DWT event handling

[Bill Baxter]

BLS wrote:
> 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

I don't get it.  What's 5?

--bb