gtk:icon-view-path-at-pos (view x y)

view -- a gtk:icon-view widget
x -- an integer with the x position to be identified
y -- an integer with the y position to be identified

The gtk:tree-path instance corresponding to the icon or nil if no icon exists at that position.

Finds the path at the point (x,y), relative to the GDK window coordinates. See the gtk:icon-view-item-at-pos function, if you are also interested in the cell at the specified position. See the gtk:icon-view-convert-widget-to-bin-window-coords function for converting widget coordinates to bin window coordinates.