bionic (3) XtConvertAndStore.3.gz

NAME

       XtConvertAndStore, XtCallConverter - invoke resource converters

SYNTAX

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

       Boolean XtCallConverter(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 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