libcapsppd.c File Reference

Handle the options from a PPD file in a dynamic table/array. More...

Macros
#define	INCREMENT_STEP   50
#define	MARGIN   1.5

Functions
static void	exit_libpaper (void)
void	caps_libppd_init (void)
void	caps_libppd_version_get (unsigned *major, unsigned *minor, unsigned *micro)
static void	init_caps_ppd_option (struct caps_ppd_option *o)
static void	free_caps_ppd_option (struct caps_ppd_option *o)
static struct caps_ppd_option *	create_new_option_entry (struct caps_ppd_options_table *pot)
static void	print_caps_ppd_option (const struct caps_ppd_option *o)
struct caps_ppd_option *	caps_ppd_option_get (const struct caps_ppd_options_table *pot, const char *keyword)
struct caps_ppd_option *	caps_ppd_option_with_name_get (const struct caps_ppd_options_table *pot, const char *keyword, const char *name)
void	caps_ppd_option_add (struct caps_ppd_options_table *pot, const char *keyword, const char *name, const char *description, const char *value)
struct caps_ppd_options_table *	caps_ppd_options_table_create (void)
void	caps_ppd_options_table_clean_up (struct caps_ppd_options_table *pot)
const struct caps_ppd_option *	caps_ppd_options_table_base_get (const struct caps_ppd_options_table *pot)
size_t	caps_ppd_options_table_element_count_get (const struct caps_ppd_options_table *pot)
struct caps_ppd_options_table *	caps_ppd_options_table_duplicate (const struct caps_ppd_options_table *src)
int	caps_ppd_paper_format_validate (const char *paper_name)
struct caps_rect	caps_ppd_paper_format_size_get (const char *paper_name)
static int	check_one_edge (double has, double expected)
static const struct paper *	medium_name_and_size_guess (const struct caps_rect *sz)
const char *	caps_ppd_paper_format_name_get (const struct caps_rect *size)
const char *	caps_ppd_paper_default_format_get (void)

Variables
static const struct caps_table_desc	ppd_option_desc

Detailed Description

The data extracted from a PPD file will be handled as a simple table of option data. Each element in the table stores the values:

• keyword (aka "main keyword")
• name (aka "option keyword")
• description (aka "translation")
• value

After some experience with this kind of data I found out, there is no need for any special handling of the PPD's data. All the data from the PPD can be stored in the simple table line per line. No magic required.

National Language Support: When creating the PPD all 'descriptive' strings can be translated to the local language by default. This will be done in a server local manner, not locally at client side. In order to do so, mark all your decriptions strings for NLS and provide a .po file in your printing driver using the libcapsppd library. And provide your "domain name" in the struct caps_ppd_base element domain_name.

Macro Definition Documentation

INCREMENT_STEP

#define INCREMENT_STEP   50

Whenever the option elements in the table are exhausted, enlarge it by 50 new elements.

MARGIN

#define MARGIN   1.5

Function Documentation

exit_libpaper()

static void exit_libpaper ( void  )

static

Just a clean up of the external libpaper

init_caps_ppd_option()

static void init_caps_ppd_option ( struct caps_ppd_option *  o )

static

Every new option structure starts empty

Parameters

[in,out]

o

The option to init

free_caps_ppd_option()

static void free_caps_ppd_option ( struct caps_ppd_option *  o )

static

Free option structure resources

Parameters

[in,out]

o

The option to free

All content is dynamically allocated. Simply free it and be paranoid and reset the content as well.

create_new_option_entry()

static struct caps_ppd_option * create_new_option_entry ( struct caps_ppd_options_table *  pot )

static

"Create" a new option structure

Parameters

[in,out]

pot

Return values

pointer	New option element
NULL	In case of an error

The option structure is part of a dynamic array. Usage of options is expected as a growing amount of options, so for each new option the next free array element is used.

Note

Does not return in case of memory failure

print_caps_ppd_option()

static void print_caps_ppd_option ( const struct caps_ppd_option *  o )

static

check_one_edge()

static int check_one_edge ( double  has, double  expected  )

static

Guess if one edge of the medium matches a format definition

Parameters

[in]	has	The value to check
[in]	expected	The expected value

Return values

1	has is inside the tolerance band of expected
0	No correlation between both sizes

The accepted magin is defined in this function and currently +/- 1.5

Todo:

The margin might be a candidate to be defined in an INI file?

medium_name_and_size_guess()

static const struct paper * medium_name_and_size_guess ( const struct caps_rect *  sz )

static

Goal is to 'guess' the intended medium, not the really given one. In the wild I saw many size variants of DIN A4 for example in PDF files. This function should try to unify them.

libpaper has such a function, but it only matches, if the sizes are exact. What we need is a little bit more tolerance.

This function also checks the rotated coordinates.

Variable Documentation

ppd_option_desc

const struct caps_table_desc ppd_option_desc

static

Initial value:

= {
    .element_sz = sizeof(struct caps_ppd_option),
    .increment =  50 ,
}

Dynamic array handling: we want to manage elemts of struct caps_ppd_option.

Note

Refer Base functions for details.