Grid content disappear when dragging scrollbar on big data sets

[JoeOM]

Hi

I love SlickGrid, but unfortunately, the content disappears when you drag the scrollbar adjuster with big datasets. This does not happen in a few other grids which make me think it can also be done in SlickGrid.

DevExpress React grid, for example, does not seem to have this issue...

https://devexpress.github.io/devextreme-reactive/react/grid/demos/featured/virtual-scrolling/

Could the community maybe look into this?

Thank you very much guys!

[6pac]

Yeah, I think we've talked about some kind of rate limiting before. I think the events just pile up, and most could be discarded.

The difference between those grids and this one, though, is that they're professionally developed, this one is purely volunteer, and we're all quite busy!

So I'll put this on the 'todo' list. I'm trying to get a web site together for SlickGrid, partly to marshal the community more effectively and make use of those valuable people who might have time to just play with things like this and come up with a viable solution. Sorry I can't do better.

[ghiscoding]

@6pac
while converting SlickGrid to TypeScript I found that the reason why we always see white section when scrolling large dataset is because of this scroll throttling shown below

SlickGrid/slick.grid.js

Line 237 in 4b06690

var scrollThrottle = ActionThrottle(render, 50);

which is used in the action throttle

SlickGrid/slick.grid.js

Lines 4464 to 4468 in 4b06690

	function blockAndExecute() {
	blocked = true;
	setTimeout(unblock, minPeriod_ms);
	action();
	}

it looks like you were the person who made this change via this commit
93f043f

do you know why we have to use 50 as a throttling? perhaps we could keep the 50 as default but also provide a grid option? with a grid option we could let the user try for themselves. I tried with 0 throttling and it does seem to cause some kind of UI issues or flickering but using 5 seems like a good number, for example below is with a throttling of 5

BTW, this is the new styling theme 😉

versus the hard coded throttling of 50 which we see the white section appears much more and longer, 50ms seems like a long time for the user to wait for re-rendering

[6pac]

No recollection of doing this at all (and no commend in the commit :-/ ). Happy with a settable delay and a change to the default.

[ghiscoding]

ok I'll add it to the TypeScript version only for now, if we ever have other fixes to commit on current version then I could backport it if need be.

[ghiscoding]

improvements were made in v5.0, see SlickGrid 5.0 Announcement and Migration