pdfjs-dist/lib/display/display_utils.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.addLinkAttributes = addLinkAttributes;
exports.getFilenameFromUrl = getFilenameFromUrl;
exports.isFetchSupported = isFetchSupported;
exports.isValidFetchUrl = isValidFetchUrl;
exports.loadScript = loadScript;
exports.deprecated = deprecated;
exports.releaseImageResources = releaseImageResources;
exports.PDFDateString = exports.StatTimer = exports.DOMSVGFactory = exports.DOMCMapReaderFactory = exports.DOMCanvasFactory = exports.DEFAULT_LINK_REL = exports.LinkTarget = exports.RenderingCancelledException = exports.PageViewport = void 0;

var _util = require("../shared/util.js");

const DEFAULT_LINK_REL = "noopener noreferrer nofollow";
exports.DEFAULT_LINK_REL = DEFAULT_LINK_REL;
const SVG_NS = "http://www.w3.org/2000/svg";

class DOMCanvasFactory {
  create(width, height) {
    if (width <= 0 || height <= 0) {
      throw new Error("Invalid canvas size");
    }

    const canvas = document.createElement("canvas");
    const context = canvas.getContext("2d");
    canvas.width = width;
    canvas.height = height;
    return {
      canvas,
      context
    };
  }

  reset(canvasAndContext, width, height) {
    if (!canvasAndContext.canvas) {
      throw new Error("Canvas is not specified");
    }

    if (width <= 0 || height <= 0) {
      throw new Error("Invalid canvas size");
    }

    canvasAndContext.canvas.width = width;
    canvasAndContext.canvas.height = height;
  }

  destroy(canvasAndContext) {
    if (!canvasAndContext.canvas) {
      throw new Error("Canvas is not specified");
    }

    canvasAndContext.canvas.width = 0;
    canvasAndContext.canvas.height = 0;
    canvasAndContext.canvas = null;
    canvasAndContext.context = null;
  }

}

exports.DOMCanvasFactory = DOMCanvasFactory;

class DOMCMapReaderFactory {
  constructor({
    baseUrl = null,
    isCompressed = false
  }) {
    this.baseUrl = baseUrl;
    this.isCompressed = isCompressed;
  }

  async fetch({
    name
  }) {
    if (!this.baseUrl) {
      throw new Error('The CMap "baseUrl" parameter must be specified, ensure that ' + 'the "cMapUrl" and "cMapPacked" API parameters are provided.');
    }

    if (!name) {
      throw new Error("CMap name must be specified.");
    }

    const url = this.baseUrl + name + (this.isCompressed ? ".bcmap" : "");
    const compressionType = this.isCompressed ? _util.CMapCompressionType.BINARY : _util.CMapCompressionType.NONE;

    if (isFetchSupported() && isValidFetchUrl(url, document.baseURI)) {
      return fetch(url).then(async response => {
        if (!response.ok) {
          throw new Error(response.statusText);
        }

        let cMapData;

        if (this.isCompressed) {
          cMapData = new Uint8Array((await response.arrayBuffer()));
        } else {
          cMapData = (0, _util.stringToBytes)((await response.text()));
        }

        return {
          cMapData,
          compressionType
        };
      }).catch(reason => {
        throw new Error(`Unable to load ${this.isCompressed ? "binary " : ""}` + `CMap at: ${url}`);
      });
    }

    return new Promise((resolve, reject) => {
      const request = new XMLHttpRequest();
      request.open("GET", url, true);

      if (this.isCompressed) {
        request.responseType = "arraybuffer";
      }

      request.onreadystatechange = () => {
        if (request.readyState !== XMLHttpRequest.DONE) {
          return;
        }

        if (request.status === 200 || request.status === 0) {
          let cMapData;

          if (this.isCompressed && request.response) {
            cMapData = new Uint8Array(request.response);
          } else if (!this.isCompressed && request.responseText) {
            cMapData = (0, _util.stringToBytes)(request.responseText);
          }

          if (cMapData) {
            resolve({
              cMapData,
              compressionType
            });
            return;
          }
        }

        reject(new Error(request.statusText));
      };

      request.send(null);
    }).catch(reason => {
      throw new Error(`Unable to load ${this.isCompressed ? "binary " : ""}` + `CMap at: ${url}`);
    });
  }

}

exports.DOMCMapReaderFactory = DOMCMapReaderFactory;

class DOMSVGFactory {
  create(width, height) {
    (0, _util.assert)(width > 0 && height > 0, "Invalid SVG dimensions");
    const svg = document.createElementNS(SVG_NS, "svg:svg");
    svg.setAttribute("version", "1.1");
    svg.setAttribute("width", width + "px");
    svg.setAttribute("height", height + "px");
    svg.setAttribute("preserveAspectRatio", "none");
    svg.setAttribute("viewBox", "0 0 " + width + " " + height);
    return svg;
  }

  createElement(type) {
    (0, _util.assert)(typeof type === "string", "Invalid SVG element type");
    return document.createElementNS(SVG_NS, type);
  }

}

exports.DOMSVGFactory = DOMSVGFactory;

class PageViewport {
  constructor({
    viewBox,
    scale,
    rotation,
    offsetX = 0,
    offsetY = 0,
    dontFlip = false
  }) {
    this.viewBox = viewBox;
    this.scale = scale;
    this.rotation = rotation;
    this.offsetX = offsetX;
    this.offsetY = offsetY;
    const centerX = (viewBox[2] + viewBox[0]) / 2;
    const centerY = (viewBox[3] + viewBox[1]) / 2;
    let rotateA, rotateB, rotateC, rotateD;
    rotation = rotation % 360;
    rotation = rotation < 0 ? rotation + 360 : rotation;

    switch (rotation) {
      case 180:
        rotateA = -1;
        rotateB = 0;
        rotateC = 0;
        rotateD = 1;
        break;

      case 90:
        rotateA = 0;
        rotateB = 1;
        rotateC = 1;
        rotateD = 0;
        break;

      case 270:
        rotateA = 0;
        rotateB = -1;
        rotateC = -1;
        rotateD = 0;
        break;

      default:
        rotateA = 1;
        rotateB = 0;
        rotateC = 0;
        rotateD = -1;
        break;
    }

    if (dontFlip) {
      rotateC = -rotateC;
      rotateD = -rotateD;
    }

    let offsetCanvasX, offsetCanvasY;
    let width, height;

    if (rotateA === 0) {
      offsetCanvasX = Math.abs(centerY - viewBox[1]) * scale + offsetX;
      offsetCanvasY = Math.abs(centerX - viewBox[0]) * scale + offsetY;
      width = Math.abs(viewBox[3] - viewBox[1]) * scale;
      height = Math.abs(viewBox[2] - viewBox[0]) * scale;
    } else {
      offsetCanvasX = Math.abs(centerX - viewBox[0]) * scale + offsetX;
      offsetCanvasY = Math.abs(centerY - viewBox[1]) * scale + offsetY;
      width = Math.abs(viewBox[2] - viewBox[0]) * scale;
      height = Math.abs(viewBox[3] - viewBox[1]) * scale;
    }

    this.transform = [rotateA * scale, rotateB * scale, rotateC * scale, rotateD * scale, offsetCanvasX - rotateA * scale * centerX - rotateC * scale * centerY, offsetCanvasY - rotateB * scale * centerX - rotateD * scale * centerY];
    this.width = width;
    this.height = height;
  }

  clone({
    scale = this.scale,
    rotation = this.rotation,
    offsetX = this.offsetX,
    offsetY = this.offsetY,
    dontFlip = false
  } = {}) {
    return new PageViewport({
      viewBox: this.viewBox.slice(),
      scale,
      rotation,
      offsetX,
      offsetY,
      dontFlip
    });
  }

  convertToViewportPoint(x, y) {
    return _util.Util.applyTransform([x, y], this.transform);
  }

  convertToViewportRectangle(rect) {
    const topLeft = _util.Util.applyTransform([rect[0], rect[1]], this.transform);

    const bottomRight = _util.Util.applyTransform([rect[2], rect[3]], this.transform);

    return [topLeft[0], topLeft[1], bottomRight[0], bottomRight[1]];
  }

  convertToPdfPoint(x, y) {
    return _util.Util.applyInverseTransform([x, y], this.transform);
  }

}

exports.PageViewport = PageViewport;

class RenderingCancelledException extends _util.BaseException {
  constructor(msg, type) {
    super(msg);
    this.type = type;
  }

}

exports.RenderingCancelledException = RenderingCancelledException;
const LinkTarget = {
  NONE: 0,
  SELF: 1,
  BLANK: 2,
  PARENT: 3,
  TOP: 4
};
exports.LinkTarget = LinkTarget;

function addLinkAttributes(link, {
  url,
  target,
  rel,
  enabled = true
} = {}) {
  (0, _util.assert)(url && typeof url === "string", 'addLinkAttributes: A valid "url" parameter must provided.');
  const urlNullRemoved = (0, _util.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;
}

function getFilenameFromUrl(url) {
  const anchor = url.indexOf("#");
  const query = url.indexOf("?");
  const end = Math.min(anchor > 0 ? anchor : url.length, query > 0 ? query : url.length);
  return url.substring(url.lastIndexOf("/", end) + 1, end);
}

class StatTimer {
  constructor() {
    this.started = Object.create(null);
    this.times = [];
  }

  time(name) {
    if (name in this.started) {
      (0, _util.warn)(`Timer is already running for ${name}`);
    }

    this.started[name] = Date.now();
  }

  timeEnd(name) {
    if (!(name in this.started)) {
      (0, _util.warn)(`Timer has not been started for ${name}`);
    }

    this.times.push({
      name,
      start: this.started[name],
      end: Date.now()
    });
    delete this.started[name];
  }

  toString() {
    const outBuf = [];
    let longest = 0;

    for (const time of this.times) {
      const name = time.name;

      if (name.length > longest) {
        longest = name.length;
      }
    }

    for (const time of this.times) {
      const duration = time.end - time.start;
      outBuf.push(`${time.name.padEnd(longest)} ${duration}ms\n`);
    }

    return outBuf.join("");
  }

}

exports.StatTimer = StatTimer;

function isFetchSupported() {
  return typeof fetch !== "undefined" && typeof Response !== "undefined" && "body" in Response.prototype && typeof ReadableStream !== "undefined";
}

function isValidFetchUrl(url, baseUrl) {
  try {
    const {
      protocol
    } = baseUrl ? new URL(url, baseUrl) : new URL(url);
    return protocol === "http:" || protocol === "https:";
  } catch (ex) {
    return false;
  }
}

function loadScript(src) {
  return new Promise((resolve, reject) => {
    const script = document.createElement("script");
    script.src = src;
    script.onload = resolve;

    script.onerror = function () {
      reject(new Error(`Cannot load script at: ${script.src}`));
    };

    (document.head || document.documentElement).appendChild(script);
  });
}

function deprecated(details) {
  console.log("Deprecated API usage: " + details);
}

function releaseImageResources(img) {
  (0, _util.assert)(img instanceof Image, "Invalid `img` parameter.");
  const url = img.src;

  if (typeof url === "string" && url.startsWith("blob:") && URL.revokeObjectURL) {
    URL.revokeObjectURL(url);
  }

  img.removeAttribute("src");
}

let pdfDateStringRegex;

class PDFDateString {
  static toDateObject(input) {
    if (!input || !(0, _util.isString)(input)) {
      return null;
    }

    if (!pdfDateStringRegex) {
      pdfDateStringRegex = new RegExp("^D:" + "(\\d{4})" + "(\\d{2})?" + "(\\d{2})?" + "(\\d{2})?" + "(\\d{2})?" + "(\\d{2})?" + "([Z|+|-])?" + "(\\d{2})?" + "'?" + "(\\d{2})?" + "'?");
    }

    const matches = pdfDateStringRegex.exec(input);

    if (!matches) {
      return null;
    }

    const year = parseInt(matches[1], 10);
    let month = parseInt(matches[2], 10);
    month = month >= 1 && month <= 12 ? month - 1 : 0;
    let day = parseInt(matches[3], 10);
    day = day >= 1 && day <= 31 ? day : 1;
    let hour = parseInt(matches[4], 10);
    hour = hour >= 0 && hour <= 23 ? hour : 0;
    let minute = parseInt(matches[5], 10);
    minute = minute >= 0 && minute <= 59 ? minute : 0;
    let second = parseInt(matches[6], 10);
    second = second >= 0 && second <= 59 ? second : 0;
    const universalTimeRelation = matches[7] || "Z";
    let offsetHour = parseInt(matches[8], 10);
    offsetHour = offsetHour >= 0 && offsetHour <= 23 ? offsetHour : 0;
    let offsetMinute = parseInt(matches[9], 10) || 0;
    offsetMinute = offsetMinute >= 0 && offsetMinute <= 59 ? offsetMinute : 0;

    if (universalTimeRelation === "-") {
      hour += offsetHour;
      minute += offsetMinute;
    } else if (universalTimeRelation === "+") {
      hour -= offsetHour;
      minute -= offsetMinute;
    }

    return new Date(Date.UTC(year, month, day, hour, minute, second));
  }

}

exports.PDFDateString = PDFDateString;