DWT event handling

[BLS]

Frank Benoit schrieb:
> I added the template function Bill suggested once to the 
> dwt.widgets.Listener module.
> 
> http://www.dsource.org/projects/dwt-linux/browser/dwt/widgets/Listener.d?rev=243%3A84629474b5ec 
> 
> 
> You can see that in action in this snippet
> http://www.dsource.org/projects/dwt-samples/browser/snippets/treeeditor/Snippet111.d?rev=85%3Afa286c85e7b8 
> 
> 
> See lines: 102..106
> 
> Thanks Bill for the snippets and for this cool template function 
> suggestion.
> 
> Frank

Hi Frank, thanks for the update !

I still try to figure out how this code could fit ...

template MessageMap(Mappings ...) {
   void addListener(uint uID) {
      foreach(mapping; Mappings) {
        if(mapping.matches(uID)) // DWTxxxx
          mapping.executeAction();
      }
   }
}

//maybe we need template specialisation here ???


struct OnClose(alias fn) {
   alias fn executeAction;
   static bool matches(uint uid) { return uid == 5; }
}

struct OnRange(uint a, uint b, alias fn) {
   alias fn executeAction;
   static bool matches(uint uid) { return uid >= a && uid <= b; }
}


class Foo {
   void foo() {
     writefln("foo called");
   }
   void bar() {
     writefln("bar called");
   }

   mixin MessageMap!(
     OnClose!(foo),
     OnRange!(1, 3, bar)
   );

}

void main() {
   auto f = new Foo;
   f.addListener(5);
   f.addListener(2);
}

At least it looks simpler (to me) Ideas ? Bjoern