pdfjs-dist/lib/test/unit/custom_spec.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";

var _api = require("../../display/api.js");

var _test_utils = require("./test_utils.js");

function getTopLeftPixel(canvasContext) {
  const imgData = canvasContext.getImageData(0, 0, 1, 1);
  return {
    r: imgData.data[0],
    g: imgData.data[1],
    b: imgData.data[2],
    a: imgData.data[3]
  };
}

describe("custom canvas rendering", function () {
  const transparentGetDocumentParams = (0, _test_utils.buildGetDocumentParams)("transparent.pdf");
  let CanvasFactory;
  let loadingTask;
  let page;
  beforeAll(async function () {
    CanvasFactory = new _api.DefaultCanvasFactory();
    loadingTask = (0, _api.getDocument)(transparentGetDocumentParams);
    const doc = await loadingTask.promise;
    const data = await doc.getPage(1);
    page = data;
  });
  afterAll(async function () {
    CanvasFactory = null;
    page = null;
    await loadingTask.destroy();
  });
  it("renders to canvas with a default white background", async function () {
    const viewport = page.getViewport({
      scale: 1
    });
    const canvasAndCtx = CanvasFactory.create(viewport.width, viewport.height);
    const renderTask = page.render({
      canvasContext: canvasAndCtx.context,
      viewport
    });
    await renderTask.promise;
    expect(getTopLeftPixel(canvasAndCtx.context)).toEqual({
      r: 255,
      g: 255,
      b: 255,
      a: 255
    });
    CanvasFactory.destroy(canvasAndCtx);
  });
  it("renders to canvas with a custom background", async function () {
    const viewport = page.getViewport({
      scale: 1
    });
    const canvasAndCtx = CanvasFactory.create(viewport.width, viewport.height);
    const renderTask = page.render({
      canvasContext: canvasAndCtx.context,
      viewport,
      background: "rgba(255,0,0,1.0)"
    });
    await renderTask.promise;
    expect(getTopLeftPixel(canvasAndCtx.context)).toEqual({
      r: 255,
      g: 0,
      b: 0,
      a: 255
    });
    CanvasFactory.destroy(canvasAndCtx);
  });
});
describe("custom ownerDocument", function () {
  const FontFace = globalThis.FontFace;

  const checkFont = font => /g_d\d+_f1/.test(font.family);

  const checkFontFaceRule = rule => /^@font-face {font-family:"g_d\d+_f1";src:/.test(rule);

  beforeEach(() => {
    globalThis.FontFace = function MockFontFace(name) {
      this.family = name;
    };
  });
  afterEach(() => {
    globalThis.FontFace = FontFace;
  });

  function getMocks() {
    const elements = [];

    const createElement = name => {
      let element = typeof document !== "undefined" && document.createElement(name);

      if (name === "style") {
        element = {
          tagName: name,
          sheet: {
            cssRules: [],

            insertRule(rule) {
              this.cssRules.push(rule);
            }

          }
        };
        Object.assign(element, {
          remove() {
            this.remove.called = true;
          }

        });
      }

      elements.push(element);
      return element;
    };

    const ownerDocument = {
      fonts: new Set(),
      createElement,
      documentElement: {
        getElementsByTagName: () => [{
          appendChild: () => {}
        }]
      }
    };
    const CanvasFactory = new _api.DefaultCanvasFactory({
      ownerDocument
    });
    return {
      elements,
      ownerDocument,
      CanvasFactory
    };
  }

  it("should use given document for loading fonts (with Font Loading API)", async function () {
    const {
      ownerDocument,
      elements,
      CanvasFactory
    } = getMocks();
    const getDocumentParams = (0, _test_utils.buildGetDocumentParams)("TrueType_without_cmap.pdf", {
      disableFontFace: false,
      ownerDocument
    });
    const loadingTask = (0, _api.getDocument)(getDocumentParams);
    const doc = await loadingTask.promise;
    const page = await doc.getPage(1);
    const viewport = page.getViewport({
      scale: 1
    });
    const canvasAndCtx = CanvasFactory.create(viewport.width, viewport.height);
    await page.render({
      canvasContext: canvasAndCtx.context,
      viewport
    }).promise;
    const style = elements.find(element => element.tagName === "style");
    expect(style).toBeFalsy();
    expect(ownerDocument.fonts.size).toBeGreaterThanOrEqual(1);
    expect(Array.from(ownerDocument.fonts).find(checkFont)).toBeTruthy();
    await doc.destroy();
    await loadingTask.destroy();
    CanvasFactory.destroy(canvasAndCtx);
    expect(ownerDocument.fonts.size).toBe(0);
  });
  it("should use given document for loading fonts (with CSS rules)", async function () {
    const {
      ownerDocument,
      elements,
      CanvasFactory
    } = getMocks();
    ownerDocument.fonts = null;
    const getDocumentParams = (0, _test_utils.buildGetDocumentParams)("TrueType_without_cmap.pdf", {
      disableFontFace: false,
      ownerDocument
    });
    const loadingTask = (0, _api.getDocument)(getDocumentParams);
    const doc = await loadingTask.promise;
    const page = await doc.getPage(1);
    const viewport = page.getViewport({
      scale: 1
    });
    const canvasAndCtx = CanvasFactory.create(viewport.width, viewport.height);
    await page.render({
      canvasContext: canvasAndCtx.context,
      viewport
    }).promise;
    const style = elements.find(element => element.tagName === "style");
    expect(style.sheet.cssRules.length).toBeGreaterThanOrEqual(1);
    expect(style.sheet.cssRules.find(checkFontFaceRule)).toBeTruthy();
    await doc.destroy();
    await loadingTask.destroy();
    CanvasFactory.destroy(canvasAndCtx);
    expect(style.remove.called).toBe(true);
  });
});