Question

I have a web app I’m developing and I’m trying to have CTRL+S and COMMAND+S be the shortcut keys to save. I’ve looked at http://www.openjs.com/scripts/events/keyboard_shortcuts/ and it doesn’t properly capture the “meta” key.

Any advice?

Answer 1

Latest Edit: Please, before downvoting this response take in mind that this is a very old response (2011) and has not been updated. Obviously there are better responses now (like the one by lapin) but that doesn’t mean that mine is invalid.

You can use jquery hotkeys.

Edit: There’s a newer version on github and you can use the ‘meta’ modifier to grab command+:

 $(document).bind('keydown', 'meta+s', myaction.save);

Edit2: You can also use the Mousetrap library/vendor, which is jQuery-free.

Download the latest version and modify it following the changes in this attachment: http://code.google.com/p/js-hotkeys/issues/detail?id=26

You only need to add three lines:

At line 188 aprox. (under ctrl = event.ctrlKey,) add this:

cmd = event.metaKey && !ctrl,

Then, add a negation to the if at line 203 aprox. ( if(!shift && !ctrl && !alt){ ):

if(!shift && !ctrl && !alt && !cmd){

Finally, under if(shift) modif += 'shift+'; add this:

if(cmd) modif += 'command+';

Now when you create a binding to command+whatever it will grab it:

$(document).bind('keydown', 'command+s', myaction.save);

Here you can grab the latest current version (0.7.9) modified:

/*
(c) Copyrights 2007 - 2008

Original idea by by Binny V A, http://www.openjs.com/scripts/events/keyboard_shortcuts/

jQuery Plugin by Tzury Bar Yochay 
[e-mail]
http://evalinux.wordpress.com
http://facebook.com/profile.php?id=513676303

Project's sites: 
http://code.google.com/p/js-hotkeys/
http://github.com/tzuryby/hotkeys/tree/master

License: same as jQuery license. 

USAGE:
    // simple usage
    $(document).bind('keydown', 'Ctrl+c', function(){ alert('copy anyone?');});

    // special options such as disableInIput
    $(document).bind('keydown', {combi:'Ctrl+x', disableInInput: true} , function() {});

Note:
    This plugin wraps the following jQuery methods: $.fn.find, $.fn.bind and $.fn.unbind
*/

(function (jQuery){
    // keep reference to the original $.fn.bind, $.fn.unbind and $.fn.find
    jQuery.fn.__bind__ = jQuery.fn.bind;
    jQuery.fn.__unbind__ = jQuery.fn.unbind;
    jQuery.fn.__find__ = jQuery.fn.find;

    var hotkeys = {
        version: '0.7.9',
        override: /keypress|keydown|keyup/g,
        triggersMap: {},

        specialKeys: { 27: 'esc', 9: 'tab', 32:'space', 13: 'return', 8:'backspace', 145: 'scroll', 
            20: 'capslock', 144: 'numlock', 19:'pause', 45:'insert', 36:'home', 46:'del',
            35:'end', 33: 'pageup', 34:'pagedown', 37:'left', 38:'up', 39:'right',40:'down', 
            109: '-', 
            112:'f1',113:'f2', 114:'f3', 115:'f4', 116:'f5', 117:'f6', 118:'f7', 119:'f8', 
            120:'f9', 121:'f10', 122:'f11', 123:'f12', 191: '/'},

        shiftNums: { "`":"~", "1":"!", "2":"@", "3":"#", "4":"$", "5":"%", "6":"^", "7":"&", 
            "8":"*", "9":"(", "0":")", "-":"_", "=":"+", ";":":", "'":"\"", ",":"<", 
            ".":">",  "/":"?",  "\\":"|" },

        newTrigger: function (type, combi, callback) { 
            // i.e. {'keyup': {'ctrl': {cb: callback, disableInInput: false}}}
            var result = {};
            result[type] = {};
            result[type][combi] = {cb: callback, disableInInput: false};
            return result;
        }
    };
    // add firefox num pad char codes
    //if (jQuery.browser.mozilla){
    // add num pad char codes
    hotkeys.specialKeys = jQuery.extend(hotkeys.specialKeys, { 96: '0', 97:'1', 98: '2', 99: 
        '3', 100: '4', 101: '5', 102: '6', 103: '7', 104: '8', 105: '9', 106: '*', 
        107: '+', 109: '-', 110: '.', 111 : '/'
        });
    //}

    // a wrapper around of $.fn.find 
    // see more at: http://groups.google.com/group/jquery-en/browse_thread/thread/18f9825e8d22f18d
    jQuery.fn.find = function( selector ) {
        this.query = selector;
        return jQuery.fn.__find__.apply(this, arguments);
    };

    jQuery.fn.unbind = function (type, combi, fn){
        if (jQuery.isFunction(combi)){
            fn = combi;
            combi = null;
        }
        if (combi && typeof combi === 'string'){
            var selectorId = ((this.prevObject && this.prevObject.query) || (this[0].id && this[0].id) || this[0]).toString();
            var hkTypes = type.split(' ');
            for (var x=0; x<hkTypes.length; x++){
                delete hotkeys.triggersMap[selectorId][hkTypes[x]][combi];
            }
        }
        // call jQuery original unbind
        return  this.__unbind__(type, fn);
    };

    jQuery.fn.bind = function(type, data, fn){
        // grab keyup,keydown,keypress
        var handle = type.match(hotkeys.override);

        if (jQuery.isFunction(data) || !handle){
            // call jQuery.bind only
            return this.__bind__(type, data, fn);
        }
        else{
            // split the job
            var result = null,            
            // pass the rest to the original $.fn.bind
            pass2jq = jQuery.trim(type.replace(hotkeys.override, ''));

            // see if there are other types, pass them to the original $.fn.bind
            if (pass2jq){
                result = this.__bind__(pass2jq, data, fn);
            }            

            if (typeof data === "string"){
                data = {'combi': data};
            }
            if(data.combi){
                for (var x=0; x < handle.length; x++){
                    var eventType = handle[x];
                    var combi = data.combi.toLowerCase(),
                        trigger = hotkeys.newTrigger(eventType, combi, fn),
                        selectorId = ((this.prevObject && this.prevObject.query) || (this[0].id && this[0].id) || this[0]).toString();

                    //trigger[eventType][combi].propagate = data.propagate;
                    trigger[eventType][combi].disableInInput = data.disableInInput;

                    // first time selector is bounded
                    if (!hotkeys.triggersMap[selectorId]) {
                        hotkeys.triggersMap[selectorId] = trigger;
                    }
                    // first time selector is bounded with this type
                    else if (!hotkeys.triggersMap[selectorId][eventType]) {
                        hotkeys.triggersMap[selectorId][eventType] = trigger[eventType];
                    }
                    // make trigger point as array so more than one handler can be bound
                    var mapPoint = hotkeys.triggersMap[selectorId][eventType][combi];
                    if (!mapPoint){
                        hotkeys.triggersMap[selectorId][eventType][combi] = [trigger[eventType][combi]];
                    }
                    else if (mapPoint.constructor !== Array){
                        hotkeys.triggersMap[selectorId][eventType][combi] = [mapPoint];
                    }
                    else {
                        hotkeys.triggersMap[selectorId][eventType][combi][mapPoint.length] = trigger[eventType][combi];
                    }

                    // add attribute and call $.event.add per matched element
                    this.each(function(){
                        // jQuery wrapper for the current element
                        var jqElem = jQuery(this);

                        // element already associated with another collection
                        if (jqElem.attr('hkId') && jqElem.attr('hkId') !== selectorId){
                            selectorId = jqElem.attr('hkId') + ";" + selectorId;
                        }
                        jqElem.attr('hkId', selectorId);
                    });
                    result = this.__bind__(handle.join(' '), data, hotkeys.handler)
                }
            }
            return result;
        }
    };
    // work-around for opera and safari where (sometimes) the target is the element which was last 
    // clicked with the mouse and not the document event it would make sense to get the document
    hotkeys.findElement = function (elem){
        if (!jQuery(elem).attr('hkId')){
            if (jQuery.browser.opera || jQuery.browser.safari){
                while (!jQuery(elem).attr('hkId') && elem.parentNode){
                    elem = elem.parentNode;
                }
            }
        }
        return elem;
    };
    // the event handler
    hotkeys.handler = function(event) {
        var target = hotkeys.findElement(event.currentTarget), 
            jTarget = jQuery(target),
            ids = jTarget.attr('hkId');

        if(ids){
            ids = ids.split(';');
            var code = event.which,
                type = event.type,
                special = hotkeys.specialKeys[code],
                // prevent f5 overlapping with 't' (or f4 with 's', etc.)
                character = !special && String.fromCharCode(code).toLowerCase(),
                shift = event.shiftKey,
                ctrl = event.ctrlKey,            
                // patch for jquery 1.2.5 && 1.2.6 see more at:  
                // http://groups.google.com/group/jquery-en/browse_thread/thread/83e10b3bb1f1c32b
                cmd = event.metaKey && !ctrl,
                alt = event.altKey || event.originalEvent.altKey,
                mapPoint = null;

            for (var x=0; x < ids.length; x++){
                if (hotkeys.triggersMap[ids[x]][type]){
                    mapPoint = hotkeys.triggersMap[ids[x]][type];
                    break;
                }
            }

            //find by: id.type.combi.options            
            if (mapPoint){ 
                var trigger;
                // event type is associated with the hkId
                if(!shift && !ctrl && !alt && !cmd) { // No Modifiers
                    trigger = mapPoint[special] ||  (character && mapPoint[character]);
                }
                else{
                    // check combinations (alt|ctrl|shift+anything)
                    var modif = '';
                    if(alt) modif +='alt+';
                    if(ctrl) modif+= 'ctrl+';
                    if(shift) modif += 'shift+';
                    if(cmd) modif += 'command+';
                    // modifiers + special keys or modifiers + character or modifiers + shift character or just shift character
                    trigger = mapPoint[modif+special];
                    if (!trigger){
                        if (character){
                            trigger = mapPoint[modif+character] 
                                || mapPoint[modif+hotkeys.shiftNums[character]]
                                // '$' can be triggered as 'Shift+4' or 'Shift+$' or just '$'
                                || (modif === 'shift+' && mapPoint[hotkeys.shiftNums[character]]);
                        }
                    }
                }
                if (trigger){
                    var result = false;
                    for (var x=0; x < trigger.length; x++){
                        if(trigger[x].disableInInput){
                            // double check event.currentTarget and event.target
                            var elem = jQuery(event.target);
                            if (jTarget.is("input") || jTarget.is("textarea") || jTarget.is("select") 
                                || elem.is("input") || elem.is("textarea") || elem.is("select")) {
                                return true;
                            }
                        }                       
                        // call the registered callback function
                        result = result || trigger[x].cb.apply(this, [event]);
                    }
                    return result;
                }
            }
        }
    };
    // place it under window so it can be extended and overridden by others
    window.hotkeys = hotkeys;
    return jQuery;
})(jQuery);