Margins in the printer properties

[Goffioul Michael]

> Ok. See below:
> Appologies if I'm quoting wrong versions of the sources:
> From:
> http://developer.kde.org/documentation/library/3.4-api/kdeprin
> t/html/kpmarginpage_8cpp-source.html
> 
> 00060 void KPMarginPage::initPageSize(const QString& ps, bool 
> landscape)
> 00061 {
> 00062     // first retrieve the Qt values for page size and margins
> 00063     QPrinter    prt(QPrinter::PrinterResolution);
> 00064     prt.setFullPage(true);
> 00065     prt.setPageSize((QPrinter::PageSize)(ps.isEmpty() ? 
> KGlobal::locale()->pageSize() : ps.toInt()));
> 00066     QPaintDeviceMetrics metrics(&prt);
> 00067     float   w = metrics.width();
> 00068     float   h = metrics.height();
> 00069     unsigned int    it, il, ib, ir;
> 00070     prt.margins( &it, &il, &ib, &ir );
> 00071     float   mt = it;
> 00072     float   ml = il;
> 00073     float   mb = ib;
> 00074     float   mr = ir;
> 00075 
> 00076     if (driver() && m_usedriver )
> 00077     {
> 00078         QString pageSize(ps);
> 00079 
> 00080         if (pageSize.isEmpty())
> 00081         {
> 00082             DrListOption    *o = 
> (DrListOption*)driver()->findOption("PageSize");
> 00083             if (o)
> 00084                 pageSize = o->get("default");
> 00085         }
> 00086         if (!pageSize.isEmpty())
> 00087         {
> 00088             DrPageSize  *dps = driver()->findPageSize(pageSize);
> 00089             if (dps)
> 00090             {
> 00091                 w = dps->pageWidth();
> 00092                 h = dps->pageHeight();
> 00093                 mt = QMAX( mt, dps->topMargin() );
> 00094                 ml = QMAX( ml, dps->leftMargin() );
> 00095                 mb = QMAX( mb, dps->bottomMargin() );
> 00096                 mr = QMAX( mr, dps->rightMargin() );
> 00097             }
> 00098         }
> 00099     }
> 00100     m_margin->setPageSize(w, h);
> 00101     m_margin->setOrientation(landscape ? KPrinter::Landscape : 
> KPrinter::Portrait);
> 00102     m_margin->setDefaultMargins( mt, mb, ml, mr );
> 00103     m_margin->setCustomEnabled(false);
> 00104 }
> 
> The interesting part starts at line 00093 there if I 
> understand it correctly 
> it will take the maximum of the settings from the ppd and the 
> setting that 
> come from QPrinter.
> 
> However in qt-x11-free-3.3.5/src/kernel/qprinter_unix.cpp:
> 
> 
> /*!
>     \overload
> 
>     Sets \a top, \a left, \a bottom and \a right to the margins of the
>     printer.  On Unix, this is a best-effort guess, not based on
>     perfect knowledge.
> 
>     If you have called setFullPage( TRUE ), the four values specify
>     the smallest sane margins you can use.
> 
>     If you have called setFullPage( FALSE ) (this is the default),
>     the margins are automatically subtracted from the pageSize() by
>     QPrinter.
> 
>     \sa setFullPage() QPaintDeviceMetrics PageSize
> */
> void QPrinter::margins( uint *top, uint *left, uint *bottom, 
> uint *right ) 
> const
> {
>     if ( !D->marginsSpecified ) {
>         int x = orient == Portrait ? res/2 : res/3;
>         int y = orient == Portrait ? res/3 : res/2;
>         *top = *bottom = y;
>         *left = *right = x;
>     } else {
>         *top = D->topMargin;
>         *left = D->leftMargin;
>         *bottom = D->bottomMargin;
>         *right = D->rightMargin;
>     }
> }
> 
> Afaik the problem is, as D->marginsSpecified gets initialized 
> to false in the 
> QPrinter constructor, the guessing algorithm gets used. In my 
> case the 
> guessed values are larger than the ones from the ppd and in 
> the end it will 
> use the guessed values. Making it impossible for me to 
> exactly position a 
> cdlabel or whatever.
> 
> The question is how to fix. Maybe simply removing the QMAXs 
> would help.
> What do you think?

It's actually a *feature*. You can read the extended reasoning in that
thread: http://lists.kde.org/?t=110607853400003&r=1&w=2
The point is that an application that do not want to print on the whole
page (setFullPage(false)), expects to print with some reasonable margins
by default, even if the PPD files says it can print on the whole page.
However, you should be able to go beyond these reasonable margins by using
an application capable of printing on the whole page (setFullPage(true)),
I think KWord is one.

Michael.