Identifying Between Refresh And Close Browser Actions

Question

When we refresh the page (F5, or icon in browser), it will first trigger ONUNLOAD event. When we close the browser (X on right top icon),It will trigger ONUNLOAD event. Now

Answer 1

Unfortunately inspecting the clientY/pageY value of the event, as suggested by some of the answers here, is not a reliable way to determine if the unload event is being fired by as a consequence of the user closing the page.

The reason clientY/pageY is negative when you click the browser's close button is because the close button is positioned above the top of the document (i.e. above pixel 0), but so is the reload button meaning that clicking the reload button will also result in a negative value for clientY/pageY.

Going down the path of inspecting the x co-ordinate of the event is also problematic because the browser close button is not always on the right hand side of the window (e.g. it's on the left in OS X) and because a window can be closed by closing its tab or via the keyboard.