grouping feature: are there plans to add additional styles for selection checkbox?

If grouping and selection features uses together, selection checkbox doesn't have any condition for state. If some rows selected in group or not selected, or all selected it always show as 'not checked'.

I have tried to replace selectionRowHeaderButtons template in $templateCashe vs my custom directive and done additional logic for ng-class and it's working good, but without search/filtering, With filtering grid re-rendering rows with own internal logic and it's hard to maintain.

I posted this question on stackoverflow and to gitter but nobody replied on this.

It will be good to have states:

• all row selected
• some rows selected
• no rows selected/all rows unselected

Perhaps somebody has already resolved this case. Thanks.