[Mono-winforms-list] Forms Architecture

Nikolaus Heger nheger at gmail.com
Tue Mar 14 20:21:07 EST 2006

Hi Developers,

I would like to know what the current direction of the Forms  
implementation is and why the decision was made to go the way that  
it's going now. I am a full time Java Swing developer and looking to  
see if Mono/Windows.Forms could become a credible alternative. I  
would be thrilled if it did.

 From the Forms home page: "The current approach is to implement all  
controls fully in managed code, it uses an abstract theme interface  
to paint the widgets. The default theme interfaces renders the  
widgets using System.Drawing".

This sounds exactly like Swing to me. There are two crucial problems  
with this approach:

1 - It's slow or there is an enormous effort required to make it  
fast. Hand-drawing widgets is not as fast as letting the OS do it,  
Swing has struggled with that for years. As of today, Swing is pretty  
good on Windows, but still dead slow on other platforms. That's due  
to years and years of effort by Sun to make Swing fast on Windows  
which resulted in making most of it HW accelerated - on Windows.
Even using system libraries which of course run on the graphics card  
- this is a slow approach, and making it fast requires insane effort.

2 - It doesn't look native. No matter how good your themes are, you  
are forced to play catch-up with the latest OS release. The apps  
always look a little bit off. It's impossible to make an application  
that will look "right" on different versions of an OS, like look  
right on Windows XP _and_ Windows 2000. In Swing, I have to choose  
the XP or the 2000 look, and my app will be stuck with it and look  
out of place on the other platform.

This is even worse with older apps - the look does not automatically  
update with the OS like native apps do. I have some software written  
in JDK 1.3 and because of subtle incompatibilities between 1.3, 1.4  
and 1.5 I had to ship the app with the JVM. Realistically, this is  
the _only_ way to ship reliable Java apps. The idea was of course  
that the users always have the latest and greatest JVM is installed  
on the system and apps run on it happily, but that is not a realistic  
approach (think QA time and maintenance effort here). So my app ships  
with 1.3 and will look like Windows 2000 on Win XP. Lame.

There is also a solution to these problems: Use native widgets. AWT  
was a bust, but SWT works quite well and I use it everyday with  
Eclipse. Despite all the obstacles that have to be overcome using  
such an approach, I think it's the best way to do a cross platform  
GUI. If the OS handles the drawing of widgets, it gets you speed and  
perfect looks for free. Clearly, there are drawbacks, and clearly,  
the Forms team has decided that the drawbacks are severe...

I realize that I was not there for the initial discussion of this, so  
if anyone wants to either point me to an archive of discussions or  
explain why the current Swing-like approach was chosen as the way to  
go forward, please respond.

Best regards,

	Nikolaus Heger

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