// kblayout.js
// Copyright (C) 2009 M. Mahdi Hasheminezhad (hasheminezhad at gmail dot com)
// Cross-Browser keyboard layout switcher with support of new layouts
// This source is licensed under Common Public License Version 1.0 (CPL) 
// History:
// 2009-08-30 First Public Release M. Mahdi Hasheminezhad (http://hasheminezhad.com)

var keyboardLayout = {};
var langCycle = [''];

(function() {
    var k = null;
    var titleTimeout = null;

    function showLang(langIndex) {
        var langTitle = 'Language: ';
        for(var i=0;i<langCycle.length;i++) {
            var lang = getLangFromCycle(i) || 'default';
            langTitle += (i == langIndex ? '['+lang+']' : lang) + ' ';
        }

        if(titleTimeout) clearTimeout(titleTimeout);
        document.oldTitle = document.oldTitle || document.title;
        document.title = langTitle;
        titleTimeout = setTimeout(function() {
            document.title = document.oldTitle;
            document.oldTitle = undefined;
            titleTimeout = null;
        }, 1000);
    }

    function getLangFromCycle(i) {
        return langCycle[i].lang ? langCycle[i].lang : langCycle[i];
    }

    function getDirectionFromCycle(i) {
        return langCycle[i].direction ? langCycle[i].direction : '';
    }

    function getNextLangIndex(targetLang) {
        var nextIndex = langCycle.length ? 0 : -1;
        for(var i=0; i < langCycle.length; i++){
            if(getLangFromCycle(i) == targetLang){
                nextIndex = i < langCycle.length-1 ? i + 1 : 0;
            }
        }
        return nextIndex;
    }

    function addEvent(elem, type, handle){
	    if (elem.addEventListener)
		    elem.addEventListener(type, handle, false);
	    else if (elem.attachEvent)
		    elem.attachEvent("on" + type, handle);
		else
		    elem["on" + type] = handle;
    }

    function isTextField(elem){
        return (elem.tagName == 'TEXTAREA') ||
            (elem.tagName == 'INPUT' && elem.type && elem.type.toUpperCase() == 'TEXT');
    }
    
    addEvent(document, "keydown", function(e){if(e) k = e.which;});
    addEvent(document, "keypress", function(e){
        var target = e.target || e.srcElement;
        if(!isTextField(target)) return;
        var key = e.which || e.charCode || e.keyCode;
        
        //read layout language from lang attribute
        var lang = (target.getAttribute('lang') || '').match(/^[a-zA-Z]{2}/) || '';
        if(!lang){
            if(!langCycle.length) return true;
            lang = getLangFromCycle(0);
        }

        // Ctrl+Space changes language (just if there's any cycle available)
        if (e.ctrlKey && key == 0x0020 && langCycle && langCycle.length > 1) {
            var nextLangIndex = getNextLangIndex(lang);
            if(nextLangIndex >= 0) {
                showLang(nextLangIndex);
                target.setAttribute('lang', getLangFromCycle(nextLangIndex));
                target.style.direction = getDirectionFromCycle(nextLangIndex);
            }
            if(e.preventDefault) e.preventDefault();
            e.returnValue = false;
            return false;
        }

        var layout = keyboardLayout[lang];
        if ((!layout) ||
            (e.ctrlKey || e.altKey || e.metaKey) ||
            (k != 0x0020 && k < 0x0030) ||  //fix for opera
            (key < 0x0020 || key > 0x007F))
            return true;

        var value =
            (key == 0x0020 && e.shiftKey && layout[0x005f]) ||  //Shift+Space may be defined in layout[0x5f]
            (layout[key - 0x0020]);

        value = typeof value=='string'?
            value:
            String.fromCharCode(value);

        var ds = document.selection,
            ss = target.selectionStart;

        if (typeof ss == 'number') { //standard browsers: http://www.w3.org/TR/html5/editing.html#dom-textarea-input-selectionstart
	        var sl = target.scrollLeft, st = target.scrollTop;  //fix for firefox
	        target.value = target.value.substring(0, ss) + value + target.value.substring(target.selectionEnd, target.value.length);
	        var sr = ss + value.length;
	        target.setSelectionRange(sr, sr);
            target.scrollLeft = sl;
            target.scrollTop = st;
        } else if (ds) { //IE: http://msdn.microsoft.com/en-us/library/ms535869(VS.85).aspx
	        var r = ds.createRange();
	        r.text = value;
            r.setEndPoint('StartToEnd', r);
            r.select();
        } else { //unknown browsers
	        target.value += value;
        }

        if(e.preventDefault) e.preventDefault();
        e.returnValue = false;
        return false;
    });
})();

// kblayout.fa.js
// Standard farsi layout for kblayout.js
// M. Mahdi Hasheminezhad (hasheminezhad at gmail dot com)
keyboardLayout['fa'] = [
  0x0020, 0x0021, 0x061b, 0x066b, 0xfdfc, 0x066a, 0x060c, 0x06af, 0x0029, 0x0028, 0x002a, 0x002b, 0x0648, 0x002d, 0x002e, 0x002f,
  0x06f0, 0x06f1, 0x06f2, 0x06f3, 0x06f4, 0x06f5, 0x06f6, 0x06f7, 0x06f8, 0x06f9, 0x003a, 0x06a9, 0x003e, 0x003d, 0x003c, 0x061f,
  0x066c, 0x0624, 0x200c, 0x0698, 0x064a, 0x064d, 0x0625, 0x0623, 0x0622, 0x0651, 0x0629, 0x00bb, 0x00ab, 0x0621, 0x0654, 0x005d,
  0x005b, 0x0652, 0x064b, 0x0626, 0x064f, 0x064e, 0x0670, 0x064c, 0x0653, 0x0650, 0x0643, 0x062c, 0x005c, 0x0686, 0x00d7, 0x0640,
  0x200d, 0x0634, 0x0630, 0x0632, 0x06cc, 0x062b, 0x0628, 0x0644, 0x0627, 0x0647, 0x062a, 0x0646, 0x0645, 0x067e, 0x062f, 0x062e,
  0x062d, 0x0636, 0x0642, 0x0633, 0x0641, 0x0639, 0x0631, 0x0635, 0x0637, 0x063a, 0x0638, 0x007d, 0x007c, 0x007b, 0x00f7, 0x200c
];
langCycle.push({lang: 'fa', direction: 'rtl'});