java-gnome-developer

[Java-gnome-developer] Patch for Pixbuf

[Destrius <des...@th...>]

Greetings,

I have only been looking at Java-Gnome for about 2 weeks or so, so I
apologize if I make any obvious mistakes.

Anyway, I've made some modifications to the
src/java/org/gnu/gdk/Pixbuf.java file to add in support for creating
pixbufs from images, retrieving the width and height of the image, and a
simple scale function. Nothing really special, but I'll work on tackling
the rest of the functions if nobody else will; I have a need for them as
I'm working on a graphical application in Java-Gnome.

The diff is attached; apply to Pixbuf.java.

On a similar note, I've been going through some of the previous posts
regarding TreeView and the displaying of Pixbufs; I have the same problem,
and after going through the code I think its something to do with the
GValue used to store the Pixbuf's handle (pointer).

When running a simple program using ListStore to create a list of images, I
get these messages:

(java-gnome:9913): GLib-GObject-CRITICAL **: file gvaluetypes.c: line 803
(g_value_get_pointer): assertion `G_VALUE_HOLDS_POINTER (value)' failed

(java-gnome:9913): GLib-GObject-WARNING **: unable to set property `pixbuf'
of type `GdkPixbuf' from value of type `gpointer'

I can't really be sure, but my guess is that somewhere down the line the
pointers get messed up and so the original GdkPixbuf can no longer be
referenced. The main problem is that I haven't managed to pinpoint where
the second message is originating from.

It could just as well be a problem with my current configuration, as for
some reason Sun's java refuses to run java-gnome programs without crashing
everytime an event occurs. I'm using kaffe instead, and it runs
fine. Programs are still compiled using the Sun JDK (j2se1.4), and jikes
works as well.

I'd appreciate if anybody has working code that displays a set of pixbufs
in a list, something like a thumbnail browser. This functionality is
integral to the program I'm writing, so I really need to get it working,
even if it involves several hours of staring at the gtk+ sources. :P

-- 
Destrius
http://harmos.threeone.net

Re: [Java-gnome-developer] Patch for Pixbuf

[Mark H. <mh...@ca...>]

On Wed, 2003-01-29 at 16:38, Destrius wrote:
> Anyway, I've made some modifications to the
> src/java/org/gnu/gdk/Pixbuf.java file to add in support for creating
> pixbufs from images, retrieving the width and height of the image, and a
> simple scale function. Nothing really special, but I'll work on tackling
> the rest of the functions if nobody else will; I have a need for them as
> I'm working on a graphical application in Java-Gnome.
Excellent, thanks. Help is always appreciated. 

> The diff is attached; apply to Pixbuf.java.
looks fine.

> On a similar note, I've been going through some of the previous posts
> regarding TreeView and the displaying of Pixbufs; I have the same problem,
> and after going through the code I think its something to do with the
> GValue used to store the Pixbuf's handle (pointer).
> 
> When running a simple program using ListStore to create a list of images, I
> get these messages:
> 
> (java-gnome:9913): GLib-GObject-CRITICAL **: file gvaluetypes.c: line 803
> (g_value_get_pointer): assertion `G_VALUE_HOLDS_POINTER (value)' failed
> 
> (java-gnome:9913): GLib-GObject-WARNING **: unable to set property `pixbuf'
> of type `GdkPixbuf' from value of type `gpointer'
> 
> I can't really be sure, but my guess is that somewhere down the line the
> pointers get messed up and so the original GdkPixbuf can no longer be
> referenced. The main problem is that I haven't managed to pinpoint where
> the second message is originating from.
I'd like to look at this as I wrote the tree code, but have very little
time at the moment, so am probably not going to be able to. If you send
me the code you're using, I'll see if I can spot any obvious errors.

> It could just as well be a problem with my current configuration, as for
> some reason Sun's java refuses to run java-gnome programs without crashing
> everytime an event occurs. I'm using kaffe instead, and it runs
> fine. Programs are still compiled using the Sun JDK (j2se1.4), and jikes
> works as well.
That happens for me too, but not for any of the other java-gnome
developers. I'm glad to have finally found someone else with the same
problem :)
I really have no idea why it happens.

-- 
  .''`. Mark Howard
 : :' :
 `. `'  http://www.tildemh.com 
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