Does any cross-platform GUI toolkit have a widget that can handle this with sane defaults?
The problem browser based apps run into is rendering the entire list into the DOM and thus the browser has to lay out the whole thing in order to compute scroll bars and scroll positions.
You can work around this using requestAnimationFrame, large empty padding divs, and inspecting the scroll position to create DOM elements for only things that you compute are visible. At my last job I implemented a web based table that could do 60fps scrolling on 100,000 items that were all dynamically updating using js_of_ocaml and https://github.com/janestreet/incr_dom.
You can do this with JS and HTML. There are some popular small JS libs that do just that.
It works like this: it creates a div with a very big "height" value to get the scrollbar look like there is a long list, and JS just loads in the visible area plus a few items above and below, and reloads data as you scroll. It works very good in Chrome and Firefox, and even okay in IE11.
10/second for 2.5 hours, no pause, no breaks.
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