/**
- Trasliteration Tool
- @author Junaid P V (user:Junaidpv)
- @date 2010-05-19
- License: GPLv3, CC-BY-SA 3.0
- /
/**
- Define your own regular expression rules here. Or include predefined rules before this file.
- They should be in associative arrays named 'rules' and 'memrules'
- 'rules' table is for normal rewriting
- 'memrules' table is for memorised rules
- /  
// defining to store state info
var trasliteration_fields = {};
// memory for previus key sequence
var previous_sequence = {};
// temporary disabling of transliteration
var temp_disable = {};
/**
- from: http://stackoverflow.com/questions/3053542/how-to-get-the-start-and-end-points-of-selection-in-text-area/3053640#3053640
- /
function GetCaretPosition(el) {
var start = 0, end = 0, normalizedValue, range,
textInputRange, len, endRange;  
if (typeof el.selectionStart == "number" && typeof el.selectionEnd == "number") {
start = el.selectionStart;
end = el.selectionEnd;
} else {
range = document.selection.createRange;
if (range && range.parentElement == el) {
len = el.value.length;
normalizedValue = el.value.replace(/\r\n/g, "\n");  
// Create a working TextRange that lives only in the input
textInputRange = el.createTextRange;
textInputRange.moveToBookmark(range.getBookmark);  
// Check if the start and end of the selection are at the very end
// of the input, since moveStart/moveEnd doesn't return what we want
// in those cases
endRange = el.createTextRange;
endRange.collapse(false);  
if (textInputRange.compareEndPoints("StartToEnd", endRange) > -1) {
start = end = len;
} else {
start = -textInputRange.moveStart("character", -len);
start += normalizedValue.slice(0, start).split("\n").length - 1;  
if (textInputRange.compareEndPoints("EndToEnd", endRange) > -1) {
end = len;
} else {
end = -textInputRange.moveEnd("character", -len);
end += normalizedValue.slice(0, end).split("\n").length - 1;
}
}
}
}
return {
start: start,
end: end
};
}  
/**
- from: http://stackoverflow.com/questions/3274843/get-caret-position-in-textarea-ie
- /
function offsetToRangeCharacterMove(el, offset) {
return offset - (el.value.slice(0, offset).split("\r\n").length - 1);
}
/**
- IE part from: http://stackoverflow.com/questions/3274843/get-caret-position-in-textarea-ie
- /
function setCaretPosition (el, iCaretPos)
{
if (document.selection) // IE
{
endOffset = startOffset=iCaretPos;
var range = el.createTextRange;
var startCharMove = offsetToRangeCharacterMove(el, startOffset);
range.collapse(true);
if (startOffset == endOffset) {
range.move("character", startCharMove);
} else {
range.moveEnd("character", offsetToRangeCharacterMove(el, endOffset));
range.moveStart("character", startCharMove);
}
range.select;
}
else if (el.selectionStart || el.selectionStart == '0') // Firefox
{
el.setSelectionRange(iCaretPos, iCaretPos)
}
}  
function getLastSixChars(str, caretPosition)
{
if(caretPosition <= 6 ) return str.substring(0,caretPosition);
else return str.substring(caretPosition-6,caretPosition);
}  
function replaceTransStringAtCaret(control, oldStringLength, newString, selectionRange)
{
var text = control.value;
// firefox always scrolls to topmost position,
// to scroll manually we keep original scroll postion.
if(control.scrollTop || control.scrollTop=='0') { var scrollTop = control.scrollTop; }
if(text.length >= 1) {
var firstStr = text.substring(0, selectionRange['start'] - oldStringLength + 1);
var lastStr = text.substring(selectionRange['end'], text.length);
control.value = firstStr+newString+ lastStr;
var newCaretPosition = firstStr.length+newString.length;
setCaretPosition(control,newCaretPosition);
}
else {
control.value = newString;
var newCaretPosition = newString.length;
setCaretPosition(control,newCaretPosition);
}
// Manually scrolling in firefox, few tweeks or re-writing may require
if (navigator.userAgent.indexOf("Firefox")!=-1) {
var textLength = control.value.length;
var cols = control.cols;
if(newCaretPosition > (textLength-cols)) {
//var height = parseInt(window.getComputedStyle(control,null).getPropertyValue('height'));
var fontsize = parseInt(window.getComputedStyle(control,null).getPropertyValue('font-size'));
//var lineheight = height/fontsize;
control.scrollTop = scrollTop+fontsize;
} else control.scrollTop = scrollTop;
}
}  
/**
- This function will take a string to check against regular expression rules in the rules array.
- It will return a two memeber array, having given string as first member and replacement string as
- second memeber. If corresponding replacement could not be found then second string will be too given string
- /
function trans(lastpart,e)
{
var len = lastpart.length;
var i=0;
var part1 = lastpart;
var part2 = lastpart;
var found = false;
outerloop1:
for(i=0; i< len; i++)
{
var toTrans = lastpart.substring(i, len);
for(var key in memrules)
{
if((new RegExp(key)).test(toTrans) && (new RegExp(memrules[key][0])).test(previous_sequence[(e.currentTarget || e.srcElement).id ]))
{
part1 = toTrans;
part2 = toTrans.replace(RegExp(key), memrules[key][1]);
found = true;
break outerloop1;
}
}
}
if(!found)
{
outerloop2:
for(i=0; i< len; i++)
{
var toTrans = lastpart.substring(i, len);
for(var key in rules)
{
if((new RegExp(key)).test(toTrans))
{
part1 = toTrans;
part2 = toTrans.replace(RegExp(key), rules[key]);
break outerloop2;
}
}
}
}
var pair = new Array(part1, part2);
return pair;
}
/**
- from: http://www.javascripter.net/faq/settinga.htm
- /
function setCookie(cookieName,cookieValue,nDays) {
var today = new Date;
var expire = new Date;
if (nDays==null || nDays==0) nDays=1;
expire.setTime(today.getTime + 3600000*24*nDays);
document.cookie = cookieName+"="+escape(cookieValue)+ ";expires="+expire.toGMTString;
}
/**
- from: http://www.javascripter.net/faq/readinga.htm
- /
function readCookie(cookieName) {
var theCookie=""+document.cookie;
var ind=theCookie.indexOf(cookieName);
if (ind==-1 || cookieName=="") return "";
var ind1=theCookie.indexOf(';',ind);
if (ind1==-1) ind1=theCookie.length;
return unescape(theCookie.substring(ind+cookieName.length+1,ind1));
}  
function enableTrasliteration(controlID, enable) {
if(enable==undefined) { enable = true; }
var cookieValue;
if(enable) {
trasliteration_fields[controlID] = true;
temp_disable[controlID] = false;
cookieValue = 1;
}
else {
trasliteration_fields[controlID] = false;
cookieValue = 0;
}
var checkbox = document.getElementById(controlID+'cb');
if(checkbox) { checkbox.checked = enable; }
setCookie("tr"+controlID, cookieValue);
}  
// event listener for trasliterattion textfield
// also listen for Ctrl+M combination to disable and enable trasliteration
function tiKeyPressed(event) {
var e = event || window.event;
var code = e.charCode || e.keyCode;
var targetElement = (e.currentTarget || e.srcElement);
if (code == 8 ) { previous_sequence[targetElement.id] = ''; return true; } // Backspace
// If this keystroke is a function key of any kind, do not filter it
if (e.charCode == 0 || e.which ==0 ) return true; // Function key (Firefox and Opera), e.charCode for Firefox and e.which for Opera
if (e.ctrlKey || e.altKey) // Ctrl or Alt held down
{
if (e.ctrlKey && (e.keyCode == 13 || e.which == 109)) // pressed Ctrl+M
{
enableTrasliteration(targetElement.id, !trasliteration_fields[targetElement.id]);
return false;
}
return true;
}
if (code < 32) return true; // ASCII control character
if(trasliteration_fields[targetElement.id])
{  
var c = String.fromCharCode(code);
var selectionRange = GetCaretPosition(targetElement);
var lastSevenChars = getLastSixChars(targetElement.value, selectionRange['start']);  
if(code ==62 && previous_sequence[targetElement.id ].substring(previous_sequence[targetElement.id ].length-1)=="<")
{
var oldString = "<>";
var newString = "";
temp_disable[targetElement.id] = !temp_disable[targetElement.id];
}
else {
if(!temp_disable[targetElement.id])
{
var transPair = trans(lastSevenChars+c, e);
var oldString = transPair[0];
var newString = transPair[1];
}
else
{
var oldString = c;
var newString = c;
}
}