Getting the Width of an Autosize Label @ Runtime

rbuser

Hi,

I am hoping to find a way to determine the width of an autosized TppLabel in
the BeforePrint event at runtime.

I'm printing address labels, and if any address lines are to long to fit on
the label at the standard font size, I want to decrease the font size until
it does fit. I've tried just changing the font size in the event, but the
the TppLabel component does not resize itself at print time.

Is there any way that I can get a handle to the actual canvas that the
TppReport is drawing on? Then I could use TCanvas.TextWidth('zyx') to get
the width information I need.

thanks,
Bill.

nicocizik

Hi Bill,

It is possible to access the Printer canvas simply by including the
ppPrintr.pas file in your uses clause, then accessing the ppPrinter.Canvas
property. If you prefer to use screen units, you can get access to the
canvas used with the screen device by accessing the
TppViewer.ScreenDevice.Canvas property. You will need to include the
ppViewr.pas file in your uses clause and type cast Report.PreviewForm.Viewer
as a TppViewer.

--

rbuser

Hi Nico,

Thanks for your quick response! I'm certain that i'll find uses for the
various canvases.
However I've managed to get the TppLabel to "AdjustBounds" at runtime by
setting
the TppReport.Printing property to false momentarily during the BeforePrint
event like this:

procedure TMyDataModule.ReportBeforePrint(Sender:TObject);
begin
MyLabel.Caption := 'Some Extra Long Line Of Text';
MyLabel.Font.Height := cStandardHeight;

// Cause TppLabel.AdjustBounds to fire.
Report.Printing := False;
try
MyLabel.AutoSize := False;
MyLabel.AutoSize := True;
finally
Report.Printing := True;
end;

if MyLabel.Width > cMaxLabelWidth then begin
MyLabel.Font.Height := CalculateASmallerFontHeightHere();
end;

end;

It seems to work, but do you forsee any problems with this "hack" technique
of setting
Report.Printing manually?

thanks,
Bill.

nicocizik

Hi Bill,

The method you use below is probably not the safest way to go about changing
the properties of a report component. By setting the Report.Printing
property yourself, you may be altering some of the report engine processes
which in the future as your report becomes more sophisticated, could cause
issues. For now, I would say if it works, don't fix it, but keep this in
mind if other issues begin to arise in the future.

--