Maintaining scroll position after height of body is changed

Question

I am working on a page that has two states: edit mode and normal mode. The user switches between these states by clicking on a toggle button. Triggering edit mode adds more elements to the page (buttons, etc) and thus forces the body element to increase its height.

My issue arises when a user has scrolled down the page and then triggers edit mode - since the page's height has now increased, their current scroll position is lost. I have been trying to find a way through which I can calculate what the new scrollTop should be, but have not been successful.

I've got a jsFiddle as an example of my issue. It automatically scrolls to the third "entry", to simulate a user having scrolled down that far. Clicking the "trigger change" button in the top right hand corner will add more elements to the page, and the scroll position of having the third entry at the top of the page is lost.

I am aware that I could just redo $('body').scrollTop($('.entry:nth-child(3)').offset().top); after the new contents have been added, but I want the scroll position to be remembered for no matter where the user has scrolled to on the page.

http://jsfiddle.net/Jn8wq/2/

Any help is greatly appreciated!

Answer 1

Check this fiddle. http://jsfiddle.net/Jn8wq/4/

I added this

var tempScrollTop = $(window).scrollTop();
//your append logic
$(window).scrollTop(tempScrollTop+9);

You would notice that I added '9' to the scroll position. It suits your requirement in the given fiddle. But when you implement this on your actual site, you would have to calculate the height of new appended divs dynamically and add that height instead of '9'.