XtConvertAndStore(3Xt)

     NAME
          XtConvertAndStore, XtCallConverter - invoke resource
          converters

     SYNTAX
          Boolean XtConvertAndStore(widget, from_type, from, to_type,
          to_in_out)
              Widget widget;
              String from_type;
              XrmValuePtr from;
              String to_type;
              XrmValuePtr to_in_out;

          void XtCallConverter(dpy, converter, args, num_args, from,
          to_in_out, cache_ref_return)
              Display* dpy;
              XtConverter converter;
              XrmValuePtr args;
              Cardinal num_args;
              XrmValuePtr from;
              XrmValuePtr to_in_out;
              XtCacheRef* cache_ref_return;

     ARGUMENTS
          args      Specifies the argument list that contains the
                    additional arguments needed to perform the
                    conversion, or NULL.

          converter Specifies the conversion procedure that is to be
                    called.

          from      Specifies the value to be converted.

          from_type Specifies the source type.

          num_args  Specifies the number of additional arguments
                    (often zero).

          to_type   Specifies the destination type.

          to_in_out Returns the converted value.

          widget    Specifies the widget to use for additional
                    arguments, if any are needed, and the destroy
                    callback list.

          dpy       Specifies the display with which the conversion is
                    to be associated.

     DESCRIPTION
          The XtConvertAndStore function looks up the type converter
          registered to convert from_type to to_type, computes any
          additional arguments needed, and then calls XtCallConverter.
          (or XtDirectConvert if an old-style converter was registered
          with XtAddConverter or XtAppAddConverter.  ) with the from
          and to_in_out arguments.

          The XtCallConverter function looks up the specified type
          converter in the application context associated with the
          display and, if the converter was not registered or was
          registered with cache type XtCacheAll or XtCacheByDisplay
          looks in the conversion cache to see if this conversion
          procedure has been called with the specified conversion
          arguments. If so, it checks the success status of the prior
          call, and if the conversion failed, XtCallConverter returns
          False immediately; otherwise it checks the size specified in
          the to argument and, if it is greater than or equal to the
          size stored in the cache, copies the information stored in
          the cache into the location specified by to->addr, stores
          the cache size into to->size, and returns True.  If the size
          specified in the to argument is smaller than the size stored
          in the cache, XtCallConverter copies the cache size into the
          to->size and returns False.  If the converter was registered
          with cache type XtCacheNone or no value was found in the
          conversion cache, XtCallConverter calls the converter and,
          if it was not registered with cache type XtCacheNone, enters
          the result into the cache.  XtCallConverter then returns
          what the converter returned.

          The cache_ref_return field specifies storage allocated by
          the caller in which an opaque value will be stored. If the
          type converter has been registered with the XtCacheRefCount
          modifier and if the value returned in in cache_ref_return is
          non-NULL, then the call should store the cache_ref_return
          value in order to decrement the reference count when the
          converted value is no longer required. The cache_ref_return
          argument should be ULL if the caller is unwilling or unable
          to store the value.

     SEE ALSO
          XtAppReleaseCacheRefs(3Xt)
          X Toolkit Intrinsics - C Language Interface
          Xlib - C Language X Interface