a #GtkWidget
X position relative to @src_widget
Y position relative to @src_widget
location to store X position relative to @dest_widget
location to store Y position relative to @dest_widget
%FALSE if either widget was not realized, or there was no common ancestor. In this case, nothing is stored in *@dest_x and *@dest_y. Otherwise %TRUE.
Translate coordinates relative to @src_widget’s allocation to coordinates relative to @dest_widget’s allocations. In order to perform this operation, both widgets must be realized, and must share a common toplevel.