ThumbnailProcedure

Creates a new thumbnail procedure named name which will call run_func when invoked.

See Procedure for information about proc_type.

ThumbnailProcedure is a Procedure subclass that makes it easier to write file thumbnail procedures.

It automatically adds the standard

(File, size)

arguments and the standard

(Image, image-width, image-height, ImageType, num-layers)

return value of a thumbnail procedure. It is possible to add additional arguments.

When invoked via run, it unpacks these standard arguments and calls run_func which is a RunThumbnailFunc. The "args" ValueArray of RunThumbnailFunc only contains additionally added arguments.

RunThumbnailFunc must truncate the returned ValueArray to the number of return values it actually uses.

Parameters:

plug_in	a PlugIn.
name	the new procedure's name.
proc_type	the new procedure's PDBProcType.
run_func	the run function for the new procedure.
run_data	user data passed to run_func.
run_data_destroy	free function for run_data, or null.

Returns:

a new Procedure.