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

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.

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

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 CWundef else returns CW$self

Reads the table into the CWdat 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 CWdata 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. Handles the default type of <data> for those tables which aren't subclassed

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 CWupdate 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

Releases ALL of the memory used by this table, and all of its component/child objects. This method is called automatically by 'CWFont::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 'CWrelease()' 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 CWFont::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 CWFont::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 Martin_Hosken@sil.org. See Font::TTF::Font for copyright and licensing.