Section: User Contributed Perl Documentation (3)
Font::TTF::Table - Superclass for tables and used for tables we don't have a class for
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 start with a space
Flag which indicates that the table has already been read from file.
Allows the creation of unspecific tables. Data is simply output to any font
file being created.
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.
The read file handle
Location of the file in the input file
Length in the input directory
Compressed length of the table if a WOFF font. 0 < ZLENGTH < LENGTH implies table is compressed.
Checksum read from the input file's directory
The Font::TTF::Font that table is part of
Creates a new table or subclass. Table instance variables are passed in
at this point as an associative array.
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
else returns $self
For WOFF-compressed tables, the table is first decompressed and a
replacement file handle is created for reading the decompressed data. In this
case ORIGINALOFFSET will preserve the original value of OFFSET for
applications that care.
Reads the table into the "dat"
instance variable for those tables which don't
know any better
Writes out the table to the font file. If there is anything in the
instance variable then this is output, otherwise the data is copied
from the input file to the output
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
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
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.
This sets the dirty flag to the given value or 1 if no given value. It returns the
value of the flag
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.
Clears a table of all data to the level of not having been read
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.
No known bugs
Martin Hosken <http://scripts.sil.org/FontUtils
Copyright (c) 1998-2016, SIL
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.