javascript 精確擷取樣式屬性（下）

複製代碼 代碼如下:var rgb2hex = function(rgb) {
rgb = rgb.match(/^rgb\((\d+),\s*(\d+),\s*(\d+)\)$/);
return "#"+tohex(rgb[1])+tohex(rgb[2])+tohex(rgb[3])
}
var tohex = function(x) {
var hexDigits = ['0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'];
return isNaN(x) ? '00' : hexDigits[(x - x % 16) / 16] + hexDigits[x % 16];
}

我們用Regex在檢測其是否為rgb格式，是就用rgb2hex來轉換它。但如果是red，green等值呢，Firefox就一反常態，轉換為hex格式，但IE依然如故。我們沒有辦法，自己做一個雜湊，把常用的顏色都弄進去，然後一一匹對便是。 複製代碼 代碼如下:if(style.search(/background|color/) != -1) {
var color = {
aqua: '#0ff',
black: '#000',
blue: '#00f',
gray: '#808080',
purple: '#800080',
fuchsia: '#f0f',
green: '#008000',
lime: '#0f0',
maroon: '#800000',
navy: '#000080',
olive: '#808000',
orange:'#ffa500',
red: '#f00',
silver: '#c0c0c0',
teal: '#008080',
transparent:'rgba(0,0,0,0)',
white: '#fff',
yellow: '#ff0'
}
if(!!color[value]){
value = color[value]
}
if(value == "inherit"){
return getStyle(el.parentNode,style);
}
if(/^rgb\((\d+),\s*(\d+),\s*(\d+)\)$/.test(value)){
return rgb2hex(value)
}else if(/^#/.test(value)){
value = value.replace('#', '');
return "#" + (value.length == 3 ? value.replace(/^(\w)(\w)(\w)$/, '$1$1$2$2$3$3') : value);
}
return value;
}

基本上是對於CSS的精確取值就是這樣，顯然它還存在許多不足之處，但對於布局用的和常用的樣式都實現了。還提供了一個判斷頁面渲染模式的常數q，為了方便，方法名與JQuery同名（只能取值，不能賦值，以後有空慢慢與我的addSheet函數整合到一起）。 複製代碼 代碼如下:(function(){
var isQuirk = (document.documentMode) ? (document.documentMode==5) ? true : false : ((document.compatMode=="CSS1Compat") ? false : true);
var isElement = function(el) {
return !!(el && el.nodeType == 1);
}
var propCache = [];
var propFloat = !+"\v1" ? 'styleFloat' : 'cssFloat';
var camelize = function(attr){
return attr.replace(/\-(\w)/g, function(all, letter){
return letter.toUpperCase();
});
}
var memorize = function(prop) { //意思為：check out form cache
return propCache[prop] || (propCache[prop] = prop == 'float' ? propFloat : camelize(prop));
}
var getIEOpacity = function(el){
var filter;
if(!!window.XDomainRequest){
filter = el.style.filter.match(/progid:DXImageTransform.Microsoft.Alpha\(.?opacity=(.*).?\)/i);
}else{
filter = el.style.filter.match(/alpha\(opacity=(.*)\)/i);
}
if(filter){
var value = parseFloat(filter[1]);
if (!isNaN(value)) {
return value ? value / 100 : 0;
}
}
return 1;
}
var convertPixelValue = function(el, value){
var style = el.style,left = style.left,rsLeft = el.runtimeStyle.left;
el.runtimeStyle.left = el.currentStyle.left;
style.left = value || 0;
var px = style.pixelLeft;
style.left = left;//還原資料
el.runtimeStyle.left = rsLeft;//還原資料
return px + "px"
}
var rgb2hex = function(rgb) {
rgb = rgb.match(/^rgb\((\d+),\s*(\d+),\s*(\d+)\)$/);
return "#"+tohex(rgb[1])+tohex(rgb[2])+tohex(rgb[3])
}
var tohex = function(x) {
var hexDigits = ['0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'];
return isNaN(x) ? '00' : hexDigits[(x - x % 16) / 16] + hexDigits[x % 16];
}
var getStyle = function (el, style){
var value;
if(!+"\v1"){
//特殊處理IE的opacity
if(style == "opacity"){
return getIEOpacity(el)
}
value = el.currentStyle[memorize(style)];
//特殊處理IE的height與width
if (/^(height|width)$/.test(style)){
var values = (style == 'width') ? ['left', 'right'] : ['top', 'bottom'], size = 0;
if(isQuirk){
return el[camelize("offset-"+style)] + "px"
}else{
var client = parseFloat(el[camelize("client-"+style)]),
paddingA = parseFloat(getStyle(el, "padding-"+ values[0])),
paddingB = parseFloat(getStyle(el, "padding-"+ values[1]));
return (client - paddingA - paddingB)+"px";
}
}
}else{
if(style == "float"){
style = propFloat;
}
value = document.defaultView.getComputedStyle(el, null).getPropertyValue(style)
}
//下面部分全部用來轉換上面得出的非精確值
if(!/^\d+px$/.test(value)){
//轉換可度量的值
if(/(em|pt|mm|cm|pc|in|ex|rem|vw|vh|vm|ch|gr)$/.test(value)){
return convertPixelValue(el,value);
}
//轉換百分比，不包括字型
if(/%$/.test(value) && style != "font-size"){
return parseFloat(getStyle(el.parentNode,"width")) * parseFloat(value) /100 + "px"
}
//轉換border的thin medium thick
if(/^(border).+(width)$/.test(style)){
var s = style.replace("width","style"),
b = {
thin:["1px","2px"],
medium:["3px","4px"],
thick:["5px","6px"]
};
if(value == "medium" && getStyle(el,s) == "none"){
return "0px";
}
return !!window.XDomainRequest ? b[value][0] : b[value][1];
}
//轉換margin的auto
if(/^(margin).+/.test(style) && value == "auto"){
var father = el.parentNode;
if(/MSIE 6/.test(navigator.userAgent) && getStyle(father,"text-align") == "center"){
var fatherWidth = parseFloat(getStyle(father,"width")),
_temp = getStyle(father,"position");
father.runtimeStyle.postion = "relative";
var offsetWidth = el.offsetWidth;
father.runtimeStyle.postion = _temp;
return (fatherWidth - offsetWidth)/2 + "px";
}
return "0px";
}
//轉換top|left|right|bottom的auto
if(/(top|left|right|bottom)/.test(style) && value == "auto"){
return el.getBoundingClientRect()[style];
}
//轉換顏色
if(style.search(/background|color/) != -1) {
var color = {
aqua: '#0ff',
black: '#000',
blue: '#00f',
gray: '#808080',
purple: '#800080',
fuchsia: '#f0f',
green: '#008000',
lime: '#0f0',
maroon: '#800000',
navy: '#000080',
olive: '#808000',
orange:'#ffa500',
red: '#f00',
silver: '#c0c0c0',
teal: '#008080',
transparent:'rgba(0,0,0,0)',
white: '#fff',
yellow: '#ff0'
}
if(!!color[value]){
value = color[value]
}
if(value == "inherit"){
return getStyle(el.parentNode,style);
}
if(/^rgb\((\d+),\s*(\d+),\s*(\d+)\)$/.test(value)){
return rgb2hex(value)
}else if(/^#/.test(value)){
value = value.replace('#', '');
return "#" + (value.length == 3 ? value.replace(/^(\w)(\w)(\w)$/, '$1$1$2$2$3$3') : value);
}
return value;
}
}
return value;//如 0px
}
var css = function(){
var a = arguments;
if(a.length == 1){
return getStyle(this,a[0])
}
}
var _ = function(el){
var el = isElement(el)? el :document.getElementById(el);
var gene = !el.constructor ? el : el.constructor.prototype;
gene.css = css;
gene.width = function(){
return getStyle(this,"width");
};
gene.height = function(){
return getStyle(this,"height");
};
return el
}
if(!window._){ //為了避免與JQuery的$發生衝突，我用_作為類庫唯一的全域變數
window['_'] =_;
}
_.q = isQuirk;
})()

用法如下： 複製代碼 代碼如下:window.onload = function(){
alert(_("ccc").css("background-color"))
alert(_("aaa").css("width"))
alert(_(document.body).width())
};

我們可以用這個東西研究一下document.body與document.documentElement。 複製代碼 代碼如下:function text(){
var body = document.body,html = document.documentElement;
_("w1").innerHTML = _(body).width();
_("w2").innerHTML = _(html).width();
_("h1").innerHTML = _(body).height();
_("h2").innerHTML = _(html).height();
_("ml1").innerHTML = _(body).css("margin-left");
_("ml2").innerHTML = _(html).css("margin-left");
_("mr1").innerHTML = _(body).css("margin-right");
_("mr2").innerHTML = _(html).css("margin-right");
_("mt1").innerHTML = _(body).css("margin-top");
_("mt2").innerHTML = _(html).css("margin-top");
_("mb1").innerHTML = _(body).css("margin-bottom");
_("mb2").innerHTML = _(html).css("margin-bottom");
_("pl1").innerHTML = _(body).css("padding-left");
_("pl2").innerHTML = _(html).css("padding-left");
_("pr1").innerHTML = _(body).css("padding-right");
_("pr2").innerHTML = _(html).css("padding-right");
_("bl1").innerHTML = _(body).css("border-left-width");
_("bl2").innerHTML = _(html).css("border-left-width");
_("br1").innerHTML = _(body).css("border-right-width");
_("br2").innerHTML = _(html).css("border-right-width");
_("qqq").innerHTML = !_.q ? "標準模式" : "怪癖模式";
_("t1").innerHTML = _(body).css("top");
_("t2").innerHTML = _(html).css("top");
_("l1").innerHTML = _(body).css("left");
_("l2").innerHTML = _(html).css("left");
_("ot1").innerHTML = body.offsetTop;
_("ot2").innerHTML = html.offsetTop;
_("ol1").innerHTML = body.offsetLeft;
_("ol2").innerHTML = html.offsetLeft;
_("ct1").innerHTML = body.clientTop;
_("ct2").innerHTML = html.clientTop;
_("cl1").innerHTML = body.clientLeft;
_("cl2").innerHTML = html.clientLeft;
_("cw1").innerHTML = body.clientWidth;
_("cw2").innerHTML = html.clientWidth;
_("ow1").innerHTML = body.offsetWidth;
_("ow2").innerHTML = html.offsetWidth;
_("sw1").innerHTML = body.scrollWidth;
_("sw2").innerHTML = html.scrollWidth;
}

dir="ltr" lang="zh-CN" id="html">

測試屬性	document.body	document.documentElement
width
height
margin-left
margin-right
margin-top
margin-bottom
padding-left
padding-right
border-left-width
border-right-width
渲染模式
top
left
offsetTop
offsetLeft
clientTop
clientLeft
offsetWidth
clientWidth
scrollWidth

運行代碼