[OPEN] [#1387] [4.1.0] Buffered Scrolling grid position issues after using mousewheel

[loueradun]

I am experiencing some issues with the buffered scrolling after using the mouse wheel, and then grabbing the scroll bar to change position.

This can be reproduced on the official examples on the latest ext.net (4.1) here:
https://examples4.ext.net/#/GridPane...red_Scrolling/

Steps to reproduce:
1) Click the first row in the grid
2) Using the mousewheel, scroll to row 300 (do not click the row)
3) Attempt to grab the scrollbar and notice how it jumps to the first row

If you use the mousewheel and then click a row before grabbing the scrollbar the issue doesn't occur.

This looks like an issue specifically related to ext.net as I can't reproduce it here:
https://examples.sencha.com/extjs/5....ffer-grid.html

Anyone have any ideas how I could resolve this issue? We need to used buffered grids as the site is too slow without.

[fabricio.murta]

Hello!

Well, Ext.NET 4.1.0 is based on ExtJS 6.0.2, so a better ExtJS sample would be this: https://examples.sencha.com/extjs/6....ffer-grid.html

But regardless of that, the issue happens and we've logged it under #1387 in our issues tracking service! Thanks for reporting it!