/* isiri2901.js - Standard Persian keyboard driver for JavaScript
*
* Copyright (C) 2000  Roozbeh Pournader
* Copyright (C) 2003, 2005  Behdad Esfahbod
* Copyright (C) 2005, 2006  Pooya Karimian
* Copyright (C) 2005  Behnam Esfahbod
* Copyright (C) 2005  Artyom Lukanin
*
* ChangeLog:
* Mar 05, 2005  Pooya Karimian, FireFox/Mozilla support added.
* Mar 20, 2005  Behdad Esfahbod, random fixes in Firefox support.
* Apr 14, 2005  Behnam Esfahbod, U+0654, U+0670, U+00F7 added.
* Apr 21, 2005  Behdad Esfahbod, Minimal Opera 8.0 support added.
*               Alt+Ctrl+anything now is known to switch language.
* Sep 06, 2005  Artyom Lukanin, FireFox 1.0.6 support added.
* Sep 09, 2005  Behdad Esfahbod, Added fallback support back in,
*               removed Opera code that doesn't was not worth it.
* Sep 09, 2005  Behdad Esfahbod, Make toggleDir() with no object
*               passed changing language, actually work.
* Sep 09, 2005  Added U+FDFC RIAL SIGN!
* Sep 09, 2005  Assigned U+0653 to shift+X.
* Dec 02, 2005  Pooya Karimian, Fixing vertical & horizontal scrolling
* Apr 13, 2006  Pooya Karimian, initKeyEvent is back in Firefox 1.5.0.2 (FF Bug#303713)
* Aug 13, 2006  Pooya Karimian, Fixing events bubbling recursively
*
* Licensed under GNU GPL.
*/

var isiri2901_lang = 1;        // 1: Persian, 0: English
var isiri2901_nativelang = 0;  // 1: Persian, 0: English

// Persian keyboard map based on ISIRI-2901

var isirikey = [
  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, 0x007E
];

// on Alt+Ctrl+anything, switch language
function PersianKeyDown(e) {
    if (window.event)
        e = window.event;
    if (e.ctrlKey && e.altKey) {
        if (isiri2901_lang == 0)
            setPersian();
        else
            setEnglish();
        try {
            e.preventDefault();
        } catch (err) {
        }
        return false;
    }
    return true;
}

var pk_test_ev;

function PersianKeyPress(e) {
    var key;
    var obj;


    if (window.event) {
        e = window.event;
        obj = e.srcElement;
        key = e.keyCode;
    } else {
        obj = e.target;
        key = e.charCode;
    }

    if (e.bubbles == false)
        return true;

    //  Change to English, if user is using an OS non-English keyboard
    if (key >= 0x00FF) {
        isiri2901_nativelang = 1;
        setPersian();
    } else
        if (isiri2901_nativelang == 1) {
        isiri2901_nativelang = 0;
        setEnglish();
    }


    // Avoid processing if control or higher than ASCII
    // Or ctrl or alt is pressed.
    if (key < 0x0020 || key >= 0x007F || e.ctrlKey || e.altKey || e.metaKey)
        return true;

    if (isiri2901_lang == 1) { //If Persian

        // rewrite key
        var newkey;
        if (key == 0x0020 && e.shiftKey) // Shift-space -> ZWNJ
            newkey = 0x200C;
        else
            newkey = isirikey[key - 0x0020];

        if (newkey == key)
            return true;


        try {
            // Gecko 
            var new_event = document.createEvent("KeyEvents");
            new_event.initKeyEvent("keypress", false, true, document.defaultView, false, false, false, false, 0, newkey);
            obj.dispatchEvent(new_event);
            e.preventDefault();
        } catch (err) {
            try {
                // Windows
                e.keyCode = newkey;
            } catch (err) {
                try {
                    // Gecko after banning fake key emission (FF 1.0.6 to FF 1.5.0.1)
                    // Try inserting at cursor position
                    pnhMozStringInsert(obj, String.fromCharCode(newkey));
                    e.preventDefault();
                } catch (err) {
                    // Everything else, simply add to the end of buffer
                    obj.value += String.fromCharCode(newkey);
                    e.preventDefault();
                } 
            } 
        }
    }
    return true;
}


function setPersian(obj, quiet) {
    isiri2901_lang = 1;
    if (obj) {
        obj.style.textAlign = "right";
        obj.style.direction = "rtl";
        obj.focus();
    }
    if (!quiet)
        window.defaultStatus = "Persian Keyboard (Press Ctrl+Alt+Space to change to English)";
}


function setEnglish(obj, quiet) {
    isiri2901_lang = 0;
    if (obj) {
        obj.style.textAlign = "left";
        obj.style.direction = "ltr";
        obj.focus();
    }
    if (!quiet)
        window.defaultStatus = "English Keyboard (Press Ctrl+Alt+Space to change to Persian)";
}


function toggleDir(obj, quiet) {
    var isrtl = 0;
    if (obj)
        isrtl = obj.style.direction != 'ltr';
    else
        isrtl = isiri2901_lang;
    if (isrtl)
        setEnglish(obj, quiet);
    else
        setPersian(obj, quiet);
}

// Inserts a string at cursor
function pnhMozStringInsert(elt, newtext) {
    var posStart = elt.selectionStart;
    var posEnd = elt.selectionEnd;
    var scrollTop = elt.scrollTop;
    var scrollLeft = elt.scrollLeft;

    elt.value = elt.value.slice(0, posStart) + newtext + elt.value.slice(posEnd);
    var newpos = posStart + newtext.length;
    elt.selectionStart = newpos;
    elt.selectionEnd = newpos;
    elt.scrollTop = scrollTop;
    elt.scrollLeft = scrollLeft;
    elt.focus();

}