jQuery第三十一天练习
DD_belatedPNG.js /** * DD_belatedPNG: Adds IE6 support: PNG images for CSS background-image and HTML
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. * Author: Drew Diller * Email: drew.diller@gmail.com * URL: http://www.dillerdesign.com/experiment/DD_belatedPNG/ * Version: 0.0.8a * Licensed under the MIT License: http://dillerdesign.com/experiment/DD_belatedPNG/#license * * Example usage: * DD_belatedPNG.fix(＂.png_bg＂); // argument is a CSS selector * DD_belatedPNG.fixPng( someNode ); // argument is an HTMLDomElement **/ /* PLEASE READ: Absolutely everything in this script is SILLY. I know this. IE＂s rendering of certain pixels doesn＂t make sense, so neither does this code! */ var DD_belatedPNG = { ns: ＂DD_belatedPNG＂, imgSize: {}, delay: 10, nodesFixed: 0, createVmlNameSpace: function () { /* enable VML */ if (document.namespaces && !document.namespaces[this.ns]) { document.namespaces.add(this.ns, ＂urn:schemas-microsoft-com:vml＂); } }, createVmlStyleSheet: function () { /* style VML, enable behaviors */ /* Just in case lots of other developers have added lots of other stylesheets using document.createStyleSheet and hit the 31-limit mark, let＂s not use that method! further reading: http://msdn.microsoft.com/en-us/library/ms531194(VS.85).aspx */ var screenStyleSheet, printStyleSheet; screenStyleSheet = document.createElement(＂style＂); screenStyleSheet.setAttribute(＂media＂, ＂screen＂); document.documentElement.firstChild.insertBefore(screenStyleSheet, document.documentElement.firstChild.firstChild); if (screenStyleSheet.styleSheet) { screenStyleSheet = screenStyleSheet.styleSheet; screenStyleSheet.addRule(this.ns + ＂:*＂, ＂{behavior:url(#default#VML)}＂); screenStyleSheet.addRule(this.ns + ＂:shape＂, ＂position:absolute;＂); screenStyleSheet.addRule(＂img.＂ + this.ns + ＂_sizeFinder＂, ＂behavior:none; border:none; position:absolute; z-index:-1; top:-10000px; visibility:hidden;＂); /* large negative top value for avoiding vertical scrollbars for large images, suggested by James O＂Brien, http://www.thanatopsic.org/hendrik/ */ this.screenStyleSheet = screenStyleSheet; /* Add a print-media stylesheet, for preventing VML artifacts from showing up in print (including preview). */ /* Thanks to R�mi Pr�vost for automating this! */ printStyleSheet = document.createElement(＂style＂); printStyleSheet.setAttribute(＂media＂, ＂print＂); document.documentElement.firstChild.insertBefore(printStyleSheet, document.documentElement.firstChild.firstChild); printStyleSheet = printStyleSheet.styleSheet; printStyleSheet.addRule(this.ns + ＂:*＂, ＂{display: none !important;}＂); printStyleSheet.addRule(＂img.＂ + this.ns + ＂_sizeFinder＂, ＂{display: none !important;}＂); } }, readPropertyChange: function () { var el, display, v; el = event.srcElement; if (!el.vmlInitiated) { return; } if (event.propertyName.search(＂background＂) != -1 || event.propertyName.search(＂border＂) != -1) { DD_belatedPNG.applyVML(el); } if (event.propertyName == ＂style.display＂) { display = (el.currentStyle.display == ＂none＂) ? ＂none＂ : ＂block＂; for (v in el.vml) { if (el.vml.hasOwnProperty(v)) { el.vml[v].shape.style.display = display; } } } if (event.propertyName.search(＂filter＂) != -1) { DD_belatedPNG.vmlOpacity(el); } }, vmlOpacity: function (el) { if (el.currentStyle.filter.search(＂lpha＂) != -1) { var trans = el.currentStyle.filter; trans = parseInt(trans.substring(trans.lastIndexOf(＂=＂)+1, trans.lastIndexOf(＂)＂)), 10)/100; el.vml.color.shape.style.filter = el.currentStyle.filter; /* complete guesswork */ el.vml.image.fill.opacity = trans; /* complete guesswork */ } }, handlePseudoHover: function (el) { setTimeout(function () { /* wouldn＂t work as intended without setTimeout */ DD_belatedPNG.applyVML(el); }, 1); }, /** * This is the method to use in a document. * @param {String} selector - REQUIRED - a CSS selector, such as ＂#doc .container＂ **/ fix: function (selector) { if (this.screenStyleSheet) { var selectors, i; selectors = selector.split(＂,＂); /* multiple selectors supported, no need for multiple calls to this anymore */ for (i=0; i
size.H) { c.B = size.H; } el.vml.image.shape.style.clip = ＂rect(＂+c.T+＂px ＂+(c.R+fudge)+＂px ＂+c.B+＂px ＂+(c.L+fudge)+＂px)＂; } else { el.vml.image.shape.style.clip = ＂rect(＂+dC.T+＂px ＂+dC.R+＂px ＂+dC.B+＂px ＂+dC.L+＂px)＂; } }, figurePercentage: function (bg, size, axis, position) { var horizontal, fraction; fraction = true; horizontal = (axis == ＂X＂); switch(position) { case ＂left＂: case ＂top＂: bg[axis] = 0; break; case ＂center＂: bg[axis] = 0.5; break; case ＂right＂: case ＂bottom＂: bg[axis] = 1; break; default: if (position.search(＂%＂) != -1) { bg[axis] = parseInt(position, 10) / 100; } else { fraction = false; } } bg[axis] = Math.ceil( fraction ? ( (size[horizontal?＂W＂: ＂H＂] * bg[axis]) - (size[horizontal?＂w＂: ＂h＂] * bg[axis]) ) : parseInt(position, 10) ); if (bg[axis] % 2 === 0) { bg[axis]++; } return bg[axis]; }, fixPng: function (el) { el.style.behavior = ＂none＂; var lib, els, nodeStr, v, e; if (el.nodeName == ＂BODY＂ || el.nodeName == ＂TD＂ || el.nodeName == ＂TR＂) { /* elements not supported yet */ return; } el.isImg = false; if (el.nodeName == ＂IMG＂) { if(el.src.toLowerCase().search(/.png$/) != -1) { el.isImg = true; el.style.visibility = ＂hidden＂; } else { return; } } else if (el.currentStyle.backgroundImage.toLowerCase().search(＂.png＂) == -1) { return; } lib = DD_belatedPNG; el.vml = {color: {}, image: {}}; els = {shape: {}, fill: {}}; for (v in el.vml) { if (el.vml.hasOwnProperty(v)) { for (e in els) { if (els.hasOwnProperty(e)) { nodeStr = lib.ns + ＂:＂ + e; el.vml[v][e] = document.createElement(nodeStr); } } el.vml[v].shape.stroked = false; el.vml[v].shape.appendChild(el.vml[v].fill); el.parentNode.insertBefore(el.vml[v].shape, el); } } el.vml.image.shape.fillcolor = ＂none＂; /* Don＂t show blank white shapeangle when waiting for image to load. */ el.vml.image.fill.type = ＂tile＂; /* Makes image show up. */ el.vml.color.fill.on = false; /* Actually going to apply vml element＂s style.backgroundColor, so hide the whiteness. */ lib.attachHandlers(el); lib.giveLayout(el); lib.giveLayout(el.offsetParent); el.vmlInitiated = true; lib.applyVML(el); /* Render! */ } }; try { document.execCommand(＂BackgroundImageCache＂, false, true); /* TredoSoft Multiple IE doesn＂t like this, so try{} it */ } catch(r) {} DD_belatedPNG.createVmlNameSpace(); DD_belatedPNG.createVmlStyleSheet();
效果图：
