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
function looks up the type converter registered to convert from_type
to to_type, computes any additional arguments needed, and then calls
(or
if an old-style converter was registered with
or
) with the from and to_in_out arguments.
The
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
or
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,
returns
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
If the size specified in the to argument is smaller than the size
stored in the cache,
copies the cache size into the to->size and returns
If the converter was registered with cache type
or no value was found in the conversion cache,
calls the converter and, if it was not registered with cache type
enters the result into the cache.
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
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(3Xt)
