func doGetPreferredSize(data)
	if(linked("onGetPreferredSize"))
		event("onGetPreferredSize", sys.get_obj_name(this.name) + '.GetPreferredSize(' + d("constrainingSize") + ')')
	else
		blk.println(sys.get_obj_name(this.name), '.GetPreferredSize(', d("constrainingSize"), ');')
	end
end