[Qt-interest] Difference in drawing to a QPixmap VS QPrinter

[Christopher Rasch-Olsen Raa]

Fredag 2. juli 2010 14.14.49 skrev Samuel Gaist :
> On 2 juil. 10, at 14:01, Christopher Rasch-Olsen Raa wrote:
> > Hi,
> > 
> > A requirement for an application I'm working on is that it should
> > write a
> > certain page of text to a .pdf. For that I'm using QPainter with
> > QPrinter and
> > setting the outputformat to Pdf. All is good so far.
> > 
> > However, another requirement is that the application should be able
> > to display
> > a "preview" of the document. I though that the quickest way to
> > achieve that
> > must be to pass a QPixmap to the QPainter (since QPixmap is a
> > paintdevice) and
> > let the same code for painting do it's thing regardless for the
> > 'medium'.
> > 
> > What happens is that I get wildly varying looks on the two
> > documents. The pdf
> > looks fine(-ish. lacking some tweaks) but the image (QPixmap) does
> > not. In the
> > QPixmap the text is way too large.
> > 
> > I use (pixmap/printer)->width() and ->height() to get the width and
> > height of
> > my 'canvas' and position things relative to the edges. When creating
> > the fonts
> > I pass the 'device' (a pixmap or printer) to the font's constructor.
> > Is the
> > something special I need to do to have the font 'scale' in
> > accordance to the
> > size of the available 'canvas'?
> > 
> > Have anyone done this before and have some insight to share?
> 
> Hi,
> 
> I can not help you directly for the QPixmap problem but for what you
> want to achieve you might be interested by QPrintPreviewWidget or
> QPrintPreviewDialog.
> 
> Hope this helps
> Samuel

Thanks for the input, but part of the challenge here is that I need to create 
tumbnails of several different documents at once and display them to the user 
side-by-side in the gui, not in different dialoges.

-- 
Christopher