[Solved] Controling text size to virtual printer
lazarus / 39-Graphics

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emaza · 2014-07-10 00:50

Hi. I hope this is the right topic group. I am using
Printer.Canvas.TextOut to print reports from my program. All initial
problems when changing fonts etc solved after some research by using
Abs(2* Printer.Canvas.Font.Height) for space between print lines, and
a factor of Round(Printer.PageWidth/215) to set the aprox horizontal
position in millimeters –limiting printing to 8.5 inch wide paper-
which is ok with me for now.

I am still using Windows XP, and programming either the PrintDialog or
PrinterSetupDialog (see no dif between these) the user can select a
real printer or two virtual options to print to file: Microsoft Office
Document Image Writer OR Microsoft XPS Document Writer. With the
options mentioned above all three options work fine. The problem is
this: If after printing a document the user changes from, or to, the
virtual Image (TIF) printer, the text size is altered in the second
document. Result is then either an extremely small text in the XPS
report (everything else, including column positions ok) or extremely
large text on the TIF report. Closing the program and running again
resets printing for as long as the printer is not changed again. No
idea if any of this would work if ported to Lynux.

Seems to me (no expert) that there should be some command that could
be placed after printing or before printing to avoid this, but after a
week of searching learned a lot about “Scaling”, DPI Aware
applications, etc, but found no solution I could implement. Will
appreciate help.

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marcov · 2014-07-10 07:41

IIRC query the virtual printer size for DPI settings, and adjust using
them.  It has been over 10 years that I did this at a previous
employer's, so I don't have code.

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emaza · 2014-07-10 20:46

Thanks Marcov. Very unsure about what data to query, how to query, and
how to adjust, so was looking for some way to make windows
automatically do it again as it does on the first loop. Had tried some
code using “Printer.Canvas.Font.PixelsPerInch” and “Printer.XDPI”
which did not work. After reading your advice I tried this:

If Printer.PrinterName='Microsoft Office Document Image Writer' then
Printer.Canvas.Font.Height := -22;

If Printer.PrinterName='Microsoft XPS Document Writer' then
Printer.Canvas.Font.Height := -67;

This to my surprise worked. It is an ugly temporary solution which
probably only works for the Font I have set, but good for me now, to
improve later. Thanks very much for pointing me in the right path. I
will mark this as solved, although all further answers are welcome.

PS: I had to google “IIRC” to find what it meant. I thought it was a
type of Pascal Query!   Thanks again.