The "selectedText" returns incorrect value when document is open in multiple sessions (e.g. collaborative mode)

[volpav]

Noticed this when playing around with the tool.

Steps to reproduce:

1. Open a document in a new browser tab and select a piece of text;
2. Observe googleDocsUtil.getGoogleDocument().selectedText returning the correct selection;
3. Open the same document in a different browser tab (keep the current tab open), navigate to it;
4. Select another piece of text which appears after the one which is already selected in a first tab;
5. Observe googleDocsUtil.getGoogleDocument().selectedText still returning the text selected in a first tab, even when the code is executed in a second tab;

By looking at the DOM, there doesn't seem to be a great way to distinguish between the two selections (i.e. to determine which one is from the current session).

[LeZuse]

I can reproduce the same issue.

[LeZuse]

From my observation it seems like the active user's highlight does not have a background color set when active, and then on blur it gets set to RGB(0,0,0). Additionally, highlights from other tabs seem to have some gradual fading feature meaning their opacity value is decreasing overtime. That is how they achieve a "recency" feature which collapses the highlight to a carret when the opacity reaches 0.

EDIT:
I suppose that tweaking the query for the selection DIV to filter for the right css values might do the trick: https://github.com/JensPLarsen/ChromeExtension-GoogleDocsUtil/blob/master/googleDocsUtil.js#L61

[bdvorianov]

Working on it now in free time, wait for the releases in future. 👌🏻