Chrome Extension - How to capture Scroll Position on open tabs

Question

I currently capture scroll location on a tab by running it in a content script (see below) and injecting JQuery.

Question How do I apply scroll capture to all tabs open not just the current tab I'm on? My try below works for just current tab.

Unsure how to iterate a for loop across all tabs since don't have access to chrome.tabs API in content script. Am I approaching this wrong by constantly tracking scroll capture and should use a background.js to call a content_script function only on a certain event?

Thanks!

manifest.json

{
"manifest_version": 2,
"name": "ScrollPosition",
"version": "1.0",
"background": {
"page": "background.html"
},
"content_scripts": [
{ "matches": ["http://*/*", "https://*/*"],
"js": ["jquery-1.11.1.min.js","content_script.js"]}
],
"browser_action": {
    "default_icon": {
        "19": "images/icon19.png",
        "38": "images/icon38.png"
    },
    "default_popup": "popup.html"
},
"permissions": [
    "tabs",
    "windows",
    "<all_urls>",
    "chrome://favicon/",
]
}

content_script.js

var scrollPosition = 0;

function scrollPos() {
  $(document).scroll(function(){
    scrollPosition = $(this).scrollTop();  
    console.log('your scroll position is: '+scrollPosition);
  });
};

window.addEventListener("load", scrollPos);

Answer 1

You can use the background script to iterate over all tabs and inject custom scripts. You can iterate over all tabs in the background page using chrome.tabs.query. You can inject a script into a tab using chrome.tabs.executeScript. Now, you'll just need to send a message to the background script from your content script and you should be good to go.