Chrome extensions keyboard shortcut handler

gistfile1.js

/*
Right here's the thing - for keyPress events to be run, you'll have to make use of
 content scripts. Content scripts handle things at webpage & DOM level. You'll have 
to do changes to your manifest:
*/
------------------------
manifest.json:
------------------------
/* 
Note: don't replace manifest.json, add the relevant changes else 
toolbar icon won't work. 

*/

{
  "name": "blah",
  "version": "0.1",
  "description": "blah",
  
  "background_page": "bg.html", // change to your background page
  "permissions": ["http://*/*", "tabs"], //need permission to access all pages & tabs
   "content_scripts": [
   {
     "matches": ["http://*/*", "https://*/*"], // run for http & https pages
     "js": ["key_event.js"],  // key_event.js is injected to the page, this handles key press
     "run_at": "document_start" // run before everything else, else there will be conflicts at pages which accept keyboard inputs ( eg:google search)
   }
   ]
}

------------------------
key_event.js
------------------------

if (window == top) {
window.addEventListener('keyup', doKeyPress, false); //add the keyboard handler
}

trigger_key = 71; // g key
function doKeyPress(e){
	if (e.shiftKey && e.keyCode == trigger_key){ // if e.shiftKey is not provided then script will run at all instances of typing "G"
		//alert('Hi!')
	}
}

------------------------
/*
Now to make things complicated, content scripts are sandboxed and cannot do things
 like URL redirection. So, we'll have to use Chrome's message passing API.
*/
------------------------
bg.html
------------------------


//add this to handle message passing

chrome.extension.onRequest.addListener(function(request, sender) {
        chrome.tabs.update(sender.tab.id, {url: request.redirect});
    });

/*
consequently, you'll have to change things at key_event.js to pass the message
*/
--------------------------------
key_event.js
--------------------------------

if (window == top) {
window.addEventListener('keyup', doKeyPress, false); //add the keyboard handler
}

trigger_key = 71; // g key
function doKeyPress(e){
	if (e.shiftKey && e.keyCode == trigger_key){ // if e.shiftKey is not provided then script will run at all instances of typing "G"
		chrome.extension.sendRequest({redirect: newurl}); //build newurl as per viewtext URL generated earlier.
	}
}

----------------
/*
To summarize:
Add content script reference to your manifest. If webpage pattern matches 
"content_scripts": "matches" pattern, key_event.js will be injected to each page. 
key_event will check if shift+g is pressed and will send a message via sendRequest(). 
The background page will intercept sendRequest and send a redirect
 to the new URL (text only URL).
*/

That is great! But do you know how to handle keyboard events if a user set focus on an address bar or "find on the page" input fields?
I want to catch keyup event of the Alt key in my extension and it is working. But only if the page has a user focus, but if the user is focused on the address bar of the browser then it doesn't fire.

use this: https://developer.chrome.com/apps/commands (4 hotkeys max)

use this: https://developer.chrome.com/apps/commands (4 hotkeys max)

@avalanche1 thanks for the willingness to help but it is not what I described. There is no way to listen on Alt key events in extension if the user is not focused on a page.

You are wrong. Just checked - Alt+z works when focus is in address bar. Try harder ;)

@avalanche1, my question was about single key, specifically Alt key, and not about key combinations.

Thank you! this was the base for my First Chrome extension
https://github.com/Neves97/ChromeExtensionKeyboardInput.git