source: Dev/trunk/src/client/dojox/string/BidiComplex.js

// summary:
//              BiDiComplex module handles complex expression issues known when using BiDi characters
//              in File Paths, URLs, E-mail Address, XPATH, etc.
//              this module adds property listeners to the text fields to correct the text representation
//              in both static text and dynamic text during user input.

define(["dojo/_base/kernel", "dojo/_base/lang", "dojo/_base/array", "dojo/_base/connect", "dojo/_base/sniff",
                "dojo/keys"], 
  function(dojo, lang, arr, hub, has, keys){
        dojo.experimental("dojox.string.BidiComplex");
        var bdc = lang.getObject("string.BidiComplex", true, dojox);

        var _str0 = []; //FIXME: shared reference here among various functions means the functions can't be reused

        bdc.attachInput = function(/*DOMNode*/field, /*String*/pattern){
                // summary:
                //              Attach key listeners to the INPUT field to accomodate dynamic complex BiDi expressions
                // field: INPUT DOM node
                // pattern: Complex Expression Pattern type. One of "FILE_PATH", "URL", "EMAIL", "XPATH"

                field.alt = pattern;

                hub.connect(field, "onkeydown",  this, "_ceKeyDown");
                hub.connect(field, "onkeyup", this, "_ceKeyUp");

                hub.connect(field, "oncut", this, "_ceCutText");
                hub.connect(field, "oncopy", this, "_ceCopyText");

                field.value = bdc.createDisplayString(field.value, field.alt);
        };
                
        bdc.createDisplayString = function(/*String*/str, /*String*/pattern){
                // summary:
                //              Create the display string by adding the Unicode direction Markers
                // pattern: Complex Expression Pattern type. One of "FILE_PATH", "URL", "EMAIL", "XPATH"

                str = bdc.stripSpecialCharacters(str);
                var segmentsPointers = bdc._parse(str, pattern);
                
                var buf = '\u202A'/*LRE*/ + str;
                var shift = 1;
                arr.forEach(segmentsPointers, function(n){
                        if(n != null){
                                var preStr = buf.substring(0, n + shift);
                                var postStr = buf.substring(n + shift, buf.length);
                                buf = preStr + '\u200E'/*LRM*/ + postStr;
                                shift++;
                        }
                });
                return buf;
        };

        bdc.stripSpecialCharacters = function(str){
                // summary:
                //              removes all Unicode directional markers from the string

                return str.replace(/[\u200E\u200F\u202A-\u202E]/g, ""); // String
        };

        bdc._ceKeyDown = function(event){
                var elem = has("ie") ? event.srcElement : event.target;
                _str0 = elem.value;
        };
                                
        bdc._ceKeyUp = function(event){
                var LRM = '\u200E';
                var elem = has("ie") ? event.srcElement : event.target;

                var str1 = elem.value;
                var ieKey = event.keyCode;
                
                if((ieKey == keys.HOME)
                        || (ieKey == keys.END)
                        || (ieKey == keys.SHIFT)){
                        return;
                }

                var cursorStart, cursorEnd;
                var selection = bdc._getCaretPos(event, elem);
                if(selection){
                        cursorStart = selection[0];
                        cursorEnd = selection[1];
                }

        //Jump over a cursor processing
                if(has("ie")){
                        var cursorStart1 = cursorStart, cursorEnd1 = cursorEnd;

                        if(ieKey == keys.LEFT_ARROW){
                                if((str1.charAt(cursorEnd-1) == LRM)
                                                && (cursorStart == cursorEnd)){
                                        bdc._setSelectedRange(elem,cursorStart - 1, cursorEnd - 1);
                                }
                                return;
                        }

                        if(ieKey == keys.RIGHT_ARROW){
                                if(str1.charAt(cursorEnd-1) == LRM){
                                        cursorEnd1 = cursorEnd + 1;
                                        if(cursorStart == cursorEnd){
                                                cursorStart1 = cursorStart + 1;
                                        }
                                }

                                bdc._setSelectedRange(elem, cursorStart1, cursorEnd1);
                                return;
                        }
                }else{ //Firefox
                        if(ieKey == keys.LEFT_ARROW){
                                if(str1.charAt(cursorEnd-1) == LRM){
                                        bdc._setSelectedRange(elem, cursorStart - 1, cursorEnd - 1);
                                }
                                return;
                        }
                        if(ieKey == keys.RIGHT_ARROW){
                                if(str1.charAt(cursorEnd-1) == LRM){
                                        bdc._setSelectedRange(elem, cursorStart + 1, cursorEnd + 1);
                                }
                                return;
                        }
                }
                
                var str2 = bdc.createDisplayString(str1, elem.alt);

                if(str1 != str2)
                {
                        window.status = str1 + " c=" + cursorEnd;
                        elem.value = str2;

                        if((ieKey == keys.DELETE) && (str2.charAt(cursorEnd)==LRM)){
                                elem.value = str2.substring(0, cursorEnd) + str2.substring(cursorEnd+2, str2.length);
                        }

                        if(ieKey == keys.DELETE){
                                bdc._setSelectedRange(elem,cursorStart,cursorEnd);
                        }else if(ieKey == keys.BACKSPACE){
                                if((_str0.length >= cursorEnd) && (_str0.charAt(cursorEnd-1)==LRM)){
                                        bdc._setSelectedRange(elem, cursorStart - 1, cursorEnd - 1);
                                }else{
                                        bdc._setSelectedRange(elem, cursorStart, cursorEnd);
                                }
                        }else if(elem.value.charAt(cursorEnd) != LRM){
                                bdc._setSelectedRange(elem, cursorStart + 1, cursorEnd + 1);
                        }
                }
        };

        bdc._processCopy = function(elem, text, isReverse){
                // summary:
                //              This function strips the unicode directional controls when the text copied to the Clipboard

                if(text == null){
                        if(has("ie")){
                                var range = document.selection.createRange();
                                text = range.text;
                        }else{
                                text = elem.value.substring(elem.selectionStart, elem.selectionEnd);
                        }
                }

                var textToClipboard = bdc.stripSpecialCharacters(text);
        
                if(has("ie")){
                        window.clipboardData.setData("Text", textToClipboard);
                }
                return true;
        };

        bdc._ceCopyText = function(elem){
                if(has("ie")){
                        elem.returnValue = false;
                }
                return bdc._processCopy(elem, null, false);
        };

        bdc._ceCutText = function(elem){

                var ret = bdc._processCopy(elem, null, false);
                if(!ret){
                        return false;
                }

                if(has("ie")){
        //              curPos = elem.selectionStart;
                        document.selection.clear();
                }else{
                        var curPos = elem.selectionStart;
                        elem.value = elem.value.substring(0, curPos) + elem.value.substring(elem.selectionEnd);
                        elem.setSelectionRange(curPos, curPos);
                }

                return true;
        };

        // is there dijit code to do this?
        bdc._getCaretPos = function(event, elem){
                if(has("ie")){
                        var position = 0,
                        range = document.selection.createRange().duplicate(),
                        range2 = range.duplicate(),
                        rangeLength = range.text.length;

                        if(elem.type == "textarea"){
                                range2.moveToElementText(elem);
                        }else{
                                range2.expand('textedit');
                        }
                        while(range.compareEndPoints('StartToStart', range2) > 0){
                                range.moveStart('character', -1);
                                ++position;
                        }

                        return [position, position + rangeLength];
                }

                return [event.target.selectionStart, event.target.selectionEnd];
        };

        // is there dijit code to do this?
        bdc._setSelectedRange = function(elem,selectionStart,selectionEnd){
                if(has("ie")){
                        var range = elem.createTextRange();
                        if(range){
                                if(elem.type == "textarea"){
                                        range.moveToElementText(elem);
                                }else{
                                        range.expand('textedit');
                                }

                                range.collapse();
                                range.moveEnd('character', selectionEnd);
                                range.moveStart('character', selectionStart);
                                range.select();
                        }
                }else{
                        elem.selectionStart = selectionStart;
                        elem.selectionEnd = selectionEnd;
                }
        };

        var _isBidiChar = function(c){
                return (c >= '\u0030' && c <= '\u0039') || (c > '\u00ff');
        };

        var _isLatinChar = function(c){
                return (c >= '\u0041' && c <= '\u005A') || (c >= '\u0061' && c <= '\u007A');
        };

        var _isCharBeforeBiDiChar = function(buffer, i, previous){
                while(i > 0){
                        if(i == previous){
                                return false;
                        }
                        i--;
                        if(_isBidiChar(buffer.charAt(i))){
                                return true;
                        }
                        if(_isLatinChar(buffer.charAt(i))){
                                return false;
                        }
                }
                return false;
        };


        bdc._parse = function(/*String*/str, /*String*/pattern){
                var previous = -1, segmentsPointers = [];
                var delimiters = {
                        FILE_PATH: "/\\:.",
                        URL: "/:.?=&#",
                        XPATH: "/\\:.<>=[]",
                        EMAIL: "<>@.,;"
                }[pattern];

                switch(pattern){
                        case "FILE_PATH":
                        case "URL":
                        case "XPATH":
                                arr.forEach(str, function(ch, i){
                                        if(delimiters.indexOf(ch) >= 0 && _isCharBeforeBiDiChar(str, i, previous)){
                                                previous = i;
                                                segmentsPointers.push(i);
                                        }
                                });
                                break;
                        case "EMAIL":
                                var inQuotes = false; // FIXME: unused?
        
                                arr.forEach(str, function(ch, i){
                                        if(ch== '\"'){
                                                if(_isCharBeforeBiDiChar(str, i, previous)){
                                                        previous = i;
                                                        segmentsPointers.push(i);
                                                }
                                                i++;
                                                var i1 = str.indexOf('\"', i);
                                                if(i1 >= i){
                                                        i = i1;
                                                }
                                                if(_isCharBeforeBiDiChar(str, i, previous)){
                                                        previous = i;
                                                        segmentsPointers.push(i);
                                                }
                                        }
        
                                        if(delimiters.indexOf(ch) >= 0 && _isCharBeforeBiDiChar(str, i, previous)){
                                                                previous = i;
                                                                segmentsPointers.push(i);
                                        }
                                });
                }
                return segmentsPointers;
        };
        return bdc;
});