A printer control panel is a DLL written to display the current status of a printer. Optionally, this DLL also allows a user to change the front panel settings for a printer that can communicate bidirectionally with the OS/2 print subsystem.

This printer panel DLL is called when the user selects the "Printer Panel" menu item on a print object that is connected to a printer communicating bidirectionally with the OS/2 print subsystem.

The file type of a printer control panel is ".DLL". The printer control panels make use of the PrtQuery and PrtSet APIs to get current status of printers. See the "Bidirectional Communications" chapter in the Printer Device Driver Reference for OS/2 for more information.

The functions exported from a printer control panel are as follows:

• SplQueryControlPanel
  
• SplRegisterControlPanel

A protocol converter is installed in a system by calling SplRegisterControlPanel. This adds the following entry to the system .INI file:

AppName =

PM_SPOOLER_CONTROL_PANEL

ControlPanelName Example: "NewPrinter"

Path to DLL with ctrl panel
Example: "C:\OS2\DLL\CPANEL.DLL"

The print object typically calls SplGetControlPanelList, which causes the spooler to call the API SplQueryControlPanel for each installed printer control panel, in order to determine if the printer panel DLL can display a control panel for the given printer.

The print object gives the list of printer panel names to the user and, after one is selected, the print object will call SplDisplayControlPanel.