@lancercomet/utils/dist/images.js

My personal utils lib.

/**
 * 加载图片.
 *
 * @param {string} url
 * @returns {Promise<HTMLImageElement>}
 */
function loadImage(url) {
    return new Promise(function (resolve, reject) {
        var image = new Image();
        image.onload = function () {
            resolve(image);
        };
        image.onerror = function () {
            reject(new Error('Failed to load image ' + url));
        };
        image.src = url;
    });
}
/**
 * 使用 File 对象创建 HTMLImageElement.
 * File 必须为图片文件才能正常工作.
 *
 * @param {File} file 图片文件.
 * @returns {Promise<HTMLImageElement>} 图片节点.
 */
function createImageByFile(file) {
    var url = URL.createObjectURL(file);
    return loadImage(url);
}
/**
 * 通过图片创建 ImageData.
 *
 * @param {HTMLImageElement} image
 * @returns {ImageData}
 */
function createImageData(image) {
    var width = image.width, height = image.height;
    var canvas = document.createElement('canvas');
    canvas.width = width;
    canvas.height = height;
    var context = canvas.getContext('2d');
    context === null || context === void 0 ? void 0 : context.drawImage(image, 0, 0);
    return context === null || context === void 0 ? void 0 : context.getImageData(0, 0, width, height);
}
/**
 * 是否支持 WebP.
 *
 * @returns {boolean}
 */
function isSupportWebp() {
    // 某些 Android 浏览器不兹词 toDataURL.
    // SSR 环境下加入 try 进行容错.
    try {
        var canvas = document.createElement('canvas');
        if (canvas.getContext && canvas.getContext('2d')) {
            return canvas.toDataURL('image/webp').indexOf('data:image/webp') === 0;
        }
        else {
            return false;
        }
    }
    catch (error) {
        return false;
    }
}
export { createImageByFile, createImageData, isSupportWebp, loadImage };