Extending Objective-C from D.

[Guillaume Piolat via Digitalmars-d]

On Saturday, 9 January 2016 at 10:09:12 UTC, Jeremie Pelletier 
wrote:
> Hello, I'm trying to see if I can write a full Cocoa app in D, 
> and I'm having trouble creating D classes when the underlying 
> Objective-C interfaces have methods.
>
> It works for the app delegate because it needs to override 
> them, but for other classes the compiler says the Objective-C 
> methods aren't implemented in the D subclass.
>

If you are looking to implement/override Obj-C methods in D, I 
have done it here deriving from NSView
https://github.com/p0nce/dplug/blob/master/window/dplug/window/cocoawindow.d#L426

Using the Obj-C runtime, the D object declares a new class 
object, populates it with methods (inverse mapping is done with 
an instance variable containing "this"). Ugly, but works.

Example of a method callback: 
https://github.com/p0nce/dplug/blob/master/window/dplug/window/cocoawindow.d#L499
Do not forget to prepend the callback arguments with id and 
selector.