Catching check all events

I’m using a grid with a checkbox column and a header of #master_checkbox so users can select all the items if desired. I also need to catch checked events to I can update a count of checked items that I am displaying. The onCheckBox and onCheck events both seem to fire when a checkbox is checked or unchecked but don’t work when the master checkbox in the header is checked. How can I catch that event so I can correctly update the count of checked items?

By default “onCheckbox” event is not called when you check “master_checkbox” in the header. If you want add “oncheck” event handler for “master_checkbox” it can be done only with code modifications:
In the file dhtmlxgrid_filter.js:

var self=this;
//any custom code here