Re: Fun with arrows

[Cyrille Chepelov <cyrille chepelov org>]

Le Thu, Apr 04, 2002, à 06:03:39PM -0600, Lars Clausen a écrit:
> Following Cyrille's suggestion, I tried making a better arrow selection
> menu.  What I came up with can be seen at
> <URL:http://shasta.cs.uiuc.edu/~lrclause/Dia/newarrows.png>.  The reason
> I'm using 1-pixel lines is that with 2-pixel lines, the stem is off-center,
> and with 3-pixel lines, you can't tell the three circle-with-slash arrows
> from each other.  You'll notice that any defects in the arrow drawing is
> highly visible here (for instance the integral line obviously has a
> blanked-out area).  Hopefully that will force us to improve the arrows:)


Who hoooo !!  This looks excellent !

(yes, the integral arrow clearly needs to use you new end-point adjustement 
code)...

 
> Details: I made this by adding a new renderer, RenderPixmap.  It allows
> rendering directly onto a pixmap, with a 1-1 translation of sizes.  Thus I
> can use the arrow drawing code directly to draw these.  This shrinks the
> dia_arrow_preview_expose function from 404 lines to about 30.  I should be
> able to do the same for the arrowhead property widget, though that won't
> save code.  I shall also be adding tooltips, I think.

... won't save code, but will replace a textual representation with a
graphical one the user will instantly understand. Globally more consistent.

This is really cool.

> And finally, a debugging hint:  I got in the situation where I need to
> debug the drawing of a menu.  Now X (or Gtk or someone) doesn't allow you
> to change window while a menu window is open, so when gdb stopped while the
> arrow menu was up, I couldn't do anything... except change to the console.
> So, I run gdb in 'screen' instead, when I am stuck in a menu, I change to
> the console and go 'screen -d -r'.  Voila, gdb session in console.

Aaah, if only screen was actually compatible with azerty keyboards...
        
        -- Cyrille

-- 
Grumpf.