piskel/js/KeyManager.js

(function () {
    var ns = $.namespace("pskl");

    ns.KeyManager = function () {
        $(document.body).keydown($.proxy(this.onKeyUp_, this));
    };

    // Kind of object that make you want to stop front-end _engineering_:
    ns.KeyManager.prototype.CharCodeToKeyCodeMap = {

        90 : "z",
        89 : "y",
        88 : "x",
        67 : "c",
        86 : "v"
    };

    ns.KeyManager.prototype.KeyboardActions = {

        "ctrl" : {
            "z" : Events.UNDO,
            "y" : Events.REDO,
            "x" : Events.CUT,
            "c" : Events.COPY,
            "v" : Events.PASTE
        }
    };

    ns.KeyManager.prototype.onKeyUp_ = function(evt) {
        var isMac = false;
        if (navigator.appVersion.indexOf("Mac")!=-1) {
            // Welcome in mac world where vowels are consons and meta used instead of ctrl:
            isMac = true;
        }
        
        if (isMac ? evt.metaKey : evt.ctrlKey) {
            // Get key pressed:
            var letter = this.CharCodeToKeyCodeMap[evt.which];
            if(letter) {
                var eventToTrigger = this.KeyboardActions.ctrl[letter];
                if(eventToTrigger) {
                    $.publish(eventToTrigger);
                }
            }
        }
    };

})();