@alifd/next/lib/util/support.js

'use strict';

exports.__esModule = true;
exports.flex = exports.transition = exports.animation = undefined;

var _dom = require('./dom');

var _object = require('./object');

var animationEndEventNames = {
    WebkitAnimation: 'webkitAnimationEnd',
    OAnimation: 'oAnimationEnd',
    animation: 'animationend'
};

var transitionEventNames = {
    WebkitTransition: 'webkitTransitionEnd',
    OTransition: 'oTransitionEnd',
    transition: 'transitionend'
};

/**
 * 是否支持某些动效事件，如果支持，返回相应的end事件名
 * @private
 * @param  {Object<String>} names
 * @return {Object|false}
 */
function _supportEnd(names) {
    /* istanbul ignore if */
    if (!_dom.hasDOM) {
        return false;
    }

    var el = document.createElement('div');
    var ret = false;

    (0, _object.each)(names, function (val, key) {
        /* istanbul ignore else */
        if (el.style[key] !== undefined) {
            ret = { end: val };
            return false;
        }
    });

    return ret;
}

/**
 * 是否支持某些CSS属性
 * @private
 * @param  {Object<Array<String>>} names
 * @return {Boolean}       is support
 */
function _supportCSS(names) {
    /* istanbul ignore if */
    if (!_dom.hasDOM) {
        return false;
    }

    var el = document.createElement('div');
    var ret = false;

    (0, _object.each)(names, function (val, key) {
        (0, _object.each)(val, function (item) {
            try {
                el.style[key] = item;
                ret = ret || el.style[key] === item;
            } catch (e) {
                // It will be throw error when set unknown property under IE8
            }
            return !ret; // 如果有一个支持就返回false，后面不需要再判断
        });

        return !ret;
    });

    return ret;
}

/**
 * 是否支持animation以及动画结束事件名
 * @type {Object|false}
 * @property {String} end 动画结束事件名
 */
var animation = exports.animation = _supportEnd(animationEndEventNames);

/**
 * 是否支持transition以及过滤效果结束事件名
 * @type {Object|false}
 * @property {String} end 过渡效果结束事件名
 */
var transition = exports.transition = _supportEnd(transitionEventNames);

/**
 * 是否支持flex属性
 * @type {Boolean}
 */
var flex = exports.flex = _supportCSS({
    display: ['flex', '-webkit-flex', '-moz-flex', '-ms-flexbox']
});