[Kde-bindings] KDE/kdebindings

[Arno Rehn]

Am Montag 09 Juni 2008 20:49:25 schrieb Richard Dale:
> On Monday 09 June 2008 18:13:43 Arno Rehn wrote:
> > Am Montag 09 Juni 2008 15:28:21 schrieb Richard Dale:
> > > On Monday 09 June 2008 13:28:13 Arno Rehn wrote:
> > > > > The only thing I don't like is subclassing SmokeInvocation and
> > > > > giving it a different name in the generated code. That seems
> > > > > pointless and ugly to me any old static constructor will load the
> > > > > smoke lib. In the soprano bindings I had a source called
> > > > > 'Soprano.cs' with this:
> > > > >
> > > > > namespace Soprano {
> > > > >       using Qyoto;
> > > > >       using System;
> > > > >       using System.Runtime.InteropServices;
> > > > >
> > > > >       public class InitSoprano {
> > > > >               [DllImport("libsoprano-sharp", CharSet=CharSet.Ansi)]
> > > > >               static extern void Init_soprano();
> > > > >
> > > > >               static InitSoprano() {
> > > > >                       Init_soprano();
> > > > >               }
> > > > >       }
> > > > > }
> > > > >
> > > > > And just left SmokeInvocation as it was in the generated code. So I
> > > > > think we should have a Kimono.cs source with the same thing in it.
> > > >
> > > > My intention was to simplify the code for those who actually use the
> > > > C# bindings. And a static constructor is called when the class that
> > > > defines it is used for the first time. Since SmokeInvocation is
> > > > always used before any other thing, it makes sure that the smoke lib
> > > > is always loaded. If we put that code into another class that is
> > > > completely unrelated to the binding, we will always have to call
> > > > InitFoo() if we want to use it. So subclassing SmokeInvocation for
> > > > the different bindings seemed to be the best solution to me.
> > >
> > > OK, I understand the problem now, but I still think the solution of
> > > renaming SmokeInvocation is ugly. I found this after a bit of googling:
> > >
> > > "Note, however, that you *can* put code in your AppDomain to execute
> > > when *another* DLL loads. (The AppDomain.AssemblyLoad event.) That
> > > means you can write your code once, and so long as that event handler
> > > is added before the other assemblies are loaded, you can do all the
> > > appropriate things."
> > >
> > > http://osdir.com/ml/windows.devel.dotnet.cx/2004-01/msg00064.html
> > >
> > > So is the Qyoto dll in an AppDomain, or can we put it in one?
> >
> > Yes, of couse the Qyoto dll is always in an AppDomain. So we'd have to
> > define a standard class class name, whoch holds a method to do the
> > initialization. Whenever an assembly is loaded, we have to look for that
> > class via reflection and call the initialization method.
>
> I've read a bit more about this, and it seems quite straightforward to
> implement - you just set up a static delegate that receives the dll loaded
> event and then do what you say. So I would prefer doing it this way - an
> app domain called 'Qyoto' and an initialize class called InitSmoke in each
> dll for instance.
Ok, I just tested this and it doesn't quite work out. Consider this:

using System;
using Qyoto;

class MainClass {
	public static void AssemblyLoad(object sender, AssemblyLoadEventArgs args) {
		Console.WriteLine(args.LoadedAssembly.FullName);
	}
	
	public static void Main(string[] args) {
		AppDomain.CurrentDomain.AssemblyLoad += AssemblyLoad;
// 		System.Reflection.Assembly.Load("qt-dotnet, Version=4.4.0.0, 
Culture=neutral, PublicKeyToken=194a23ba31c08164");
	}
}

This will do nothing, since we add the event handler _after_ the assembly is 
loaded. The same will happen if we define such an event handler in the Qyoto 
runtime. If we load the assembly dynamically, it will work well. So going via 
AppDomain.AssemblyLoad is not really an option, I think.

-- 
Arno Rehn
arno at arnorehn.de