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Javascript实现语法分色编辑器

　　最近一段时间忽然想到用javascript理论上可以实现一个复杂的在线编辑器，完全能够支持词法、语法方面的功能，于是试验了一下...效率和简易程度还是令人吃惊的，看来javascript比想象的还要强大...

<html>
 <head>
  <title>Silverna Demo Ver 0.01</title>
  <style>
   div.editbox{
    margin:0 0 0 0;
    padding:0 0 0 0;
    font:16/18px Arial;
    border:0px solid #000000;
   }
   p{
    margin:0 0 0 0;
    padding:0 0 0 0;
   }
  </style>
 </head>

 <body style="margin:0 0 0 0;padding:0 0 0 0;word-break:break-all;overflow-x:hidden" onload="editbox.focus()">
 <div id="editbox" class="editbox" style="width:99%;height:80%;" contentEditable="true" onkeyDown="return KeyDown()" onkeyUp="KeyUp()" onclick="getCursorPosition()">
 </div>
 <select size="10" style="display:none;position:absolute" id="methods" onkeydown="SelectMethod()" onclick="SelMethod(this)">
 </body>
</html>


</select>
<script language=JScript>
var testArray = new Array();
var testDate = new Date();
var testString = "aaa";
var testVal = 1;
var testObj = new myObj;

function myObj()
{
     myObj.prototype.testFunc = function(){};
  this.testProperty = "test";
}
function KeyDown()
{
 //alert(event.altKey);
 if(event.keyCode == 9) //TAB 键
 {
  clipboardData.setData('text','    ');
  event.srcElement.document.execCommand('paste');
  return false;  
 }
 if(event.keyCode == 8) //Backspace 键
 {
  var oSel = document.selection.createRange();
  var offset = event.srcElement.document.selection.createRange();
  offset.moveToPoint(oSel.offsetLeft, oSel.offsetTop);
  offset.moveStart('character', -4);
  if(offset.text.length < 4) return true;
  for (var i = 0; i < offset.text.length; i++)
  {
   if (offset.text.charAt(i) != " ")
   {
    return true;
   }
  }
  offset.select();
  event.srcElement.document.execCommand('Delete');
  return false;  
 }
 return true;
}

function KeyUp()
{
 var oSel, offset;
 if(event.keyCode == 13)
 {
  testStr = event.srcElement.innerText.substring(0, getCursorPosition());
  //alert(testStr);
  var space = "";
  for (var i = testStr.length - 1; i >= 0; i--)
  {
   //alert(testStr.length+":"+testStr.charAt(i) + ":" + space.length);
   if (testStr.charAt(i) == "\n") break;
   if (testStr.charAt(i) == " ")
    space += " ";
   else
    space = "";
  }
  //alert(testStr);
  clipboardData.setData('text',space);
  event.srcElement.document.execCommand('paste');
 }
 oSel = document.selection.createRange();
 var left = oSel.offsetLeft;
 var top = oSel.offsetTop;
    var token = getCurrentToken(event.srcElement);
 var chars = getCursorPosition();

 parseSyntax(event.srcElement);
 offset = event.srcElement.document.selection.createRange();
 offset.moveToPoint(left, top);
 offset.select();

 if(event.keyCode == 190) //.键
 {
  setMethods(token.posTok.slice(0, -1));
 }
}

function parseSyntax(src)  //解析当前文本
{  
 var text = src.innerHTML;
 text = text.replace(/<FONT[^<>]*>/gi, "").replace(/<\/FONT[^<>]*>/gi,"");
 text = text.replace(/<P>/gi, "\xfe").replace(/<\/P>/gi, "\xff");
 text = text.replace(/\&nbsp;/gi, "\xfd");
 text = text.replace(/\r\n/gi,"");
 
 for (var i = 0; i <SyntaxSet.All.length; i++)
 {
  var syntaxes = SyntaxSet.All[i];
  for (var j = 0; j < syntaxes.rules.All.length; j++)
  {
   syntaxes.rules.All[j].color = syntaxes.color;
   syntaxes.rules.All[j].cons = syntaxes.cons;

   text = parseRule(text, syntaxes.rules.All[j]);
  }
 }

 src.innerHTML = text.replace(/\xfc/g,"'").replace(/\xfe/g,"<P>").replace(/\xff/g,"</P>").replace(/\xfd/g,"&nbsp;");
}
function parseRule(text, rule)  //解析词法
{
 //利用正则表达式
 var newText = "";

 var idx = text.search(rule.expr);

 while (idx != -1)
 {
  var remark = text.match(rule.expr);
  //alert(text.substring(0, idx+remark[0].length));
  var subText = text.substring(0, idx + remark[0].length);

  if(rule.cons == null || (idx == 0 || rule.cons.test(text.charAt(idx-1))) && (idx + remark[0].length >= text.length || rule.cons.test(text.charAt(idx + remark[0].length))))
  {
   //alert(remark[0]);
   //alert(remark[0].replace(/<FONT[^<>]*>/gi, "").replace(/<\/FONT[^<>]*>/gi,""));
   subText = subText.replace(remark[0], "<FONT color=\xfc"+rule.color+"\xfc>" + remark[0].replace(/<FONT[^<>]*>/gi, "").replace(/<\/FONT[^<>]*>/gi,"") + "</FONT>");
   //alert(subText);
  }
  newText += subText;
  text = text.substring(idx + remark[0].length);
  idx = text.search(rule.expr);
 }
 newText += text;
 return newText;
}

function getCurrentToken(src)
{
 var oSel = document.selection.createRange();
 var offset = src.document.selection.createRange();
 offset.moveToPoint(oSel.offsetLeft, oSel.offsetTop);
 offset.moveStart("character", -99999);

 var tokens = offset.text.split(/[\s\+\-\*\/]/);  //token由连续字母数字、下划线、点号、括号、引号构成
 var currentToken = tokens[tokens.length - 1];

 var idx = offset.text.length;

 var fullToken = src.innerText.substring(idx);
 fullToken = fullToken.replace(/[\s\+\-\*\/]/,"@@@@");

 idx = fullToken.indexOf("@@@@");
 if(idx != -1)
  fullToken = fullToken.substring(0, idx);

 var token = new Array();

 token.currentToken = currentToken + fullToken;
 token.posTok = currentToken;

 return token;
}
Array.prototype.pushDistinct = function(obj)
{
 for (var i = 0; i < this.length; i++)
 {
  if (this[i] == obj)
  {
   return null;
  }
 }
 this.push(obj);
 return obj;
}

function putMethods(methodList, obj, methods)  //将方法添加到方法列表
{
 var list = methods.split(",");

 for (var i = 0; i < list.length; i++)
 {
  if (obj[list[i]] != null)
  {
   methodList.pushDistinct(list[i]);
  }
 }
}
var now = new Date(); //测试用
var a = 33.3333; //测试用
var __expr = new RegExp("tt"); //测试用
function setMethods(objStr)
{
  var oSel = document.selection.createRange();

  try
  {
   if (objStr == "alert") return;
   var methodList = new Array();
   var obj = eval(objStr);

   if (obj.prototype != null)
   {
    methodList.pushDistinct("prototype");
   }
   if (obj != null)
   {

    //基本Object方法
    putMethods(methodList, obj,"constructor,hasOwnProperty,isPrototypeOf,propertyIsEnumerable,toLocaleString,toString,valueOf");
    
    //基本Array方法
    putMethods(methodList, obj,"concat,join,length,pop,push,reverse,shift,slice,sort,splice,unshift");     

    //基本Date方法
    putMethods(methodList,obj,"getDate,getUTCDate,getDay,getUTCDay,getFullYear,getUTCFullYear,getHours,getUTCHours,getMilliseconds,getUTCMilliseconds,getMinutes,getUTCMinutes,getMonth,getUTCMonth,getSeconds,getUTCSeconds,getTime,getTimezoneoffset,getYear");

    putMethods(methodList,obj,"setDate,setUTCDate,setFullYear,setUTCFullYear,setHours,setUTCHours,setMilliseconds,setUTCMilliseconds,setMinutes,setUTCMinutes,setMonth,setUTCMonth,setSeconds,setUTCSeconds,setTime,setYear,toDateString,toGMTString,toLocaleDateString,toLocaleTimeString,toString,toTimeString,toUTCString,valueOf,parse,UTC");

    //基本Math方法
    putMethods(methodList,obj,"E,LN10,LN2,LOG10E,LOG2E,PI,SQRT1_2,SQRT2");
    putMethods(methodList,obj,"abs,acos,asin,atan,atan2,ceil,cos,exp,floor,log,max,min,pow,random,round,sin,sqrt,tan");

    //基本Function方法
    putMethods(methodList,obj,"arguments,caller,length,prototype,apply,call,toString");
    
    //基本Number方法
    putMethods(methodList,obj,"MAX_VALUE,MIN_VALUE,NaN,NEGATIVE_INFINITY,POSITIVE_INFINITY");
    putMethods(methodList,obj,"toString,toLocalString,toFixed,toExponential,toPrecision");

    //基本RegExp方法
    putMethods(methodList,obj,"global,ignoreCase,lastIndex,multiline,source,exec,test");

    //基本String方法
    putMethods(methodList,obj,"charAt,charCodeAt,contact,indexOf,lastIndexOf,match,replace,search,slice,split,substring,substr,toLowerCase,toString,toUpperCase,valueOf,fromCharCode");
    putMethods(methodList,obj,"anchor,big,blink,bold,fixed,fontcolor,fontsize,italics,link,small,strike,sub,sup");

   }
   for (each in obj)
   {
    methodList.pushDistinct(each);
   }
   methodList.sort();

   if (methodList.length > 0)
   {
    methods.options.length = 0;
    for (var i = 0; i < methodList.length; i++)
    {
     methods.options.add(new Option(methodList[i])); 
    }
    if (methods.options.length > 10)
    {
     methods.size = 10;
    }
    else
    {
     methods.size = methods.options.length;
    }
    methods.style.top = oSel.offsetTop;
    methods.style.left = oSel.offsetLeft;
    methods.style.display = "";
    methods.options[0].selected = true;
    methods.focus();
   }
  }
  catch(e){}
}

function SelectMethod()
{
 var src = event.srcElement;
 if(event.keyCode == 13)
 {
  SelMethod(src);
 }

 if(event.keyCode == 27 || event.keyCode == 8 || event.keyCode == 32)
 {
  src.style.display = "none";
  editbox.focus();
 }
}

function SelMethod(src)
{
 clipboardData.setData('text',src.options[src.selectedIndex].text);
 editbox.focus();
 editbox.document.execCommand('paste');
 src.style.display = "none";
 getCursorPosition();
}
function getPos(text) //计算行数、列数
{
 var rows = 1;
 var cols = 1;
 var idx = 0;
 var subText = text;
 while((idx = subText.indexOf("\n")) != -1)
 {
  subText = subText.substring(idx + 1);
  rows++;
 }
 return new Array(rows, subText.length + 1);
}
function getNullRows(src,oSel) //计算空行
{
 var rows = 0;

 var offsetEnd = src.document.selection.createRange();

 var oldTop = 2;
 var oldLeft = 2;

 while(1)
 {
  offsetEnd.moveToPoint(oSel.offsetLeft, oSel.offsetTop);
  offsetEnd.moveStart("character",-1-rows);

  if (offsetEnd.text.length > 0 || offsetEnd.offsetTop == oldTop && offsetEnd.offsetLeft == oldLeft)
  {
   break;
  }

  rows ++;
  oldTop = offsetEnd.offsetTop;
  oldLeft = offsetEnd.offsetLeft;
 }
 
 return rows;
}
function getCursorPosition()
{
 var src = event.srcElement;
 var offset = src.document.selection.createRange();
 var oSel = document.selection.createRange();

 var textLength = src.innerText.length;

 offset.moveToPoint(oSel.offsetLeft, oSel.offsetTop);
 offset.moveStart("character", -99999);
 //src.document.execCommand("ForeColor",false,"#ff0000");
 var rowSpans = offset.getClientRects();

 var pos = getPos(offset.text);
 
 var charCodes = offset.text.length; //字符总数
 var chars = offset.text.replace(/\r\n/g,"").length + 1; //字符

 var extRows = getNullRows(src,oSel);
 if(extRows > 0)
 {
  pos[0] += extRows;
  pos[1] = 1;
 }
 window.status = "行: " + pos[0] +", 列: " + pos[1] + ", 第 " + chars + " 个字符" + "  ("+ oSel.offsetTop +","+
 oSel.offsetLeft +")";
 return charCodes;
}


///词法解析过程................................................................................
///............................................................................................
///............................................................................................

var SyntaxSet = new Array(); //词法规则集合
SyntaxSet.All = new Array();

SyntaxSet.parse = function(token)   //针对token返回rule
{
 for (var i = 0; i < this.All.length; i++)
 {
  var syntaxes = this.All[i];
  for (var j = 0; j < syntaxes.rules.All.length; j++)
  {
   if (syntaxes.rules.All[j].test(token))
   {
    syntaxes.rules.All[j].color = syntaxes.color;
    return syntaxes.rules.All[j];
   }
  }
 }

 return null;
}

SyntaxSet.add = function(syntaxes)
{
 if(this[syntaxes.name] != null)
  return;
 this[syntaxes.name] = syntaxes;
 this.All.push(syntaxes);
}

function Syntaxes(name, color, cons) //词法规则组（同组规则用一种颜色标记）
{
 this.name = name; //规则组名称
 this.color = color;  //标记该语法的颜色
 this.rules = new Array();  //语法规则（以次序决定优先级）
 this.rules.All = new Array();
 this.cons = cons;  //边界约束


 Syntaxes.prototype.addRule = function(rule)
 {
  if(this.rules[rule.name] != null)
   return;
  this.rules[rule.name] = rule;
  this.rules.All.push(rule);
 }
}

function SyntaxRule(name, regExp)  //词法规则
{
 this.name = name;    //规则名称
    this.expr = regExp;  //规则描述 (正则表达式)
 SyntaxRule.prototype.test = function(token)
 {
  return this.expr.test(token);
 }
}

function RegExprX(exprStr)  //扩展正则表达式的功能，支持定义嵌套
{
 this.expr = exprStr;
}
RegExprX.prototype.getPattern = function(tag)  //获取正则表达式对象
{
 if (tag == null)
  return new RegExp(this.expr);
 else
  return new RegExp(this.expr, tag);
}
RegExprX.prototype.concat = function(expr, rule)  //连接两个正则表达式串
{
 if (rule == null)
  this.expr += expr;  //直接连接
 else if (rule == "union")  //联合
  this.expr = "(" + this.expr + ")" + "|" + "(" + expr + ")"; 
 else if (rule == "cons") //约束
  this.expr = this.expr + "(?=" + expr + ")";
 return this.expr;
}

//为保证正确计算偏移量需要替换回车\n\r为\xff
SyntaxSet.add(new Syntaxes("keywords", "#0000ff", /[\s\.\xfe\xff\xfd\(\{\}\)\;\,]/));  //词法?关键词?蓝色
SyntaxSet["keywords"].addRule(new SyntaxRule("Function",/function/));
SyntaxSet["keywords"].addRule(new SyntaxRule("Variable",/var/));
SyntaxSet["keywords"].addRule(new SyntaxRule("Return",/return/));
SyntaxSet["keywords"].addRule(new SyntaxRule("Exception",/(try|catch|throw)/));
SyntaxSet["keywords"].addRule(new SyntaxRule("Condition",/(if|else|switch)/));
SyntaxSet["keywords"].addRule(new SyntaxRule("Cycle",/(for|while|do)/));
SyntaxSet["keywords"].addRule(new SyntaxRule("Type",/(int|double|float|void|char)/));
SyntaxSet["keywords"].addRule(new SyntaxRule("Right",/(public|private|protected|static)/));
SyntaxSet["keywords"].addRule(new SyntaxRule("Constant",/(null|undefined|NaN|Infinity)/));
SyntaxSet["keywords"].addRule(new SyntaxRule("Construct",/(new|delete)/));

SyntaxSet.add(new Syntaxes("objects", "#FF0000", /[\s\.\xfe\xff\xfd\(\{\}\)\;\,]/));  //词法?对象?红色
SyntaxSet["objects"].addRule(new SyntaxRule("Object",/(Array|arguments|Boolean|Date|Error|Function|Object|Number|Math|RegExp|String)/));

SyntaxSet.add(new Syntaxes("global", "#800000", /[\s\.\xfe\xff\xfd\(\{\}\)\;\,]/));  //词法?系统函数?红色
SyntaxSet["global"].addRule(new SyntaxRule("SystemFunc",/(alert|parseFloat|parseInt|eval|decodeURI|decodeURIComponent|encodeURI|encodeURIComponent|escape|eval|isFinite|isNaN|unescape)/));

SyntaxSet.add(new Syntaxes("String", "#ff00ff", /[\s\.\xfe\xff\xfd\(\{\}\)\;\,\+\-\*\/]/));  //词法?字符串?粉色
SyntaxSet["String"].addRule(new SyntaxRule("String",
       /('((\\\')|[^\xff\'])*([^\\\']|(\\\'))')|("((\\\")|[^\xff\"])*([^\\\"]|(\\\"))")/));

SyntaxSet.add(new Syntaxes("remarks", "#008000")); //词法?注释?绿色
SyntaxSet["remarks"].addRule(new SyntaxRule("ShortRemark",/\/\/[^\xff]*/));
SyntaxSet["remarks"].addRule(new SyntaxRule("LongRemark",/\/\*((.*\*\/)|(.*$))/));

function Grammars() //语法规则
{
}
</script>

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