Called right before an element is destroyed.
int function(Ihandle *ih); [in C] ih:destroy_cb() -> (ret: number) [in Lua]
ih: identifier of the element that activated the event.
If the dialog is visible then it is hidden before it is destroyed. The callback will be called right after it is hidden.
The callback will be called before all other destroy procedures.
For instance, if the element has children then it is called before the children are destroyed.
For language binding implementations use the callback name "LDESTROY_CB" to release memory allocated by the binding for the element. Also the callback will be called before the language callback.