How to capture Mouse and Keyboard data across all websites for Chrome

Question

Just as the title implies. How would I go about capturing general event data across websites? This is supposed to be a strictly client-side application. Would a chrome extension work? If so, how would I go about it? Does one already exist, or at least an alternative method?

Answer 1

In chrome extension, Content scripts are scripts that run in the context of web pages. You could listent to specific events (such as MouseEvent and KeyboardEvent ) just like normal scripts.

manifest.json

{
  "manifest_version": 2,
  "name": "Test extension",
  "version": "1.0",
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "all_frames": true
    }
  ]
} 

content.js

document.addEventListener('mousedown', function (e) {
    console.log('mouse down');
}, false);

document.addEventListener('keydown', function (e) {
    console.log('key down');
}, false);