Gtk.ToolButton.prototype.set_icon_widget

function set_icon_widget(icon_widget:Gtk.Widget):void {
    // Gjs wrapper for gtk_tool_button_set_icon_widget()
}

Sets @icon as the widget used as icon on button. If icon_widget is null the icon is determined by the "stock_id" property. If the "stock_id" property is also null, button will not have an icon.

Since 2.4