SingleFile/lib/single-file/processors/hooks/content/content-hooks-frames.js

/*
 * Copyright 2010-2020 Gildas Lormeau
 * contact : gildas.lormeau <at> gmail.com
 * 
 * This file is part of SingleFile.
 *
 *   The code in this file is free software: you can redistribute it and/or 
 *   modify it under the terms of the GNU Affero General Public License 
 *   (GNU AGPL) as published by the Free Software Foundation, either version 3
 *   of the License, or (at your option) any later version.
 * 
 *   The code in this file is distributed in the hope that it will be useful, 
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of 
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero 
 *   General Public License for more details.
 *
 *   As additional permission under GNU AGPL version 3 section 7, you may 
 *   distribute UNMODIFIED VERSIONS OF THIS file without the copy of the GNU 
 *   AGPL normally required by section 4, provided you include this license 
 *   notice and a URL through which recipients can access the Corresponding 
 *   Source.
 */

/* global window */

this.singlefile.lib.processors.hooks.content.frames = this.singlefile.lib.processors.hooks.content.frames || (() => {

	const LOAD_DEFERRED_IMAGES_START_EVENT = "single-file-load-deferred-images-start";
	const LOAD_DEFERRED_IMAGES_END_EVENT = "single-file-load-deferred-images-end";
	const LOAD_DEFERRED_IMAGES_KEEP_ZOOM_LEVEL_START_EVENT = "single-file-load-deferred-images-keep-zoom-level-start";
	const LOAD_DEFERRED_IMAGES_KEEP_ZOOM_LEVEL_END_EVENT = "single-file-load-deferred-images-keep-zoom-level-end";
	const LOAD_DEFERRED_IMAGES_RESET_ZOOM_LEVEL_END_EVENT = "single-file-load-deferred-images-keep-zoom-level-reset";
	const BLOCK_COOKIES_START_EVENT = "single-file-block-cookies-start";
	const BLOCK_COOKIES_END_EVENT = "single-file-block-cookies-end";
	const BLOCK_STORAGE_START_EVENT = "single-file-block-storage-start";
	const BLOCK_STORAGE_END_EVENT = "single-file-block-storage-end";
	const LOAD_IMAGE_EVENT = "single-file-load-image";
	const IMAGE_LOADED_EVENT = "single-file-image-loaded";
	const NEW_FONT_FACE_EVENT = "single-file-new-font-face";

	const browser = this.browser;
	const addEventListener = (type, listener, options) => window.addEventListener(type, listener, options);
	const dispatchEvent = event => window.dispatchEvent(event);
	const CustomEvent = window.CustomEvent;
	const document = window.document;
	const HTMLDocument = window.HTMLDocument;
	const FileReader = window.FileReader;
	const Blob = window.Blob;

	const fontFaces = [];

	if (document instanceof HTMLDocument) {
		if (browser && browser.runtime && browser.runtime.getURL) {
			addEventListener(NEW_FONT_FACE_EVENT, event => {
				const detail = event.detail;
				if (!fontFaces.find(fontFace => JSON.stringify(fontFace) == JSON.stringify(detail))) {
					fontFaces.push(event.detail);
				}
			});
			let scriptElement = document.createElement("script");
			scriptElement.textContent = "(" + injectedScript.toString() + ")()";
			(document.documentElement || document).appendChild(scriptElement);
			scriptElement.remove();
			scriptElement = document.createElement("script");
			scriptElement.src = browser.runtime.getURL("/lib/single-file/processors/hooks/content/content-hooks-frames-web.js");
			scriptElement.async = false;
			(document.documentElement || document).appendChild(scriptElement);
			scriptElement.remove();
		}
	}

	return {
		getFontsData: () => fontFaces,
		loadDeferredImagesStart: options => {
			if (options.loadDeferredImagesBlockCookies) {
				dispatchEvent(new CustomEvent(BLOCK_COOKIES_START_EVENT));
			}
			if (options.loadDeferredImagesBlockStorage) {
				dispatchEvent(new CustomEvent(BLOCK_STORAGE_START_EVENT));
			}
			if (options.loadDeferredImagesKeepZoomLevel) {
				dispatchEvent(new CustomEvent(LOAD_DEFERRED_IMAGES_KEEP_ZOOM_LEVEL_START_EVENT));
			} else {
				dispatchEvent(new CustomEvent(LOAD_DEFERRED_IMAGES_START_EVENT));
			}
		},
		loadDeferredImagesEnd: options => {
			if (options.loadDeferredImagesBlockCookies) {
				dispatchEvent(new CustomEvent(BLOCK_COOKIES_END_EVENT));
			}
			if (options.loadDeferredImagesBlockStorage) {
				dispatchEvent(new CustomEvent(BLOCK_STORAGE_END_EVENT));
			}
			if (options.loadDeferredImagesKeepZoomLevel) {
				dispatchEvent(new CustomEvent(LOAD_DEFERRED_IMAGES_KEEP_ZOOM_LEVEL_END_EVENT));
			} else {
				dispatchEvent(new CustomEvent(LOAD_DEFERRED_IMAGES_END_EVENT));
			}
		},
		loadDeferredImagesResetZoomLevel: () => {
			dispatchEvent(new CustomEvent(LOAD_DEFERRED_IMAGES_RESET_ZOOM_LEVEL_END_EVENT));
		},
		LOAD_IMAGE_EVENT,
		IMAGE_LOADED_EVENT
	};

	function injectedScript() {
		const console = window.console;
		const warn = (console && console.warn && ((...args) => console.warn(...args))) || (() => { });
		const NEW_FONT_FACE_EVENT = "single-file-new-font-face";
		const FONT_STYLE_PROPERTIES = {
			family: "font-family",
			style: "font-style",
			weight: "font-weight",
			stretch: "font-stretch",
			unicodeRange: "unicode-range",
			variant: "font-variant",
			featureSettings: "font-feature-settings"
		};

		if (window.FontFace) {
			const FontFace = window.FontFace;
			let warningFontFaceDisplayed;
			window.FontFace = function () {
				if (!warningFontFaceDisplayed) {
					warn("SingleFile is hooking the FontFace constructor to get font URLs."); // eslint-disable-line no-console
					warningFontFaceDisplayed = true;
				}
				const detail = {};
				detail["font-family"] = arguments[0];
				detail.src = arguments[1];
				const descriptors = arguments[2];
				if (descriptors) {
					Object.keys(descriptors).forEach(descriptor => {
						if (FONT_STYLE_PROPERTIES[descriptor]) {
							detail[FONT_STYLE_PROPERTIES[descriptor]] = descriptors[descriptor];
						}
					});
				}
				if (detail.src instanceof ArrayBuffer) {
					const reader = new FileReader();
					reader.readAsDataURL(new Blob([detail.src]));
					reader.addEventListener("load", () => {
						detail.src = "url(" + reader.result + ")";
						dispatchEvent(new CustomEvent(NEW_FONT_FACE_EVENT, { detail }));
					});
				} else {
					dispatchEvent(new CustomEvent(NEW_FONT_FACE_EVENT, { detail }));
				}
				return new FontFace(...arguments);
			};
			window.FontFace.toString = function () { return "function FontFace() { [native code] }"; };
		}
	}

})();