toolbar text input grid filter

I’ve got a toolbar above a grid. The toolbar contains a text input item that I want to use as a Filter input for all grid columns. I need to trap a timed-text-input event, like the grid header filters do.

You may use the following approach to get input object (itemId is the id if the input button):

var inputObj = toolbar.objPull[toolbar.idPrefix+itemId].obj.firstChild

And create a filter:

grid.makeFilter(inputObj,columnIndex);

Here is the article in the documentation:
docs.dhtmlx.com/doku.php?id=dhtmlxgrid:filtering