NAME¶
PDF::API2::Basic::PDF::Objind - PDF indirect object reference. Also acts as an
abstract superclass for all elements in a PDF file.
INSTANCE VARIABLES¶
Instance variables differ from content variables in that they all start with a
space.
- parent
- For an object which is a reference to an object in some
source, this holds the reference to the source object, so that should the
reference have to be de-referenced, then we know where to go and get the
info.
- objnum (R)
- The object number in the source (only for object
references)
- objgen (R)
- The object generation in the source
There are other instance variables which are used by the parent for file
control.
- isfree
- This marks whether the object is in the free list and
available for re-use as another object elsewhere in the file.
- nextfree
- Holds a direct reference to the next free object in the
free list.
METHODS¶
PDF::API2::Basic::PDF::Objind->new()¶
Creates a new indirect object
uid¶
Returns a Unique id for this object, creating one if it didn't have one before
$r->release¶
Releases ALL of the memory used by this indirect object, and all of its
component/child objects. This method is called automatically by
'"PDF::API2::Basic::PDF::File->release"' (so you don't have to
call it yourself).
NOTE, that it is important that this method get called at some point
prior to the actual destruction of the object. Internally, PDF files have an
enormous amount of cross-references and this causes circular references within
our own internal data structures. Calling '"release()"' forces these
circular references to be cleaned up and the entire internal data structure
purged.
Developer note: As part of the brute-force cleanup done here, this method
will throw a warning message whenever unexpected key values are found within
the "PDF::API2::Basic::PDF::Objind" object. This is done to help
ensure that unexpected and unfreed values are brought to your attention, so
you can bug us to keep the module updated properly; otherwise the potential
for memory leaks due to dangling circular references will exist.
$r->val¶
Returns the val of this object or reads the object and then returns its value.
Note that all direct subclasses *must* make their own versions of this
subroutine otherwise we could be in for a very deep loop!
$r->realise¶
Makes sure that the object is fully read in, etc.
$r->outobjdeep($fh, $pdf)¶
If you really want to output this object, then you must need to read it first.
This also means that all direct subclasses must subclass this method or loop
forever!
$r->outobj($fh)¶
If this is a full object then outputs a reference to the object, otherwise calls
outobjdeep to output the contents of the object at this point.
$r->elementsof¶
Abstract superclass function filler. Returns self here but should return
something more useful if an array.
$r->empty¶
Empties all content from this object to free up memory or to be read to pass the
object into the free list. Simplistically undefs all instance variables other
than object number and generation.
$r->merge($objind)¶
This merges content information into an object reference place-holder. This
occurs when an object reference is read before the object definition and the
information in the read data needs to be merged into the object place-holder
$r->is_obj($pdf)¶
Returns whether this object is a full object with its own object number or
whether it is purely a sub-object. $pdf indicates which output file we are
concerned that the object is an object in.
$r->copy($pdf, $res)¶
Returns a new copy of this object. The object is assumed to be some kind of
associative array and the copy is a deep copy for elements which are not PDF
objects, according to $pdf, and shallow copy for those that are. Notice that
calling "copy" on an object forces at least a one level copy even if
it is a PDF object. The returned object loses its PDF object status though.
If $res is defined then the copy goes into that object rather than creating a
new one. It is up to the caller to bless $res, etc. Notice that elements from
$self are not copied into $res if there is already an entry for them existing
in $res.