Expose "isScrolling", "index", etc in the virtual table

[franklixuefei]

• [x] I have searched this repository's issues and believe that this is not a duplicate.

I'm using ...

• [x] React Grid
• [ ] React Chart
• [ ] Vue Grid

Current Behaviour

Currently, users have no way to know if a particular cell is being scrolled, nor the cell's index (which row which column)

Expected Behaviour

Ideally, "isScrolling", "index", etc. can be exposed so that users can leverage that information to optimize their code.

Use Case

In my use case, I have a lot of cells whose content depend on remote data. I would like to know which cells are being scrolled so that I can postpone the remote data retrieval for those cells until cells stop scrolling. This could eliminate a whole bunch of unnecessary remote data requests while the cells are being scrolled and ease the burden of the server, which improves the overall performance.

Environment

• devextreme-reactive: xxx
• react: 16.4.1
• material-ui: 1.4.0

[kvet]

Hi.

Thank you for your suggestion. We will consider your ideas when implementing support for remote data retrieval for visible cells.