Callback printer_monitor()

Called, when the framework retrieves the status of the printer. But not always. See below.

• parameter you get
  • framework handle
  • your private data hint
• you can expect as already done
  • the printer is still online and can be accessed
• what you can do
  • everything what is possible with your printer
• what you must do
  • nothing
• values you should return
  • 0 everything is okay, the framework can continue
  • -EBUSY if the printer isn't ready to print somehow
  • -ENODEV if something is really bad with your printer and the framework should terminate.
  • -EINVAL if something is wrong with your printer, but can be recovered. If currently a job is processed it will be canceled

libcapsdriver checks the printer status:

• never, if CAPS_TWEAK_SKIP_STATUS is set, and thus, never calls this callback
• periodically when the printer is idle (e.g. waiting for a job to print) if CAPS_TWEAK_SKIP_STATUS isn't set
• immediately before printing a page (e.g. before calling page_print()) if CAPS_TWEAK_SKIP_STATUS_WHEN_PRINTING and CAPS_TWEAK_SKIP_STATUS aren't set

Whenever it checks the printer's status, it calls the callback only if it detects a ready printer device.

Note

This call interferes with some of the flags from caps_drv_prn_tweaks if set in your driver. E.g. it could be limited or fully disabled by these flags. Be warned about this.

This callback is optional.