font::ttf::tabluser contributed perl documentafont::ttf::table(3)
NAME
Font::TTF::Table - Superclass for tables and used for
tables we don't have a class for
DESCRIPTION
- Looks after the purely table aspects of a TTF table, such
as whether the table has been read before, locating the
file pointer, etc. Also copies tables from input to out
put. - INSTANCE VARIABLES
Instance variables start with a space - read
- Flag which indicates that the table has already been
read from file. - dat Allows the creation of unspecific tables. Data is sim
- ply output to any font file being created.
- INFILE
- The read file handle
- OFFSET
- Location of the file in the input file
- LENGTH
- Length in the input directory
- CSUM
- Checksum read from the input file's directory
- PARENT
- The Font::TTF::Font that table is part of
METHODS
Font::TTF::Table->new(%parms)
Creates a new table or subclass. Table instance variables
are passed in at this point as an associative array.
$t->read
Reads the table from the input file. Acts as a superclass
to all true tables. This method marks the table as read
and then just sets the input file pointer but does not
read any data. If the table has already been read, then
returns "undef" else returns $self
$t->read_dat
Reads the table into the "dat" instance variable for those
tables which don't know any better
$t->out($fh)
Writes out the table to the font file. If there is any
thing in the "data" instance variable then this is output,
otherwise the data is copied from the input file to the
output
$t->out_xml($context)
Outputs this table in XML format. The table is first read
(if not already read) and then if there is no subclass,
then the data is dumped as hex data
$t->XML_element
Output a particular element based on its contents.
$t->XML_end($context, $tag, %attrs)
Handles the default type of <data> for those tables which
aren't subclassed
$t->dirty($val)
This sets the dirty flag to the given value or 1 if no
given value. It returns the value of the flag
$t->update
Each table knows how to update itself. This consists of
doing whatever work is required to ensure that the memory
version of the table is consistent and that other parame
ters in other tables have been updated accordingly. I.e.
by the end of sending "update" to all the tables, the mem
ory version of the font should be entirely consistent.
Some tables which do no work indicate to themselves the
need to update themselves by setting isDirty above 1. This
method resets that accordingly.
$t->empty
Clears a table of all data to the level of not having been
read
$t->release
Releases ALL of the memory used by this table, and all of
its component/child objects. This method is called auto
matically by '"Font::TTF::Font-E<GT>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, we track things in a structure that can result
in circular references, and without calling '"release()"'
these will not properly get cleaned up by Perl. Once this
method has been called, though, don't expect to be able to
do anything with the "Font::TTF::Table" object; it'll have
no internal state whatsoever.
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
"Font::TTF::Table" object. This is done to help ensure
that any unexpected and unfreed values are brought to your
attention so that you can bug us to keep the module
updated properly; otherwise the potential for memory leaks
due to dangling circular references will exist.
BUGS
No known bugs
AUTHOR
- Martin Hosken Martin_Hosken@sil.org. See Font::TTF::Font
for copyright and licensing.