pdfjs-dist/lib/web/pdf_outline_viewer.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.PDFOutlineViewer = void 0;

var _pdf = require("../pdf");

var _base_tree_viewer = require("./base_tree_viewer.js");

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

class PDFOutlineViewer extends _base_tree_viewer.BaseTreeViewer {
  constructor(options) {
    super(options);
    this.linkService = options.linkService;

    this.eventBus._on("toggleoutlinetree", this._toggleAllTreeItems.bind(this));

    this.eventBus._on("currentoutlineitem", this._currentOutlineItem.bind(this));

    this.eventBus._on("pagechanging", evt => {
      this._currentPageNumber = evt.pageNumber;
    });

    this.eventBus._on("pagesloaded", evt => {
      this._isPagesLoaded = !!evt.pagesCount;

      if (this._currentOutlineItemCapability && !this._currentOutlineItemCapability.settled) {
        this._currentOutlineItemCapability.resolve(this._isPagesLoaded);
      }
    });

    this.eventBus._on("sidebarviewchanged", evt => {
      this._sidebarView = evt.view;
    });
  }

  reset() {
    super.reset();
    this._outline = null;
    this._pageNumberToDestHashCapability = null;
    this._currentPageNumber = 1;
    this._isPagesLoaded = false;

    if (this._currentOutlineItemCapability && !this._currentOutlineItemCapability.settled) {
      this._currentOutlineItemCapability.resolve(false);
    }

    this._currentOutlineItemCapability = null;
  }

  _dispatchEvent(outlineCount) {
    this._currentOutlineItemCapability = (0, _pdf.createPromiseCapability)();

    if (outlineCount === 0 || this._pdfDocument?.loadingParams.disableAutoFetch) {
      this._currentOutlineItemCapability.resolve(false);
    } else if (this._isPagesLoaded) {
      this._currentOutlineItemCapability.resolve(true);
    }

    this.eventBus.dispatch("outlineloaded", {
      source: this,
      outlineCount,
      currentOutlineItemPromise: this._currentOutlineItemCapability.promise
    });
  }

  _bindLink(element, {
    url,
    newWindow,
    dest
  }) {
    const {
      linkService
    } = this;

    if (url) {
      (0, _pdf.addLinkAttributes)(element, {
        url,
        target: newWindow ? _pdf.LinkTarget.BLANK : linkService.externalLinkTarget,
        rel: linkService.externalLinkRel,
        enabled: linkService.externalLinkEnabled
      });
      return;
    }

    element.href = linkService.getDestinationHash(dest);

    element.onclick = evt => {
      this._updateCurrentTreeItem(evt.target.parentNode);

      if (dest) {
        linkService.goToDestination(dest);
      }

      return false;
    };
  }

  _setStyles(element, {
    bold,
    italic
  }) {
    if (bold) {
      element.style.fontWeight = "bold";
    }

    if (italic) {
      element.style.fontStyle = "italic";
    }
  }

  _addToggleButton(div, {
    count,
    items
  }) {
    let hidden = false;

    if (count < 0) {
      let totalCount = items.length;

      if (totalCount > 0) {
        const queue = [...items];

        while (queue.length > 0) {
          const {
            count: nestedCount,
            items: nestedItems
          } = queue.shift();

          if (nestedCount > 0 && nestedItems.length > 0) {
            totalCount += nestedItems.length;
            queue.push(...nestedItems);
          }
        }
      }

      if (Math.abs(count) === totalCount) {
        hidden = true;
      }
    }

    super._addToggleButton(div, hidden);
  }

  _toggleAllTreeItems() {
    if (!this._outline) {
      return;
    }

    super._toggleAllTreeItems();
  }

  render({
    outline,
    pdfDocument
  }) {
    if (this._outline) {
      this.reset();
    }

    this._outline = outline || null;
    this._pdfDocument = pdfDocument || null;

    if (!outline) {
      this._dispatchEvent(0);

      return;
    }

    const fragment = document.createDocumentFragment();
    const queue = [{
      parent: fragment,
      items: outline
    }];
    let outlineCount = 0,
        hasAnyNesting = false;

    while (queue.length > 0) {
      const levelData = queue.shift();

      for (const item of levelData.items) {
        const div = document.createElement("div");
        div.className = "treeItem";
        const element = document.createElement("a");

        this._bindLink(element, item);

        this._setStyles(element, item);

        element.textContent = this._normalizeTextContent(item.title);
        div.appendChild(element);

        if (item.items.length > 0) {
          hasAnyNesting = true;

          this._addToggleButton(div, item);

          const itemsDiv = document.createElement("div");
          itemsDiv.className = "treeItems";
          div.appendChild(itemsDiv);
          queue.push({
            parent: itemsDiv,
            items: item.items
          });
        }

        levelData.parent.appendChild(div);
        outlineCount++;
      }
    }

    this._finishRendering(fragment, outlineCount, hasAnyNesting);
  }

  async _currentOutlineItem() {
    if (!this._isPagesLoaded) {
      throw new Error("_currentOutlineItem: All pages have not been loaded.");
    }

    if (!this._outline || !this._pdfDocument) {
      return;
    }

    const pageNumberToDestHash = await this._getPageNumberToDestHash(this._pdfDocument);

    if (!pageNumberToDestHash) {
      return;
    }

    this._updateCurrentTreeItem(null);

    if (this._sidebarView !== _ui_utils.SidebarView.OUTLINE) {
      return;
    }

    for (let i = this._currentPageNumber; i > 0; i--) {
      const destHash = pageNumberToDestHash.get(i);

      if (!destHash) {
        continue;
      }

      const linkElement = this.container.querySelector(`a[href="${destHash}"]`);

      if (!linkElement) {
        continue;
      }

      this._scrollToCurrentTreeItem(linkElement.parentNode);

      break;
    }
  }

  async _getPageNumberToDestHash(pdfDocument) {
    if (this._pageNumberToDestHashCapability) {
      return this._pageNumberToDestHashCapability.promise;
    }

    this._pageNumberToDestHashCapability = (0, _pdf.createPromiseCapability)();
    const pageNumberToDestHash = new Map(),
          pageNumberNesting = new Map();
    const queue = [{
      nesting: 0,
      items: this._outline
    }];

    while (queue.length > 0) {
      const levelData = queue.shift(),
            currentNesting = levelData.nesting;

      for (const {
        dest,
        items
      } of levelData.items) {
        let explicitDest, pageNumber;

        if (typeof dest === "string") {
          explicitDest = await pdfDocument.getDestination(dest);

          if (pdfDocument !== this._pdfDocument) {
            return null;
          }
        } else {
          explicitDest = dest;
        }

        if (Array.isArray(explicitDest)) {
          const [destRef] = explicitDest;

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

            if (!pageNumber) {
              try {
                pageNumber = (await pdfDocument.getPageIndex(destRef)) + 1;

                if (pdfDocument !== this._pdfDocument) {
                  return null;
                }

                this.linkService.cachePageRef(pageNumber, destRef);
              } catch (ex) {}
            }
          } else if (Number.isInteger(destRef)) {
            pageNumber = destRef + 1;
          }

          if (Number.isInteger(pageNumber) && (!pageNumberToDestHash.has(pageNumber) || currentNesting > pageNumberNesting.get(pageNumber))) {
            const destHash = this.linkService.getDestinationHash(dest);
            pageNumberToDestHash.set(pageNumber, destHash);
            pageNumberNesting.set(pageNumber, currentNesting);
          }
        }

        if (items.length > 0) {
          queue.push({
            nesting: currentNesting + 1,
            items
          });
        }
      }
    }

    this._pageNumberToDestHashCapability.resolve(pageNumberToDestHash.size > 0 ? pageNumberToDestHash : null);

    return this._pageNumberToDestHashCapability.promise;
  }

}

exports.PDFOutlineViewer = PDFOutlineViewer;