LabWindows/CVI Release Notes for Windows
18
©
National Instruments Corporation
By using direct Windows printing, you can take full advantage of the higher resolution
printers have over computer screens. This allows panels and controls to be scaled optimally
to the printer coordinates, thus eliminating the aliasing that causes blocky text and graph
plots. On the other hand, certain printers do not support the raster operations necessary for
printing certain kinds of objects. Specifically, many printers are not capable of printing
transparent bitmaps.
Revised Print Dialog Boxes on Windows
For programmatic printing and printing from the File menu, a common, unified print dialog
box allows you to do the following:
•
Select a printer.
•
Specify printing options that are specific to LabWindows/CVI. Different sets of options
appear for graphics printing as opposed to text printing.
•
Open the standard Windows dialog box for the selected printer. You set options that are
specific to the printer in this dialog box.
You can programmatically set all the options that are specific to LabWindows/CVI by using
SetPrintAttribute
in LabWindows/CVI. In addition, you can programmatically set some
of the attributes in the printer-specific dialog box using
SetPrintAttribute
.
Interaction between Print Dialog Boxes and Programmatic Attributes
LabWindows/CVI 5.0 modifies the way the print dialog boxes interact with attributes when
used in a program.
Previously, if you selected a different printer in the dialog box, the User Interface Library
did not retain the name of the selected printer. Every time the print dialog box appeared,
the printer selection was reset to the current system printer. Now, the library stores the
name of the printer you select in a new attribute,
ATTR_PRINTER_NAME
. Whenever the print
dialog box appears, LabWindows/CVI sets the printer selection to the current value of
ATTR_PRINTER_NAME
. If
ATTR_PRINTER_NAME
is
NULL
, the empty string, or the name of a
printer that is not currently known by Windows, the next call to a printing function uses the
current system printer and stores its name as the
ATTR_PRINTER_NAME
value.
Normally, when the user invokes the common print dialog box or the printer-specific dialog
box, LabWindows/CVI initializes the controls that correspond to programmatic attributes to
the current attribute values. The new value
VAL_USE_PRINTER_SETTING
allows you to
initialize the printer-specific dialog box to the current system values for the printer rather
than the current values of the User Interface Library attributes. You can access the system
values for the printer in the Control Panel. When the user clicks on OK in the dialog box,
LabWindows/CVI copies the current values in the controls to the attributes.
LabWindows/CVI does not retain the
VAL_USE_PRINTER_SETTING
value.
Refer to the following
Using Windows System Printer Settings
section for more information
on
VAL_USE_PRINTER_SETTING
.
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