[Kde-perl] A newbee problem with Pen and CanvasPolygon

Alain EMPAIN alain.empain at ulg.ac.be
Mon Apr 26 18:47:32 CEST 2004


I answer myself :-{


Qt Assistant :
------------------
'Note that QCanvasPolygon does not support an outline (the pen is always
NoPen).'  
-------------------------------------------------------

Is there a way to trace an efficient polyline on a canvas ? ( I want to
avoid to use thousands canvasLine objects !).

I fiddle with Painter within a canvas or a canvas object
(canvasRectangle) but it does not seem to work.

I did not imagine that it is impossible to trace the outline of a
polygon within a canvas ! 
How to trace efficient  XY graphs ?

	Thanks for any advice.

	Alain


On Sun, 2004-04-25 at 15:38, Alain EMPAIN wrote:
> Hello,
> 
> I am discovering canvas, but up to now, I cannot see any Pen drawing
> when I draw a polygon. By the way, filling with the brush is effective.
> 
> Any help will be welcome !
> 
> -------------------------------- 
> (...)
> my $cp; # canvas polygon
> my $pa; # point array
> my $brush;
> my $pen;
> # ------------------------------------
> (..)
> $pen=Qt::Pen( &red, &SolidLine );
> $brush=Qt::Brush( &green, &Dense6Pattern );
> (..)
>  $cp=Qt::CanvasPolygon($canvas);
>  $cp->setBrush($brush);
>  $cp->setPen($pen);
>  $cp->setZ(255);
> 
>  # -- set the point array
>  $pa=Qt::PointArray(15);
>     $pa->setPoint(0,0,0);
>     $pa->setPoint(1,100,100);
>     $pa->setPoint(2,100,200);
>     $pa->setPoint(3,1000,200);
>     $pa->setPoint(4,500,800);
>     $pa->setPoint(5,0,0);
> 
>   # --- load the points into the polygon
>   $cp->setPoints($pa);
>   $cp->show();
> 
>   # --------------
>   $canvas->update();
> (..)
> 
> 
> No error, nice filling pattern but no border.
> 
> 	Thanks,
> 
> 	Alain
-- 
------------------------------------------------------------
Dr Alain Empain  <alain.empain at ulg.ac.be> <alain at br.fgov.be>
      Bioinformatics, Molecular Genetics, 
      Fac. Med. Vet., University of Liège, Belgium
      Bd de Colonster, B43   B-4000 Liège (Sart-Tilman)
WORK: +32 4 366 3821  FAX: +32 4 366 4122
HOME: rue des Martyrs,7  B- 4550 Nandrin       
  +32 85 51 23 41  GSM: +32 497 70 17 64



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