On 28.12.2004 02:26:51 Peter B. West wrote:
> Did you find the reference to java.awt.graphicsenv in PJA?

Just downloaded PJA. There's no reference in PJA other than in the
javadocs for PJABufferedImage and PJAGraphicsEnvironment. Seems like the
developer has to make sure that the system property is set (as could be
expected). It's interesting to note that PJA subclasses
SunGraphicsEnvironment and not GraphicsEnvironment. Like this they are
dependent on Sun-private classes.

> >>What am I missing?
> > 
> > 
> > I don't know. What are you trying to do? Is this about changing font
> > support for the PDFGraphics2D? Knowing that I might have some better
> > ideas.
> I'm just trying to understand what I'm doing when I fiddle with GEnv and 
> GDev.  When I first looked at using Java2D methods for all rendering, I 
> concluded that the GraphicsEnvironment was "closed", because there 
> seemed to be no independent pathway to the creation of a modified 
> GraphicsEnvironment.  That's why I was so excited when SVGGraphics2D was 
> mentioned on fop-dev.  Looking at the implementation, though, I see that 
> the same problems exist.  I don't know quite how to express my disquiet 
> about this, but in PJA's terms, it amounts to the implicit dependency on 
> the underlying native graphics rendering.
> <q>
> java.awt.Graphics methods such as drawLine (), fillOval (), drawString 
> (),... are implemented in the default JVM with native graphical 
> functions (except in some cases for Java2D) : That means that drawLine 
> () finally calls a GDI system function on Windows or X11 function on a 
> X11/UNIX machine even if the drawing is done in an off-screen image 
> using the class java.awt.Image. This ensures the best performance for 
> drawing graphics with Java.
> </q>

I can see nothing disturbing in here. I still think there's no need to
replace the default GraphicsEnvironment because you would have to start
doing the same thing PJA has to do to support BufferedImage etc.

> > Maybe it also helps to look at PJA (http://www.eteks.com/pja/en/) to get
> > a better understanding of what is involved in the whole thing.
> I just took a glance at PJA.  I'll have a look at the 2D implementation 
> code. PJA seems to have gone right back to the root of 
> GraphicsEnvironment and built its own from scratch.

Except that they built upon Sun-private classes.

> However,
> <q>
> Starting with release J2SETM 5.0, AWT has been re-implemented on the 
> Solaris and Linux platforms. The new Toolkit implementation provides the 
> following advantages:
>      * Removes the dependency on Motif and Xt libraries.
>      * Interoperates better with other GUI Toolkits.
>      * Provides better performance and quality.
> </q>
> I'll ask eTeks what the implications of this are for PJA.

Jeremias Maerki

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