qlmedia.c File Reference

Common routines to deal with DK rolls for QL label printers. More...

Functions
static const struct dk_roll_types *	ql_dk_element_get (const char *name)
int	ql_dk_information_get (struct dk_roll_types *medium, const char *name)
int	ql_input_raster_crop (struct qldriver *ql)

Variables
static const struct dk_roll_types	rolls []

Detailed Description

Common routines to deal with DK rolls for QL label printers.

Copyright

GNU General Public License 2.0 or later

Author

Jürgen Borleis

Media handling in QL label printers is a little bit confusing. The printers have some - lets call it 'interesting' - behaviour when dealing with continuous and pre-cut labels. The differences should be handled here.

Function Documentation

ql_dk_element_get()

static const struct dk_roll_types* ql_dk_element_get ( const char *  name )

static

Loop through the list of rolls and search for a specific one

Parameters

[in]

name

The DK roll name to search for

Return values

Pointer	The corresponding roll element
NULL	name not found

ql_dk_information_get()

int ql_dk_information_get	(	struct dk_roll_types *	medium,
		const char *	name
	)

Retrieve settings/information about a specific DK roll/cassette

Parameters

[out]	medium	The settings for the DK roll named by name
[in]	name	The DK roll name the settings should be retrieved for

Return values

0	On success, *medium is valid
-EINVAL	Roll with the given name not found

DK rolls can inherit settings from other rolls. This routine walks through the table and uses the dk_roll_types::like member to re-use their settings.

ql_input_raster_crop()

int ql_input_raster_crop

(

struct qldriver *

ql

)

Crop the input raster to meet the printer's expectations/requirements

Parameters

[in]

ql

Full job description

The printer device has some - hmm, lets it call - interesting requirements about the print data it accepts. Continuous labels are easy, but pre-cut labels aren't. In order to ensure the printer always cuts inbetween two pre-cut labels, we need to tweak the amount of lines to be print.

Read How the Filter deals with margins about details.

Variable Documentation

rolls

const struct dk_roll_types rolls[]

static

List of known DK rolls and their special requirements. At least we need to know here if the DK rolls are continuous or pre-cut. And since the QL8xx printer variants we also need to know, if the DK roll can be used for bi-colour prints.
But most of the time, they are more or less the same from the printer point of view, so the .like member points to a base DK roll type.

Todo:

All transport tape sizes are still to be checked