Name

XSaveContext, XFindContext, XDeleteContext, XUniqueContext − associative look-up routines

Syntax

int XSaveContext(display, w, context, data)
   Display *display;
   Window w;
   XContext context;
   caddr_t data;

int XFindContext(display, w, context, data_return)
   Display *display;
   Window w;
   XContext context;
   caddr_t *data_return;

int XDeleteContext(display, w, context)
   Display *display;
   Window w;
   XContext context;

XContext XUniqueContext()

Arguments

contextSpecifies the context type to which the data belongs. 

dataSpecifies the data to be associated with the window and type. 

data_returnReturns a pointer to the data. 

displaySpecifies the connection to the X server. 

wSpecifies the window with which the data is associated. 

Description

If an entry with the specified window and type already exists, XSaveContext overrides it with the specified context. The XSaveContext function returns a nonzero error code if an error has occurred and zero otherwise. Possible errors are XCNOMEM (out of memory).

Because it is a return value, the data is a pointer.  The XFindContext function returns a nonzero error code if an error has occurred and zero otherwise. Possible errors are XCNOENT (context-not-found).

The XDeleteContext function deletes the entry for the given window and type from the data structure. This function returns the same error codes that XFindContext returns if called with the same arguments. XDeleteContext does not free the data whose address was saved.

The XUniqueContext function creates a unique context type that may be used in subsequent calls to XSaveContext.

See Also

X Window System: The Complete Reference, Second Edition, Robert W. Scheifler and James Gettys