HTML code - how to find out absolute position on the page?

Question

Is there any browser engine or plugin which would give user information about position of given HTML element ? I want to know where is element located e.g. left corner or center of the page.

It should not be a huge problem as Firefox and Chrome marks you elements within page as you go through html code in Developer Tools > "Element tab".

Example of highlighted element : http://imgur.com/mUHd51q we see that selected element is currently in the centre of the screen - how to get this information programatically ?

Answer 1

Selenium-webdriver can give you information about any DOM element you want:

d = Selenium::WebDriver.for :chrome
d.get "http://www.google.com"
elem = d.find_element(:name, "btnI")
elem.location
=> #<struct Selenium::WebDriver::Point x=532, y=356>