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 output.
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 simply output to any
font file being created.
- nocompress
- If set, overrides the font default for WOFF table compression. Is a scalar
integer specifying a table size threshold below which this table will not
be compressed. Set to -1 to never compress; 0 to always compress.
- INFILE
- The read file handle
- OFFSET
- Location of the file in the input file
- LENGTH
- Length in the input directory
- ZLENGTH
- Compressed length of the table if a WOFF font. 0 < ZLENGTH < LENGTH
implies table is compressed.
- 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 anything in the
"dat" 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->minsize()¶
Returns the minimum size this table can be. If it is smaller than this, then the
table must be bad and should be deleted or whatever.
$t->dirty($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 parameters in other tables have been updated accordingly. I.e. by the
end of sending "update" to all the tables, the memory 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 automatically by 'Font::TTF::Font->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.
LICENSING¶
Copyright (c) 1998-2013, SIL International (
http://www.sil.org)
This module is released under the terms of the Artistic License 2.0. For
details, see the full text of the license in the file LICENSE.