Suggestion - split-pane

Hi all,
some how, the resizeable grid doesnt work for me, the core of some browser maynot support it.
so I really suggest to add ‘split-pane’ in next F7.

I guess a full js/jq type resizeable thing is a good way…

here is resause:

Yes, I need to this. I was also thinking about a fixed splitPane where uppermost is fixed at top.