Chrome Extension: Insert Fixed Div As Ui

I want to insert a div into a fixed position using a chrome extension. It will overlay the page that you are currently viewing. My concern is that I want this to work on any page w

Solution 1:

Manipulating content from background.js is a very bad idea. Why don't you use content script?

manifest.json

{
    "name":"poop",
    "version":"0.1",
    "manifest_version":2,
    "description":"shitty app I'm making",
    "background":{
        "scripts":[
            "scripts/modernizr.min.js", 
            "scripts/background.js"
            ],
        "persistent": false
    },
    "content_scripts": [
      {
        "matches": ["https://*/*", "http://*/*"],
        "js": ["content.js"],
        "run_at": "document_end"
      }
    ],
    "permissions":[
        "contextMenus", 
        "tabs",
        "http://*/*",
        "https://*/*"
        ],
    "icons":{
        "16":"images/icon_16.png",
        "128":"images/icon_128.png"
    }
}

content.js

document.documentElement.style.height = '100%';
document.body.style.height = '100%';
document.documentElement.style.width = '100%';
document.body.style.width = '100%';

var div = document.createElement( 'div' );
var btnForm = document.createElement( 'form' );
var btn = document.createElement( 'input' );

//append all elements
document.body.appendChild( div );
div.appendChild( btnForm );
btnForm.appendChild( btn );
//set attributes for div
div.id = 'myDivId';
div.style.position = 'fixed';
div.style.top = '50%';
div.style.left = '50%';
div.style.width = '100%';   
div.style.height = '100%';
div.style.backgroundColor = 'red';

//set attributes for btnForm
btnForm.action = '';

//set attributes for btn
//"btn.removeAttribute( 'style' );
btn.type = 'button';
btn.value = 'hello';
btn.style.position = 'absolute';
btn.style.top = '50%';
btn.style.left = '50%';