[prev in list] [next in list] [prev in thread] [next in thread] 

List:       kde-java
Subject:    Re: [Kde-java] Javalib on Windows
From:       Richard Dale <Richard_Dale () tipitina ! demon ! co ! uk>
Date:       2001-08-22 11:46:04
[Download RAW message or body]

On Wed, 22 Aug 2001, jansdal@it.dk wrote:
> Hi Richard (and group),
> 
> I've checked out the Javalib from the kde cvs and managed 
> to compile it under Windows with success. There are 2 minor 
> problems but now I have a working ScribbleWindow and some 
> other small java-programs. 
> 
> I must say that I'm really impressed by the speed of these 
> java/Qt programs. This is the way GUI should have been 
> done instead of the memory hungry and slow Swing classes.
> 
> Just wait until the java world finds out that it's possible 
> to have a java program with tabs, tables, trees, splitters 
> and all the other widgets in less than ? Mb RAM, thats 
> speedy and starts up in a snap. I think we are talking big 
> headlines.
> 
> This could be the return of java programs on clients, and 
> a way to compete with the upcoming C# programs, where GUI
> programs isn't that slow because they use native widgets.
> And without sacrificing platform independance.
Thanks! 'World domination' talk always cheers me up :-)...

> The 2 problems I'm having are:
> 
> 1. The linker complains about some unresolved externals in 
> QPrintDialog. I haven't digged into this problem, but by 
> excluding the file from my project I'm able to produce a 
> QtJava.dll file (size 1.13 Mb).
I think QPrintDialog is missing from the free edition. 

> 2. When I run the ScribbleWindow program I get an 
> assertion:
> ASSERT: "src_dc && dst_dc" in C:\Home\andy\qt\2.3\src\
> kernel\qpaintdevice_win.cpp (311)
> I have no ideas what this problem is about since I don't 
> have the source code for qpaintdevice_win.cpp.
Eddie Chan has done the PC port - he hasn't had this problem I'll cc this mail
to him - perhaps you've built it with a different compiler.

> There are two drawbacks with this javalib. First, its 
> not compatible with Swing so existing Swing programs 
> can't easily be converted and second, the commercial 
> edition of Qt from TrollTech is very expensive. (I'm 
> using the freeware edition, because I cannot afford to 
> buy the commercial edition. This is something that I do 
> in my spare time.)
I think it would be easier to start again with a Swing ui, and hope the
backend of the app won't need changing too much. There is a patch for the uic
tool in the qtjava project, so you can use Qt designer to help layout the ui,
which should speed up redoing it.

If you use the free Qt LInux edition to develop your app, the same byte codes
in the .class files will run on a PC. I would say Qt is good value as a
commercial library for Windows.

> What I'm going to do now is write a demo program that 
> includes most of the widgets, to see the memory usage, 
> speed and startup time. 
Eddie has started writing an app 'QtSet', to do exactly this - he's keen to
find anyone to help out with it.

> Before I found out that you where writing this javalib, 
> I actually was trying to do the same. And I managed to
> implement some of the basic widgets. My wrappers did almost
> the exact same thing of yours, with the exception of how 
> the widgets were allocated. In my aproach each widget holds 
> a native handle to a C++ widget. If you are interested I 
> can sent you a copy of my work.
Each Qt Java class has an instance variable called '_qt', which holds the
native handle. I'd be interested to have a look at your work though - please
send it to me. I downloaded a GNOME project from Source Forge to wrap GTK for
java using JNI, but I couldn't really understand how it worked too well to get
any ideas from it.

> How are you going to tell the java world that you have 
> something unique. I hope that it's not going to live a 
> quiet life hidden deep down in the kde bindings. Not that 
> kde isn't a good thing, it definitely is, but a way to 
> convert all these windows users is to show them that the 
> programs that they use and like also run on linux. 
> Unmodified, just copy the jar file to the linux box and 
> off we go.
At this site on Source Forge, we're starting to gather men and materiel :-).
There is the dll for Windows, a Qt 3 version of the bindings in the cvs, and a
version of the javauic tool that is easier to build. We are currently starting
to sort out rpm's for LInux and so on. 

http://sourceforge.net/projects/qtjava/

So please contact Eddie if you'd like to join the project, more help would be
great.

Eddie Chan <eddie.chan@bigfoot.com>

-- Richard
_______________________________________________
Kde-java mailing list
Kde-java@mail.kde.org
http://mail.kde.org/mailman/listinfo/kde-java

[prev in list] [next in list] [prev in thread] [next in thread]