jtk.js

/*
 * Javascript Thaana Keyboard 4.2.2
 *
 * Copyright (c) 2014 Jawish Hameed (jawish.org)
 * Licensed under the MIT license.
 */

var thaanaKeyboard = {

    // Default keyboard (used only when not explicitly declared using state)
    defaultKeyboard: '',

    // Default class name used for hooking at initialization
    className: 'thaanaKeyboardInput',

    // Setup Ascii Thaana -> Unicode translation matrix
    _transFrom: 'qwertyuiop[]\\asdfghjkl;\'zxcvbnm,./QWERTYUIOP{}|ASDFGHJKL:\"ZXCVBNM<>?()',
    _transToKbd: {	'phonetic': 'ްއެރތޔުިޮޕ][\\ަސދފގހޖކލ؛\'ޒ×ޗވބނމ،./ޤޢޭޜޓޠޫީޯ÷}{|ާށޑﷲޣޙޛޚޅ:\"ޡޘޝޥޞޏޟ><؟)(',
        'phonetic-hh': 'ޤަެރތޔުިޮޕ][\\އސދފގހޖކލ؛\'ޒޝްވބނމ،./ﷲާޭޜޓޠޫީޯޕ}{|ޢށޑޟޣޙޛޚޅ:\"ޡޘޗޥޞޏމ><؟)(',
        'typewriter': 'ޫޮާީޭގރމތހލ[]ިުްަެވއނކފﷲޒޑސޔޅދބށޓޯ×’“/:ޤޜޣޠޙ÷{}<>.،\"ޥޢޘޚޡ؛ޖޕޏޗޟޛޝ\\ޞ؟)('
    },


    /**
     * Apply input handling to elements with the special JTK class name
     */
    init: function () {
        this.setHandlerByClass(this.className, 'enable');
    },

    /**
     * Set key event handlers for a given element
     *
     * @param element	DOM Element to affect
     * @param action	String specifying action to take. Should be 'enable' or 'disable'.
     */
    setHandlerByElement: function (elem, action) {

        // Respond to action specified
        switch (action) {
            case 'enable':
                // Enable input handling
                elem.onkeypress = this.handleKey;

                break;

            case 'disable':
                // Disable input handling
                elem.onkeypress = null;

                break;
        }
    },

    /**
     * Set key event handlers for elements with the specified id
     *
     * @param id		String id of the element to affect
     * @param action	String specifying action to take. Should be 'enable' or 'disable'.
     */
    setHandlerById: function (id, action) {
        // Get the element object
        var elem = document.getElementById(id);

        this.setHandlerByElement(elem, action);
    },

    /**
     * Set key event handlers for elements of the specified class
     *
     * @param clsname	String class name of the elements to affect
     * @param action	String specifying action to take. Should be 'enable' or 'disable'.
     */
    setHandlerByClass: function (clsname, action) {
        // Setup regular expression for finding the target class
        var rePat = new RegExp('\\b' + clsname + '\\b');

        // Get all the elements on page
        var elemList = document.all || document.getElementsByTagName('*');

        // Loop through the elements
        for (n = 0; n < elemList.length; n++) {
            // Ensure the current element is of the target class
            if (rePat.test(elemList[n].className)) {
                // Set handler
                this.setHandlerByElement(elemList[n], action);
            }
        }
    },

    /**
     * Do character translation on key activity
     */
    handleKey: function (e) {
        // Get the event data
        if (!e) var e = window.event;

        // Get the pressed key
        if (e.which == null) {
            // IE:
            keycode = e.keyCode;
        }
        else if (e.which > 0) {
            // Non-IE printable chars:
            keycode = e.which;

            // Handle special keys misfire in Opera
            if (window.opera && [45, 46, 35, 36].indexOf(keycode) == 1) return true;
        }
        else {
            // Ignore special keys
            return true;
        }

        // Check for CTRL modifier key
        if (e.modifier) {
            var ctrl = e.modifiers & Event.CONTROL_MASK;
        }
        else if (typeof(e.ctrlKey) != 'undefined') {
            var ctrl = e.ctrlKey;
        }

        // Get translation details for the entered char
        try {
            var transIndex = thaanaKeyboard._transFrom.indexOf(String.fromCharCode(keycode));

            // If pressed key does not require translation, let default action proceed
            if (transIndex == -1 || ctrl) return true;


            // Set default state
            var state = thaanaKeyboard.defaultKeyboard;

            // Get state
            var elemState = document.getElementsByName(this.id + '_thaanaKeyboardState');
            if (elemState) {
                // State element has been defined:

                // Get the state specified by the element
                for (i = 0; i < elemState.length; i++) {
                    if (elemState[i].type == 'radio' || elemState[i].type == 'checkbox') {
                        // Handle radio/checkbox fields
                        if (elemState[i].checked == true) {
                            state = elemState[i].value;
                            break;
                        }
                    }
                    else if (elemState[i].type == 'select-one') {
                        // Handle select/combo list fields
                        state = elemState[i].options[elemState[i].selectedIndex].value;
                        break;
                    }
                    else if (elemState[i].type == 'hidden' || elemState[i].type == 'text') {
                        // Handle hidden and text fields
                        state = elemState[i].value;
                        break;
                    }

                }
            }

            // Look up the translated char
            var transChar = thaanaKeyboard._transToKbd[state].substr(transIndex, 1);
        }
        catch (err) {
            // Incorrect type or type not defined, return immediately
            return;
        }

        // Cancel default action for the key
        if (typeof e.preventDefault == 'function') {
            e.preventDefault();
        }
        else {
            e.returnValue = false;
        }

        // Store scroll position for textarea
        var sPos = this.scrollTop;

        // Insert text at cursor position
        if (this.selectionStart) {
            // For Firefox/Safari:
            var selOld = this.selectionStart + 1;
            this.value = this.value.substring(0, this.selectionStart)
                + transChar
                + this.value.substring(this.selectionEnd, this.value.length);

            this.setSelectionRange(selOld, selOld);
            this.focus();
        }
        else if (document.selection) {
            // For IE/Opera:
            sel = document.selection.createRange();
            sel.text = transChar;
            this.focus();
        }
        else {
            // If all fails, just append
            this.value += transChar;
        }

        // Restore scroll position for textarea
        this.scrollTop = sPos;
    }

};

// Start the Thaana Keyboard soon as the page is loaded
var old = (window.onload) ? window.onload : function () {};
window.onload = function(){old(); thaanaKeyboard.init();};