keyboard.js

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//      Keyboard Handler         //
 
define( [
                'jquery/jquery'
        ],
        function()
        {
 
                function keyboard(obj,_defaultHandler)
                {
                        this._commands = [];
 
                        obj.bind( "keydown keyup", this.keyHandler.bind(this) );
 
                        this._defaultHandler = _defaultHandler;
                }
 
                //http://www.cambiaresearch.com/c4/702b8cd1-e5b0-42e6-83ac-25f0306e3e25/javascript-char-codes-key-codes.aspx
                keyboard.codes = {      "CTRL":         17,             //null,
                                        "ALT":          18,             //null
                                        "META":         91,             //null,
                                        "SHIFT":        16,             //null,
                                        "LEFT":         37,
                                        "UP":           38,
                                        "RIGHT":        39,
                                        "DOWN":         40,
                                        "DEL":          46,
                                        "DELETE":       46,
                                        "BACKSPACE":    8,
                                        "SPACE":        32,
                                        "ENTER":        13,
                                        "ESCAPE":       27,
                                        "F1":           112,
                                        "F2":           113,
                                        "F3":           114,
                                        "F4":           115,
                                        "F5":           116,
                                        "F6":           117,
                                        "F7":           118,
                                        "F8":           119,
                                        "F9":           120,
                                        "F10":          121,
                                        "F11":          122,
                                        "F12":          123,
                                        "-":            189,
                                        "=":            187,
                                        "[":            219,
                                        "]":            221,
                                        ".":            190,
                                };
 
                keyboard.ignore = ["TEXTAREA","INPUT","SELECT"];
 
                keyboard.init = function()
                {
                        //console.log( "KEYBOARD INIT!" );
 
                        //var _keyboard = new keyboard($(document),keyboard,function(e) { keyboard.preventDefault(e); return false; } );
                        var _keyboard = new keyboard($(document));
 
                        _keyboard.registerCommand("Meta-a",             false );                //kill apple-A (select all)
                        //_keyboard.registerCommand("DEL, BACKSPACE",   false );                //kill delete as back button
                        _keyboard.registerCommand("DEL,BACKSPACE",false,false,false,1);         //prevent delete/backspace from causing the back button to trigger
                        _keyboard.registerCommand("Meta-s,Ctrl-s,Alt-s",false,false,false,1);   //prevent accidental saves
 
                        return _keyboard;
                }
 
                keyboard.preventDefault = function(e)
                {
                        //console.log("PREVENT DEFAULT");
                        e.preventDefault();
                        e.stopPropagation();
                        return true;                    //return true to keyHandler, which will in turn return false...
                }
 
                keyboard.prototype = {
 
                        registerCommand:        function(c,f,l,r,p)                                                     //Command, Functor, aLways, Releaseonly, Priority(1=first)
                                                {
                                                        var cs = c.split(",");
                                                        p = Math.max( (p || this._commands.length)-1, 0 );
 
                                                        for(var i=0;i<cs.length;i++)
                                                        {
                                                                var cc = jQuery.trim(cs[i]).toLowerCase();
                                                                this._commands.splice(p, 0, new keyboardCommand(cc,f,l,r) );
                                                        }
                                                },
 
                        unregisterCommand:      function(c,r)
                                                {
                                                        var cs = c.split(",");
                                                        var all = true;
 
                                                        for (var j=0;j<cs.length;j++)
                                                        {
                                                                c = jQuery.trim(cs[j]).toLowerCase();
 
                                                                var found=false;
                                                                for (var i=0;i<this._commands.length;i++)
                                                                {
                                                                        var m = this._commands[i];
                                                                        if ((m._command === c) && (m._releaseOnly === r))
                                                                        {
                                                                                var cc = this._commands.splice(i,1);
                                                                                found = true;
                                                                        }
                                                                }
 
                                                                all = all && found;
                                                        }
 
                                                        return all;
                                                },
 
                        keyHandler:             function(e)
                                                {
                                                        //console.log("handler!");
                                                        //console.log(e);
 
                                                        //if (keyboard.ignore.indexOf( e.target.nodeName.toUpperCase() ) != -1)
                                                        //      return false;
 
                                                        var x = false;
 
                                                        for (var i=0; i<this._commands.length; i++)
                                                        {
                                                                if (    (e.type === "keydown" && !this._commands[i]._releaseOnly) ||
                                                                        (e.type === "keyup" && this._commands[i]._releaseOnly)  )
                                                                {
                                                                        //console.log(e.type);
                                                                        //console.log(this._commands[i]._always);
                                                                        if (!this._commands[i]._always && keyboard.ignore.indexOf( e.target.nodeName.toUpperCase() ) != -1)
                                                                                continue;
 
                                                                        x |= this._commands[i].exec(e);
                                                                }
 
                                                                if (x)                                                  //first true kills the loop
                                                                {
                                                                        keyboard.preventDefault(e);
                                                                        //console.log("found key for "+e.type);
                                                                        return false;
                                                                }
                                                        }
 
                                                        //console.log("not found... default for "+e.type);
                                                        //console.trace();
 
                                                        if (this._defaultHandler)                                       //if a default handler is present, call it...
                                                                return this._defaultHandler(e)                          //      return its value
                                                },
 
                        listen:                 function(jq,_defaultHandler)
                                                {
                                                        return new keyboard(jq,_defaultHandler);
                                                },
 
                        destroy:                function()
                                                {
                                                        this._commands = [];
                                                },
                }
 
 
                //      Key Command Handler      //
 
                function keyboardCommand(command, functor, always, releaseOnly)
                {
                        this._function = functor || keyboard.preventDefault;
 
                        this._releaseOnly = releaseOnly;
                        this._always = always;
                        this._command = command;        //used to match for un-register
 
                        this._meta = false;
                        this._shift = false;
                        this._alt = false;
                        this._ctrl = false;
 
                        this._keyChar = null;
 
                        this.parse(jQuery.trim(command));
                }
 
                keyboardCommand.prototype = {
 
                        exec:                   function(e)
                                                {
                                                        var ubers = (
                                                                        this._meta      == e.metaKey    &&
                                                                        this._shift     == e.shiftKey   &&
                                                                        this._alt       == e.altKey     &&
                                                                        this._ctrl      == e.ctrlKey
                                                                );
 
                                                        //console.log("code: "+e.keyCode);
                                                        //console.log(ubers+" :: "+this._keyChar+" :: "+String.fromCharCode(e.keyCode));
                                                        //console.log(e);
 
                                                        if (ubers || this._releaseOnly)                                         //FIXME: release only won't have any ubers if it's only an uber.  Really the or clause shouldn't be here
                                                        {
                                                                if (this._keyChar)
                                                                {
                                                                        if (String.fromCharCode(e.keyCode) === this._keyChar || e.keyCode === this._keyChar)
                                                                        {
                                                                                if (this._function)
                                                                                {       this._function(e);
                                                                                        return true;
                                                                                }
                                                                        }
                                                                }
                                                                else
                                                                {
                                                                        if (this._function)
                                                                        {       this._function(e);
                                                                                return true;
                                                                        }
                                                                }
                                                        }
 
                                                        return false;
                                                },
 
                        parse:                  //expects something like ctrl+a or ctrl+shift+alt+x
                                                function(c)
                                                {
                                                        c = c.toLowerCase();
                                                        c = c.replace(" ","");
 
                                                        this._ctrl = (c.indexOf("ctrl")>-1) ? true : false;
                                                        this._alt = (c.indexOf("alt")>-1) ? true : false;
                                                        this._meta = ((c.indexOf("meta")>-1) || (c.indexOf("apple")>-1)) ? true : false;
                                                        this._shift = (c.indexOf("shift")>-1) ? true : false;
 
                                                        if (c==="-" || c==="+")
                                                                this._keyChar = c;
                                                        else
                                                                this._keyChar = c.split(/[+-]/).pop().toUpperCase();
 
                                                        if (this._keyChar in keyboard.codes)
                                                                this._keyChar = keyboard.codes[this._keyChar];
 
                                                        //console.log(this);
                                                        //console.trace();
                                                },
                }
 
                return keyboard.init();
        }
);