XmDropSiteQueryStackingOrder man page
XmDropSiteQueryStackingOrder — A Drag and Drop function that returns the parent, a list of children, and the number of children for a specified widget
#include <Xm/DragDrop.h> Status XmDropSiteQueryStackingOrder( Widget widget, Widget *parent_return, Widget **child_returns, Cardinal *num_child_returns);
XmDropSiteQueryStackingOrder obtains the parent, a list of children registered as drop sites, and the number of children registered as drop sites for a given widget. The children are listed in current stacking order, from bottom-most (first child) to the top-most (last child). This function allocates memory for the returned data that must be freed by calling XtFree.
Specifies the widget ID. For this widget, you obtain the list of its children, its parent, and the number of children.
Returns the widget ID of the drop site parent of the specified widget.
Returns a pointer to the list of drop site children associated with the specified widget. The function allocates memory to hold the list. The application is responsible for managing the allocated space. The application can recover the allocated space by calling XtFree.
Returns the number of drop site children for the specified widget.
For a complete definition of DropSite and its associated resources, see XmDropSite(3).
Returns 0 (zero) if the routine fails; returns a nonzero value if it succeeds.
XmDropSite(3) and XmDropSiteConfigureStackingOrder(3).