NAME

       XtConvertAndStore, XtCallConverter - invoke resource converters

SYNTAX

       #include <X11/Intrinsic.h>

       Boolean  XtConvertAndStore(Widget  widget,  const char *from_type, XrmValuePtr from, const char *to_type,
              XrmValuePtr to_in_out);

       Boolean XtCallConverter(Display* dpy, XtTypeConverter 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 NULL if the caller is unwilling or unable to store the value.

SEE ALSO

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

X Version 11                                       libXt 1.2.1                              XtConvertAndStore(3)