149 lines
3.8 KiB
JavaScript
149 lines
3.8 KiB
JavaScript
; (function (win, lib) {
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var doc = win.document
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var docEl = doc.documentElement
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var metaEl = doc.querySelector('meta[name="viewport"]')
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var flexibleEl = doc.querySelector('meta[name="flexible"]')
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var dpr = 0
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var scale = 0
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var tid
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var flexible = lib.flexible || (lib.flexible = {})
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if (metaEl) {
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console.warn('将根据已有的meta标签来设置缩放比例')
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var match = metaEl.getAttribute('content').match(/initial\-scale=([\d\.]+)/)
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if (match) {
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scale = parseFloat(match[1])
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dpr = parseInt(1 / scale)
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}
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} else if (flexibleEl) {
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var content = flexibleEl.getAttribute('content')
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if (content) {
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var initialDpr = content.match(/initial\-dpr=([\d\.]+)/)
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var maximumDpr = content.match(/maximum\-dpr=([\d\.]+)/)
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if (initialDpr) {
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dpr = parseFloat(initialDpr[1])
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scale = parseFloat((1 / dpr).toFixed(2))
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}
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if (maximumDpr) {
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dpr = parseFloat(maximumDpr[1])
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scale = parseFloat((1 / dpr).toFixed(2))
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}
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}
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}
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if (!dpr && !scale) {
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var isAndroid = win.navigator.appVersion.match(/android/gi)
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var isIPhone = win.navigator.appVersion.match(/iphone/gi)
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var devicePixelRatio = win.devicePixelRatio
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if (isIPhone) {
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// iOS下，对于2和3的屏，用2倍的方案，其余的用1倍方案
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if (devicePixelRatio >= 3 && (!dpr || dpr >= 3)) {
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dpr = 3
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} else if (devicePixelRatio >= 2 && (!dpr || dpr >= 2)) {
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dpr = 2
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} else {
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dpr = 1
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}
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} else {
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// 其他设备下，仍旧使用1倍的方案
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dpr = 1
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}
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scale = 1 / dpr
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}
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docEl.setAttribute('data-dpr', dpr)
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if (!metaEl) {
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metaEl = doc.createElement('meta')
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metaEl.setAttribute('name', 'viewport')
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metaEl.setAttribute(
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'content',
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'initial-scale=' +
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scale +
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', maximum-scale=' +
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scale +
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', minimum-scale=' +
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scale +
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', user-scalable=no'
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)
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if (docEl.firstElementChild) {
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docEl.firstElementChild.appendChild(metaEl)
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} else {
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var wrap = doc.createElement('div')
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wrap.appendChild(metaEl)
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doc.write(wrap.innerHTML)
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}
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}
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function refreshRem() {
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var width = docEl.getBoundingClientRect().width
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if (width / dpr <= 1366) {
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width = 1366 * dpr
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} else if (width / dpr <= 1440) {
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width = 1440 * dpr
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} else if (width / dpr <= 1600) {
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width = 1600 * dpr
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} else if (width / dpr <= 1680) {
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width = 1680 * dpr
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} else if (width / dpr <= 1768) {
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width = 1768 * dpr
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} else if (width / dpr <= 1980) {
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width = 1980 * dpr
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} else if (width / dpr > 5760) {
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width = 5760 * dpr
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}
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var rem = width / 10
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docEl.style.fontSize = rem + 'px'
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flexible.rem = win.rem = rem
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}
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win.addEventListener(
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'resize',
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function () {
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clearTimeout(tid)
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tid = setTimeout(refreshRem, 300)
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},
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false
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)
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win.addEventListener(
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'pageshow',
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function (e) {
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if (e.persisted) {
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clearTimeout(tid)
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tid = setTimeout(refreshRem, 300)
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}
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},
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false
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)
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if (doc.readyState === 'complete') {
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doc.body.style.fontSize = 12 * dpr + 'px'
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} else {
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doc.addEventListener(
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'DOMContentLoaded',
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function (e) {
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doc.body.style.fontSize = 12 * dpr + 'px'
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},
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false
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)
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}
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refreshRem()
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flexible.dpr = win.dpr = dpr
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flexible.refreshRem = refreshRem
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flexible.rem2px = function (d) {
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var val = parseFloat(d) * this.rem
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if (typeof d === 'string' && d.match(/rem$/)) {
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val += 'px'
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}
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return val
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}
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flexible.px2rem = function (d) {
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var val = parseFloat(d) / this.rem
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if (typeof d === 'string' && d.match(/px$/)) {
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val += 'rem'
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}
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return val
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}
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})(window, window['lib'] || (window['lib'] = {}))
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