pdfjs-dist/lib/web/pdf_link_service.js

/**
 * @licstart The following is the entire license notice for the
 * Javascript code in this page
 *
 * Copyright 2021 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 = void 0;

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

class PDFLinkService {
  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;
    this._pagesRefCache = null;
  }

  setDocument(pdfDocument, baseUrl = null) {
    this.baseUrl = baseUrl;
    this.pdfDocument = pdfDocument;
    this._pagesRefCache = Object.create(null);
  }

  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 === null) {
        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
    });
  }

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

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

      if ("zoom" in params) {
        const zoomArgs = params.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 ("pagemode" in params) {
        this.eventBus.dispatch("pagemode", {
          source: this,
          mode: params.pagemode
        });
      }

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

      try {
        dest = JSON.parse(dest);

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

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

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

  executeNamedAction(action) {
    switch (action) {
      case "GoBack":
        if (this.pdfHistory) {
          this.pdfHistory.back();
        }

        break;

      case "GoForward":
        if (this.pdfHistory) {
          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[refStr] = pageNum;
  }

  _cachedPageNumber(pageRef) {
    const refStr = pageRef.gen === 0 ? `${pageRef.num}R` : `${pageRef.num}R${pageRef.gen}`;
    return this._pagesRefCache?.[refStr] || null;
  }

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

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

}

exports.PDFLinkService = PDFLinkService;

function 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;
}

class SimpleLinkService {
  constructor() {
    this.externalLinkTarget = null;
    this.externalLinkRel = null;
    this.externalLinkEnabled = true;
    this._ignoreDestinationZoom = false;
  }

  get pagesCount() {
    return 0;
  }

  get page() {
    return 0;
  }

  set page(value) {}

  get rotation() {
    return 0;
  }

  set rotation(value) {}

  async goToDestination(dest) {}

  goToPage(val) {}

  getDestinationHash(dest) {
    return "#";
  }

  getAnchorUrl(hash) {
    return "#";
  }

  setHash(hash) {}

  executeNamedAction(action) {}

  cachePageRef(pageNum, pageRef) {}

  isPageVisible(pageNumber) {
    return true;
  }

  isPageCached(pageNumber) {
    return true;
  }

}

exports.SimpleLinkService = SimpleLinkService;