New file |
| | |
| | | //flexible.js |
| | | (function(win, lib) { |
| | | var doc = win.document; |
| | | var docEl = doc.documentElement; |
| | | var metaEl = doc.querySelector('meta[name="viewport"]'); |
| | | var flexibleEl = doc.querySelector('meta[name="flexible"]'); |
| | | var dpr = 0; |
| | | var scale = 0; |
| | | var tid; |
| | | var flexible = lib.flexible || (lib.flexible = {}); |
| | | |
| | | if (metaEl) { |
| | | console.warn('将根据已有的meta标签来设置缩放比例'); |
| | | var match = metaEl.getAttribute('content').match(/initial\-scale=([\d\.]+)/); |
| | | if (match) { |
| | | scale = parseFloat(match[1]); |
| | | dpr = parseInt(1 / scale); |
| | | } |
| | | } else if (flexibleEl) { |
| | | var content = flexibleEl.getAttribute('content'); |
| | | if (content) { |
| | | var initialDpr = content.match(/initial\-dpr=([\d\.]+)/); |
| | | var maximumDpr = content.match(/maximum\-dpr=([\d\.]+)/); |
| | | if (initialDpr) { |
| | | dpr = parseFloat(initialDpr[1]); |
| | | scale = parseFloat((1 / dpr).toFixed(2)); |
| | | } |
| | | if (maximumDpr) { |
| | | dpr = parseFloat(maximumDpr[1]); |
| | | scale = parseFloat((1 / dpr).toFixed(2)); |
| | | } |
| | | } |
| | | } |
| | | |
| | | if (!dpr && !scale) { |
| | | var isAndroid = win.navigator.appVersion.match(/android/gi); |
| | | var isIPhone = win.navigator.appVersion.match(/iphone/gi); |
| | | var devicePixelRatio = win.devicePixelRatio; |
| | | if (isIPhone) { |
| | | // iOS下,对于2和3的屏,用2倍的方案,其余的用1倍方案 |
| | | if (devicePixelRatio >= 3 && (!dpr || dpr >= 3)) { |
| | | dpr = 3; |
| | | } else if (devicePixelRatio >= 2 && (!dpr || dpr >= 2)){ |
| | | dpr = 2; |
| | | } else { |
| | | dpr = 1; |
| | | } |
| | | } else { |
| | | // 其他设备下,仍旧使用1倍的方案 |
| | | dpr = 1; |
| | | } |
| | | scale = 1 / dpr; |
| | | } |
| | | |
| | | docEl.setAttribute('data-dpr', dpr); |
| | | if (!metaEl) { |
| | | metaEl = doc.createElement('meta'); |
| | | metaEl.setAttribute('name', 'viewport'); |
| | | metaEl.setAttribute('content', 'initial-scale=' + scale + ', maximum-scale=' + scale + ', minimum-scale=' + scale + ', user-scalable=no'); |
| | | if (docEl.firstElementChild) { |
| | | docEl.firstElementChild.appendChild(metaEl); |
| | | } else { |
| | | var wrap = doc.createElement('div'); |
| | | wrap.appendChild(metaEl); |
| | | doc.write(wrap.innerHTML); |
| | | } |
| | | } |
| | | |
| | | function refreshRem(){ |
| | | var width = docEl.getBoundingClientRect().width; |
| | | if (width / dpr > 540) { |
| | | width = width * dpr; |
| | | } |
| | | var rem = width / 10; |
| | | docEl.style.fontSize = rem + 'px'; |
| | | flexible.rem = win.rem = rem; |
| | | } |
| | | |
| | | win.addEventListener('resize', function() { |
| | | clearTimeout(tid); |
| | | tid = setTimeout(refreshRem, 300); |
| | | }, false); |
| | | win.addEventListener('pageshow', function(e) { |
| | | if (e.persisted) { |
| | | clearTimeout(tid); |
| | | tid = setTimeout(refreshRem, 300); |
| | | } |
| | | }, false); |
| | | |
| | | if (doc.readyState === 'complete') { |
| | | doc.body.style.fontSize = 12 * dpr + 'px'; |
| | | } else { |
| | | doc.addEventListener('DOMContentLoaded', function(e) { |
| | | doc.body.style.fontSize = 12 * dpr + 'px'; |
| | | }, false); |
| | | } |
| | | |
| | | |
| | | refreshRem(); |
| | | |
| | | flexible.dpr = win.dpr = dpr; |
| | | flexible.refreshRem = refreshRem; |
| | | flexible.rem2px = function(d) { |
| | | var val = parseFloat(d) * this.rem; |
| | | if (typeof d === 'string' && d.match(/rem$/)) { |
| | | val += 'px'; |
| | | } |
| | | return val; |
| | | } |
| | | flexible.px2rem = function(d) { |
| | | var val = parseFloat(d) / this.rem; |
| | | if (typeof d === 'string' && d.match(/px$/)) { |
| | | val += 'rem'; |
| | | } |
| | | return val; |
| | | } |
| | | |
| | | })(window, window['lib'] || (window['lib'] = {})); |
| | | |