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odf-converter-integrator: version 0.2.0 released
11-18-2008
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XtDirectConvert() XtDirectConvert()
Name
XtDirectConvert - explicitly invoke an "old-style" resource converter and cache result.
Synopsis
void XtDirectConvert(converter, args, num_args, from, to_return)
XtConverter converter;
XrmValuePtr args;
Cardinal num_args;
XrmValuePtr from;
XrmValuePtr to_return;
Inputs
converter Specifies the "old-style" conversion procedure to be called.
args Specifies the argument list that contains the additional arguments needed to perform the conversion (often NULL).
num_args Specifies the number of additional arguments (often zero).
from Specifies the value to be converted.
Outputs
to_return Returns the converted value.
Description
XtDirectConvert() looks in the converter cache to see if the named conversion procedure has previously been called with the specified argu-
ments. If so, it sets the cached resource address and size in to_return and returns. If no cached value is found, it sets to_return->addr
to NULL and to_return->size to zero and calls converter with its remaining arguments. The results of the conversion are stored in the
cache and returned in to_return.
If the conversion is successful, to_return->addr will be non-NULL. The data at this address must be copied immediately by the caller,
because it may be in static storage owned by the type converter procedure.
Usage
XtDirectConvert() invokes an "old-style" converter of type XtConverter. In Release 4, more flexible (and incompatible) "new-style" con-
verters of type XtTypeConverter were added. Old-style converters are still in use, and if you have to invoke one explicitly, you must use
XtDirectConvert(). If you are writing your own converter, you should use the new style.
XtConvertAndStore() provides a higher level interface to resource conversion, and is easier to use in most cases. It works with both old-
style and new-style converters.
You do not often need, in applications or widgets, to convert between resource types directly. Generally you can rely on the Intrinsics
resource management code to perform all necessary conversions for you. When writing a resource converter, however, you may find that you
need to invoke another converter.
Structures
typedef struct {
unsigned int size;
XPointer addr;
} XrmValue, *XrmValuePtr;
See Also
XtAppAddConverter(1), XtCallConverter(1), XtConvertAndStore(1), XtSetTypeConverter(1),
XtConverter(2), XtTypeConverter(2).
Xt - Resource Management XtDirectConvert()