PDF::Builder::Basic::PDF::Objind - PDF indirect object reference.
Also acts as an abstract superclass for all elements in a PDF file.
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.
- PDF::Builder::Basic::PDF::Objind->new()
- Creates a new indirect object
- $UID = $r->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::Builder::Basic::PDF::File->release"'
(so you don't have to call it yourself).
Note: 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.
- $value = $r->val()
- Returns the value 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.
- $v = $r->outobjdeep($fh, $pdf)
- If you really want to output this object, then you need to read it first.
This also means that all direct subclasses must subclass this method, or
they will loop forever!
- $r->outobj($fh, $pdf)
- 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.
- $s = $r->elements()
- Abstract superclass function filler. Returns self here but should return
something more useful if an array.
The old name of this method,
"elementsof", has been
deprecated and will be removed in the future.
- $s = $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.
- $o = $r->merge($objind)
- This merges content information into an object reference placeholder. 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
placeholder.
- $r->is_obj($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.