How to get Clipboard data in Chrome Extension?

I'm having a hard time finding any recent info on how to add a listener for "Ctrl+C", fetching clipboard data, and then writing back to clipboard all in a Chrome Extension. All of the old code that i found was for the older versions that are now deprecated.

Basically you can manipulate clipboard using document.execCommand('paste|copy|cut').

• You'll need to specify "clipboardWrite" and/or "clipboardRead" permissions in manifest.

  "clipboardRead" Required if the extension or app uses document.execCommand('paste').

  "clipboardWrite" Indicates the extension or app uses document.execCommand('copy') or document.execCommand('cut'). This permission is required for hosted apps; it's recommended for extensions and packaged apps.

• Create <input> element (or <textarea>)

• Put focus to it
• Call document.execCommand('paste')
• Grab you string from <input> value attribute.

This worked for me to copy data to clipboard.

In order to read Clipboard text in a chrome extension, you have to:

• request "clipboardRead" permission in your manifest
• create a background script, since only the background script can access the clipboard
• create an element in your background page to accept the clipboard paste action. If you make this a textarea, you will get plain-text, if you make it a div with contentEditable=true, you will get Formatted HTML
• if you want to pass the clipboard data back to an in page script, you'll need to use the message-passing API

To see an example of this all working, see my BBCodePaste extension:

https://github.com/jeske/BBCodePaste

Here is one example of how to read the clipboard text in the background page:

bg = chrome.extension.getBackgroundPage();        // get the background page
bg.document.body.innerHTML= "";                   // clear the background page

// add a DIV, contentEditable=true, to accept the paste action
var helperdiv = bg.document.createElement("div");
document.body.appendChild(helperdiv);
helperdiv.contentEditable = true;

// focus the helper div's content
var range = document.createRange();
range.selectNode(helperdiv);
window.getSelection().removeAllRanges();
window.getSelection().addRange(range);
helperdiv.focus();    

// trigger the paste action
bg.document.execCommand("Paste");

// read the clipboard contents from the helperdiv
var clipboardContents = helperdiv.innerHTML;