javascript capture browser shortcuts (ctrl+t/n/w)

72
votes

Is it possible to capture these shortcuts?

  • Ctrl+N
  • Ctrl+T
  • Ctrl+W

I tried this but it doesn't work:

$(window).keydown(function(event) {
  console.log(event.keyCode);
  event.preventDefault();
});

When I press T it shows 84 in the console, but if I press Ctrl+T it shows nothing, and opens a new tab.

I would like to capture these shortcuts and prevent any browser action.

5
jqueryeventsbrowserkeyboard-shortcuts
Forget about CTRL + key commands. That's above JavaScript... – Šime Vidas
I can override Ctrl+S, Ctrl+R andso. I think only 3-4 shortcut cannot be overriden. – Gergely Fehérvári
If you've ever entered a question or answer on StackOverflow, you would surely have found that it is possible. Have you ever typed Ctrl+L? You'd expect the cursor to jump to the address bar, but StackOverflow captures it, expecting a URL for a link in your question or answer. Ctrl shortcuts are captured on DropBox and Google Docs as well. In the spirit of @Juhana's comment, it's unfortunate. (This is true under Linux, anyhow. I don't know about Windows, nor how it works with Apple's proprietary modifier keys.) – Michael Scheper

5 Answers

112
votes

Capturing Ctrl keyboard events in Javascript

Sample code:

$(window).keydown(function(event) {
  if(event.ctrlKey && event.keyCode == 84) { 
    console.log("Hey! Ctrl+T event captured!");
    event.preventDefault(); 
  }
  if(event.ctrlKey && event.keyCode == 83) { 
    console.log("Hey! Ctrl+S event captured!");
    event.preventDefault(); 
  }
});

Firefox

(6.0.1 tested)

In Firefox both event listener works. If you press CtrlT or CtrlS keycombinations, you will get both message on the console, and the browser wont open a tab, nor ask for save.

It is intresting that if you use alert instead of console.log the event.preventDefault() not works, and opens a new tab or asks for save. Maybe this bug needs to get fixed.

Chrome3

In Chrome 3 it works like in Firefox.

Chrome4

(tested)

In Chrome4, certain control key combinations have been reserved for browser usage only and can no longer be intercepted by the client side JavaScript in the web page.
These restrictions did not exist in Chrome3 and are inconsistent with both Firefox3/3.5 and IE7/8 (on Windows).

In Chrome 4 it works similary to Firefox, except some keyboard combination:

  • CtrlN

  • CtrlShiftN

  • CtrlT

  • CtrlShiftT

  • CtrlW

  • CtrlShiftW

These combinations cannot get captured by Javascript, but embed plugins can capture these. For example if you focus in a Youtube video and press CtrlT, the browser won't open a new tab.

IE7/8

It works like in Firefox or Chrome3.

IE9

(tested)

IE9 is a black sheep again, because it dosen't allow javascript to capture any Ctrl? keyboard event. I tested with many keyboard combination (R,T,P,S,N,T) and neither worked. Also embed applications can't capture the event. Tested with Youtube videos.

Thanks to @Lime for the great link.

11
votes

As of March, 20th, 2012, there has been a Chrome fix that allows web applications to handle Control+NWT in Chrome in js keydown event (so it works in pure javascript, or any library like jQuery).

This fix allows javascript to handle this key combinations if Chrome is opened in Application mode, which can be done in this way:

The fix is documented here:

8
votes

To expand on the other answers:

The code to block certain combinations in Chrome/Chromium is defined here, im summary, F11 to exit fullscreen mode and everything manipulating and navigating tabs or windows is blocked:

[Shift]Ctrl(Q|N|W|T|Tab ↹)

2
votes

Instead of trapping the Ctrl+W hotkey, detect when the window is closed might be a valid option:

"The beforeunload event is fired when the window, the document and its resources are about to be unloaded.

When a non-empty string is assigned to the returnValue Event property, a dialog box appears, asking the users for confirmation to leave the page (see example below). When no value is provided, the event is processed silently."

1
votes

The answer is really simple: This is not possible directly without some tricks in javascript.

It depends on the browser. Mostly all browser catch this shortcuts and use it for their own events. (e.g open new tabs) The shortcut never reach the javascript engine.

What is easy possible however, to catch the shortcuts with flash. But this is wide away from a user friendly website.

Update:

Here a short example. Mostly all browser will show the alert when Ctrl+y is pressed. (y = 89)

document.onkeydown = keyDownEvent;
document.onkeyup = keyUpEvent;

var isCtrl = false;

function keyDownEvent() {
    var keyid = event.keyCode;

    if(keyid == 17) {
        isCtrl = true;
    }
}

function keyUpEvent() {
    var keyid = event.keyCode;

    if(keyid == 17) {
        isCtrl = false;
    }

    if(keyid == 89 && isCtrl == true) {
        alert('CTRL-Y pressed');   
    }
}

If you replace the 84 by 89, which represents a t, nothing will happen. You can try it on jsfiddle.net.