switch (zoom.name) {
      case "XYZ":
        if (destLength !== 5) {
          return false;
        }

        break;

      case "Fit":
      case "FitB":
        return destLength === 2;

      case "FitH":
      case "FitBH":
      case "FitV":
      case "FitBV":
        if (destLength !== 3) {
          return false;
        }

        break;

      case "FitR":
        if (destLength !== 6) {
          return false;
        }

        allowNull = false;
        break;

      default:
        return false;
    }

    for (let i = 2; i < destLength; i++) {
      const param = dest[i];

      if (!(typeof param === "number" || allowNull && param === null)) {
        return false;
      }
    }

    return true;
  }

}

exports.PDFLinkService = PDFLinkService;

class SimpleLinkService {
  constructor() {
    this.externalLinkEnabled = true;
  }

  get pagesCount() {
    return 0;
  }

  get page() {
    return 0;
  }

  set page(value) {}

  get rotation() {
    return 0;
  }

  set rotation(value) {}

  async goToDestination(dest) {}

  goToPage(val) {}

  addLinkAttributes(link, url, newWindow = false) {
    addLinkAttributes(link, {
      url,
      enabled: this.externalLinkEnabled
    });
  }

  getDestinationHash(dest) {
    return "#";
  }

  getAnchorUrl(hash) {
    return "#";
  }

  setHash(hash) {}

  executeNamedAction(action) {}

  cachePageRef(pageNum, pageRef) {}

  isPageVisible(pageNumber) {
    return true;
  }

  isPageCached(pageNumber) {
    return true;
  }

}

exports.SimpleLinkService = SimpleLinkService;