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authortoasted-nutbread <toasted-nutbread@users.noreply.github.com>2020-04-19 11:36:05 -0400
committerGitHub <noreply@github.com>2020-04-19 11:36:05 -0400
commita6344f635de2464465317b2ceeb6e19aef056848 (patch)
tree3c101c3dbf38dfb26bfb74bb0a38daedc8166811 /ext/bg/js/media-utility.js
parent3b2663ba0957c65be959ba18dc80e13625e28f02 (diff)
parent99c1a6a6bc0ce55eb2f20703a7f7f69c4bcefd9d (diff)
Merge pull request #446 from toasted-nutbread/dictionary-images
Dictionary images
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+/*
+ * Copyright (C) 2020 Yomichan Authors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ */
+
+/**
+ * mediaUtility is an object containing helper methods related to media processing.
+ */
+const mediaUtility = (() => {
+ /**
+ * Gets the file extension of a file path. URL search queries and hash
+ * fragments are not handled.
+ * @param path The path to the file.
+ * @returns The file extension, including the '.', or an empty string
+ * if there is no file extension.
+ */
+ function getFileNameExtension(path) {
+ const match = /\.[^./\\]*$/.exec(path);
+ return match !== null ? match[0] : '';
+ }
+
+ /**
+ * Gets an image file's media type using a file path.
+ * @param path The path to the file.
+ * @returns The media type string if it can be determined from the file path,
+ * otherwise null.
+ */
+ function getImageMediaTypeFromFileName(path) {
+ switch (getFileNameExtension(path).toLowerCase()) {
+ case '.apng':
+ return 'image/apng';
+ case '.bmp':
+ return 'image/bmp';
+ case '.gif':
+ return 'image/gif';
+ case '.ico':
+ case '.cur':
+ return 'image/x-icon';
+ case '.jpg':
+ case '.jpeg':
+ case '.jfif':
+ case '.pjpeg':
+ case '.pjp':
+ return 'image/jpeg';
+ case '.png':
+ return 'image/png';
+ case '.svg':
+ return 'image/svg+xml';
+ case '.tif':
+ case '.tiff':
+ return 'image/tiff';
+ case '.webp':
+ return 'image/webp';
+ default:
+ return null;
+ }
+ }
+
+ /**
+ * Attempts to load an image using a base64 encoded content and a media type.
+ * @param mediaType The media type for the image content.
+ * @param content The binary content for the image, encoded in base64.
+ * @returns A Promise which resolves with an HTMLImageElement instance on
+ * successful load, otherwise an error is thrown.
+ */
+ function loadImageBase64(mediaType, content) {
+ return new Promise((resolve, reject) => {
+ const image = new Image();
+ const eventListeners = new EventListenerCollection();
+ eventListeners.addEventListener(image, 'load', () => {
+ eventListeners.removeAllEventListeners();
+ resolve(image);
+ }, false);
+ eventListeners.addEventListener(image, 'error', () => {
+ eventListeners.removeAllEventListeners();
+ reject(new Error('Image failed to load'));
+ }, false);
+ image.src = `data:${mediaType};base64,${content}`;
+ });
+ }
+
+ return {
+ getImageMediaTypeFromFileName,
+ loadImageBase64
+ };
+})();