how to bind key combination ctrl+x+return in jquery

Question

Is there any way to catch key combination ctrl+x+return in jquery(or javascript), such that if user presses this key combination, a function

Answer 1

Use a global boolean array var keys = [] to check whether a key is pressed. Then use the following function to add a global hotkey:

window.addGlobalHotkey = function(callback,keyValues){
    if(typeof keyValues === "number")
        keyValues = [keyValues];

    var fnc = function(cb,val){
        return function(e){
            keys[e.keyCode] = true;
            executeHotkeyTest(cb,val);
        };        
    }(callback,keyValues);
    window.addEventListener('keydown',fnc);
    return fnc;
};

As you can see it adds a new listener to the 'keydown' event. This listener will first set the corresponding value in keys true and then execute a test, whether the given keyValues are currently true. Note that you cannot remove keys[e.keyCode] = true and put it in another listener because this could result in a wrong callback order (first hotkey testing, then key mapping). The executeHotkeyTest itself is very easy too:

window.executeHotkeyTest = function(callback,keyValues){
    var allKeysValid = true;

    for(var i = 0; i < keyValues.length; ++i)
        allKeysValid = allKeysValid && keys[keyValues[i]];

    if(allKeysValid)
        callback();
};

At last you have to add another listener to keyup to clean the released keys from keys.

window.addEventListener('keyup',function(e){
    keys[e.keyCode] = false;
});

Now you can add a hotkey to ctrl+x+enter by using addGlobalHotkey(callback,[13,17,88]):

addGlobalHotkey(function(){
    document.body.appendChild(
        document.createElement('div').appendChild(
            document.createTextNode('Ctrl + x + Enter down')
    ).parentNode);
},[88,13,17]);

JSFiddle demo

Instead of adding a listener for every hotkey you can use a global [[callback1,values1],[callback2,values2],...] array.

Important note: in IE prior version 9 you have to use attachEvent instead of addEventListener. Since you're already using jQuery you could use .on(...) or .keydown instead.