gtk:icon-view-item-width (object)

object -- a gtk:icon-view widget
width -- an integer for the width for each item

The accessor for the item-width slot of the gtk:icon-view class gets or sets the width to use for each item. If it is set to -1, the icon view will automatically determine a suitable item size. The gtk:icon-view implementation is deprecated since 4.10. Use the gtk:grid-view implementation instead.