pdfjs-dist/lib/web/pdf_outline_viewer.js

/**
 * @licstart The following is the entire license notice for the
 * Javascript code in this page
 *
 * Copyright 2020 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");

const DEFAULT_TITLE = "\u2013";

class PDFOutlineViewer {
  constructor({
    container,
    linkService,
    eventBus
  }) {
    this.container = container;
    this.linkService = linkService;
    this.eventBus = eventBus;
    this.reset();

    eventBus._on("toggleoutlinetree", this.toggleOutlineTree.bind(this));
  }

  reset() {
    this.outline = null;
    this.lastToggleIsShow = true;
    this.container.textContent = "";
    this.container.classList.remove("outlineWithDeepNesting");
  }

  _dispatchEvent(outlineCount) {
    this.eventBus.dispatch("outlineloaded", {
      source: this,
      outlineCount
    });
  }

  _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 = () => {
      if (dest) {
        linkService.navigateTo(dest);
      }

      return false;
    };
  }

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

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

  _addToggleButton(div, {
    count,
    items
  }) {
    const toggler = document.createElement("div");
    toggler.className = "outlineItemToggler";

    if (count < 0 && Math.abs(count) === items.length) {
      toggler.classList.add("outlineItemsHidden");
    }

    toggler.onclick = evt => {
      evt.stopPropagation();
      toggler.classList.toggle("outlineItemsHidden");

      if (evt.shiftKey) {
        const shouldShowAll = !toggler.classList.contains("outlineItemsHidden");

        this._toggleOutlineItem(div, shouldShowAll);
      }
    };

    div.insertBefore(toggler, div.firstChild);
  }

  _toggleOutlineItem(root, show = false) {
    this.lastToggleIsShow = show;

    for (const toggler of root.querySelectorAll(".outlineItemToggler")) {
      toggler.classList.toggle("outlineItemsHidden", !show);
    }
  }

  toggleOutlineTree() {
    if (!this.outline) {
      return;
    }

    this._toggleOutlineItem(this.container, !this.lastToggleIsShow);
  }

  render({
    outline
  }) {
    let outlineCount = 0;

    if (this.outline) {
      this.reset();
    }

    this.outline = outline || null;

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

      return;
    }

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

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

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

        this._bindLink(element, item);

        this._setStyles(element, item);

        element.textContent = (0, _pdf.removeNullCharacters)(item.title) || DEFAULT_TITLE;
        div.appendChild(element);

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

          this._addToggleButton(div, item);

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

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

    if (hasAnyNesting) {
      this.container.classList.add("outlineWithDeepNesting");
      this.lastToggleIsShow = fragment.querySelectorAll(".outlineItemsHidden").length === 0;
    }

    this.container.appendChild(fragment);

    this._dispatchEvent(outlineCount);
  }

}

exports.PDFOutlineViewer = PDFOutlineViewer;