Re: [Gcjwebplugin-devel] Kudos and some issues

[Thomas Fitzsimmons]

On Mon, 2005-05-23 at 13:07 +0200, Fridrich Strba wrote:
> Hello, after a success of gcj-4.0.x in openoffice.org, I was tempted to
> try to make the open implementation of Java the default java on my
> machines. I am playing since some weeks with gcjwebplugin, more exactly
> with gcjappletviewer.
> 
> I really like what I see. I tried many of the applets from
> http://math.hws.edu/javanotes/ (awt and swing) and
> http://math.hws.edu/eck/cs124/javanotes3/ (awt only)
> 
> I have some problems with the swing applets which is undertandable since
> the free swing implementation is not as mature as the open awt
> implementation. Nevertheless, I discovered an applet that has a very
> strange behaviour and I was just wondering whether someone is interested
> to check and try to understand the problem. Its source is to be found at
> http://math.hws.edu/eck/cs124/javanotes3/source/ColorChooserApplet.java

This applet exposed a long-standing bug in the GTK scrollbar peer.  The
fix depends on the GTK patch here:

http://bugzilla.gnome.org/show_bug.cgi?id=133263

which landed in GTK 2.6.  I've updated GNU Classpath's configure script
to require GTK 2.6 and I've committed the scrollbar peer patch.  Now
this applet works perfectly.

> The following applet (representative of quite a number applets) throws a
> java.lang.NullPointerException. Nevetheless, it is thrown only with
> native gcjappletviewer. If I use the script gcjappletviewer with gij as
> bytecode interpreter, the exception is thrown too. If I launch the
> script gcjappletviewer with Sun's Java 1.5.0_03, it works well.
> 
> The "trace" is:
> address@hidden java-examples]$ gcjappletviewer Mandelbrot.class
> raw arguments:
>   Mandelbrot.class
> parsed applet tags:
>   tag 0:
>    name=
>    code=Mandelbrot.class
>    codebase=
>    archive=[]
>    parameters={width=320, height=200}
>    documentbase=file:/home/fridrich/java-examples/
> 
> Exception during event dispatch:
> java.lang.NullPointerException
>     at Mandelbrot$Display.actionPerformed(java.awt.event.ActionEvent)
> (Unknown Source)

The action command of this action event was not being set to the name of
the button.  Fixing this doesn't make the applet work entirely though.
Neither the canvas nor the buttons are updated properly.  I'll report
these problems to Roman Kennke.

Tom