PQ Pro uses native scrollbar and its position can be obtained simply from grid.scrollX() and grid.scrollY() methods.
beforeTableView: function (evt, ui) {
var y = this.scrollY(); //returns vertical position of scrollbar in pixels.
}
However if you are trying to access records position inside the viewport in beforeTableView event.
beforeTableView: function (evt, ui) {
var initV = ui.initV; //returns rowIndx of first rendered row in the unfrozen viewport.
var finalV = ui.finalV; //returns rowIndx of last rendered row in the unfrozen viewport.
}