The property editor scheme relies on being able to set window properties dynamically: the user changes a value, and the window changes immediately to reflect the new value. Unfortunately, not all properties can be changed dynamically in wxWindows; for example, in Motif, the label position must be given at panel item creation time, because the way the widgets are laid out depend on the label position. The label position cannot then be changed without deleting and recreating the item.
Hence the dialog editor takes two approaches: where values are dynamically settable, this is done. Where they are not, the item is deleted and recreated, after all existing values have been transferred into the parallel wxItemResource object. Therefore in wx_rprop.cc, some of the SetProperty implementations have one or more call to RecreateWindowFromResource.