[reportlab-users] determine the color of a pixel

[pier carteri]

Yes I agree with you....
This thread has forced me to rethink my program: probably a bit of
refactoring on my code can be the way. I will try to rewrite part of
my app for drawing box and string at the same time.
Thank you all for your time and tips!

Pier

On 10/27/06, Robin Becker <robin at reportlab.com> wrote:
> pier carteri wrote:
> > Yes, sorry, my questions were a bit confused.
> > I will explain my problem in a bit more detail.
> > I' ve a program divided in two parts; the first one composes box on
> > the canvas, the second one draws string. The second part ignores what
> > has been drawed on canvas.
> > A bit of code:
> >
> > from reportlab.pdfgen import canvas
> > c = canvas.Canvas("test.pdf")
> > #first part
> > c.lines([(20,20,60,20),
> >           (20,20,20,40),
> >           (60,20,60,40),
> >           (20,40,60,40),
> >         ])
> > #second part
> > c.drawString(25,25, "Test")
> > c.save()
> >
> > What I would like to obtain is that if the string I'm drawing is
> > inside one of the box, than the background of the box will change. For
> > this purpouse I need to find what is actually drawed on the canvas. Of
> > course I can store informations about all the object I've previously
> > written on the canvas, than pass these informations to the second part
> > of my program but I'm not sure if it's the best solution... Any dea?
> >
> > Thank you!
> > Pier
> .......
> as explained earlier it's pretty hard for reportlab functions to determine what
> will actually show up on the canvas. It seems fairly obvious that the boxes you
> are drawing and the presence/absence of text are connected so wouldn't the best
> thing be to combine them at the point where your text is drawn.
>
> It doesn't follow that you have to draw the whole of the box at that point, but
> provided your coordinates are right the presence/absence of letters (or text)
> could be used to draw an additional coloured rectangle or change the fill of
> what you draw.
> --
> Robin Becker
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