Function-type templated CallbackRegistry

base/callback_registry.h

Index: base/callback_registry.h
diff --git a/base/callback_registry.h b/base/callback_registry.h
index fcacbf549f2a79412130e0b1d902715a9663cca0..b05da78615eea0346f90c18e0d8d44d85ceae7c8 100644
--- a/base/callback_registry.h
+++ b/base/callback_registry.h
@@ -1,3 +1,8 @@
+// This file was GENERATED by command:
+//     pump.py callback_registry.h.pump
+// DO NOT EDIT BY HAND!!!
+
+
 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
@@ -9,6 +14,7 @@
 
 #include "base/basictypes.h"
 #include "base/callback.h"
+#include "base/callback_internal.h"
 #include "base/compiler_specific.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
@@ -28,8 +34,8 @@
 //
 //   typedef base::Callback<void(const Foo&)> OnFooCallback;
 //
-//   scoped_ptr<base::CallbackRegistry<Foo>::Subscription> RegisterCallback(
-//       const OnFooCallback& cb) {
+//   scoped_ptr<base::CallbackRegistry<void(const Foo&)>::Subscription>

[jam, 2013/09/24 02:16:31]

curious: there's no way to replace the "void(const Foo&" here with
OnFooCallback?

[Cait (Slow), 2013/09/24 14:20:37]

I could typedef the signature instead of the callback, then define both  the cb
and the registry in terms of that:
typedef void (FooCallbackType)(const Foo&)

base::CallbackRegistry<FooCallbackType> ...
base::Callback<FooCallbackType> ...

I'm worried that the typedef of a f'n signature might just make things more
confusing though?

[jam, 2013/09/24 14:49:48]

I see, yeah I agree that doesn't look more readable. The more similar defining
these callbacks is to using Bind, the more familiar it'll be to developers, as
well as less confusing.

+//   RegisterCallback(const OnFooCallback& cb) {
 //     return callback_registry_.Add(cb);
 //   }
 //
@@ -38,7 +44,7 @@
 //      callback_registry_.Notify(foo);
 //   }
 //
-//   base::CallbackRegistry<Foo> callback_registry_;
+//   base::CallbackRegistry<void(const Foo&)> callback_registry_;
 // };
 //
 //
@@ -59,7 +65,8 @@
 //     // Do something.
 //   }
 //
-//   scoped_ptr<base::CallbackRegistry<Foo>::Subscription> foo_subscription_;
+//   scoped_ptr<base::CallbackRegistry<void(const Foo&)>::Subscription>
+//       foo_subscription_;
 // };
 
 namespace base {
@@ -173,37 +180,199 @@ class CallbackRegistryBase {
 
 }  // namespace internal
 
-template <typename Details>
-class CallbackRegistry
-    : public internal::CallbackRegistryBase<Callback<void(const Details&)> > {
+template <typename Sig> class CallbackRegistry;
+
+template <>
+class CallbackRegistry<void(void)>
+    : public internal::CallbackRegistryBase<Callback<void(void)> > {
  public:
+  typedef Callback<void(void)> CallbackType;
+
   CallbackRegistry() {}
 
-  // Execute all active callbacks with |details| parameter.
-  void Notify(const Details& details) {
-    typename internal::CallbackRegistryBase<
-        Callback<void(const Details&)> >::Iterator it = this->GetIterator();
-    Callback<void(const Details&)>* cb;
+  void Notify() {
+    typename internal::CallbackRegistryBase<CallbackType>::Iterator it =
+        this->GetIterator();
+    CallbackType* cb;
     while((cb = it.GetNext()) != NULL) {
-      cb->Run(details);
+      cb->Run();
     }
   }
 
-private:
+ private:
   DISALLOW_COPY_AND_ASSIGN(CallbackRegistry);
 };
 
-template <> class CallbackRegistry<void>
-    : public internal::CallbackRegistryBase<Closure> {
+template <typename A1>
+class CallbackRegistry<void(A1)>
+    : public internal::CallbackRegistryBase<
+          Callback<void(A1)> > {
  public:
+  typedef Callback<void(A1)> CallbackType;
+
   CallbackRegistry() {}
 
-  // Execute all active callbacks.
-  void Notify() {
-    Iterator it = this->GetIterator();
-    Closure* cb;
+  void Notify(typename internal::CallbackParamTraits<A1>::ForwardType a1) {
+    typename internal::CallbackRegistryBase<CallbackType>::Iterator it =
+        this->GetIterator();
+    CallbackType* cb;
     while((cb = it.GetNext()) != NULL) {
-      cb->Run();
+      cb->Run(a1);
+    }
+  }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(CallbackRegistry);
+};
+
+template <typename A1, typename A2>
+class CallbackRegistry<void(A1, A2)>
+    : public internal::CallbackRegistryBase<
+          Callback<void(A1, A2)> > {
+ public:
+  typedef Callback<void(A1, A2)> CallbackType;
+
+  CallbackRegistry() {}
+
+  void Notify(typename internal::CallbackParamTraits<A1>::ForwardType a1,
+              typename internal::CallbackParamTraits<A2>::ForwardType a2) {
+    typename internal::CallbackRegistryBase<CallbackType>::Iterator it =
+        this->GetIterator();
+    CallbackType* cb;
+    while((cb = it.GetNext()) != NULL) {
+      cb->Run(a1, a2);
+    }
+  }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(CallbackRegistry);
+};
+
+template <typename A1, typename A2, typename A3>
+class CallbackRegistry<void(A1, A2, A3)>
+    : public internal::CallbackRegistryBase<
+          Callback<void(A1, A2, A3)> > {
+ public:
+  typedef Callback<void(A1, A2, A3)> CallbackType;
+
+  CallbackRegistry() {}
+
+  void Notify(typename internal::CallbackParamTraits<A1>::ForwardType a1,
+              typename internal::CallbackParamTraits<A2>::ForwardType a2,
+              typename internal::CallbackParamTraits<A3>::ForwardType a3) {
+    typename internal::CallbackRegistryBase<CallbackType>::Iterator it =
+        this->GetIterator();
+    CallbackType* cb;
+    while((cb = it.GetNext()) != NULL) {
+      cb->Run(a1, a2, a3);
+    }
+  }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(CallbackRegistry);
+};
+
+template <typename A1, typename A2, typename A3, typename A4>
+class CallbackRegistry<void(A1, A2, A3, A4)>
+    : public internal::CallbackRegistryBase<
+          Callback<void(A1, A2, A3, A4)> > {
+ public:
+  typedef Callback<void(A1, A2, A3, A4)> CallbackType;
+
+  CallbackRegistry() {}
+
+  void Notify(typename internal::CallbackParamTraits<A1>::ForwardType a1,
+              typename internal::CallbackParamTraits<A2>::ForwardType a2,
+              typename internal::CallbackParamTraits<A3>::ForwardType a3,
+              typename internal::CallbackParamTraits<A4>::ForwardType a4) {
+    typename internal::CallbackRegistryBase<CallbackType>::Iterator it =
+        this->GetIterator();
+    CallbackType* cb;
+    while((cb = it.GetNext()) != NULL) {
+      cb->Run(a1, a2, a3, a4);
+    }
+  }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(CallbackRegistry);
+};
+
+template <typename A1, typename A2, typename A3, typename A4, typename A5>
+class CallbackRegistry<void(A1, A2, A3, A4, A5)>
+    : public internal::CallbackRegistryBase<
+          Callback<void(A1, A2, A3, A4, A5)> > {
+ public:
+  typedef Callback<void(A1, A2, A3, A4, A5)> CallbackType;
+
+  CallbackRegistry() {}
+
+  void Notify(typename internal::CallbackParamTraits<A1>::ForwardType a1,
+              typename internal::CallbackParamTraits<A2>::ForwardType a2,
+              typename internal::CallbackParamTraits<A3>::ForwardType a3,
+              typename internal::CallbackParamTraits<A4>::ForwardType a4,
+              typename internal::CallbackParamTraits<A5>::ForwardType a5) {
+    typename internal::CallbackRegistryBase<CallbackType>::Iterator it =
+        this->GetIterator();
+    CallbackType* cb;
+    while((cb = it.GetNext()) != NULL) {
+      cb->Run(a1, a2, a3, a4, a5);
+    }
+  }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(CallbackRegistry);
+};
+
+template <typename A1, typename A2, typename A3, typename A4, typename A5,
+    typename A6>
+class CallbackRegistry<void(A1, A2, A3, A4, A5, A6)>
+    : public internal::CallbackRegistryBase<
+          Callback<void(A1, A2, A3, A4, A5, A6)> > {
+ public:
+  typedef Callback<void(A1, A2, A3, A4, A5, A6)> CallbackType;
+
+  CallbackRegistry() {}
+
+  void Notify(typename internal::CallbackParamTraits<A1>::ForwardType a1,
+              typename internal::CallbackParamTraits<A2>::ForwardType a2,
+              typename internal::CallbackParamTraits<A3>::ForwardType a3,
+              typename internal::CallbackParamTraits<A4>::ForwardType a4,
+              typename internal::CallbackParamTraits<A5>::ForwardType a5,
+              typename internal::CallbackParamTraits<A6>::ForwardType a6) {
+    typename internal::CallbackRegistryBase<CallbackType>::Iterator it =
+        this->GetIterator();
+    CallbackType* cb;
+    while((cb = it.GetNext()) != NULL) {
+      cb->Run(a1, a2, a3, a4, a5, a6);
+    }
+  }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(CallbackRegistry);
+};
+
+template <typename A1, typename A2, typename A3, typename A4, typename A5,
+    typename A6, typename A7>
+class CallbackRegistry<void(A1, A2, A3, A4, A5, A6, A7)>
+    : public internal::CallbackRegistryBase<
+          Callback<void(A1, A2, A3, A4, A5, A6, A7)> > {
+ public:
+  typedef Callback<void(A1, A2, A3, A4, A5, A6, A7)> CallbackType;
+
+  CallbackRegistry() {}
+
+  void Notify(typename internal::CallbackParamTraits<A1>::ForwardType a1,
+              typename internal::CallbackParamTraits<A2>::ForwardType a2,
+              typename internal::CallbackParamTraits<A3>::ForwardType a3,
+              typename internal::CallbackParamTraits<A4>::ForwardType a4,
+              typename internal::CallbackParamTraits<A5>::ForwardType a5,
+              typename internal::CallbackParamTraits<A6>::ForwardType a6,
+              typename internal::CallbackParamTraits<A7>::ForwardType a7) {
+    typename internal::CallbackRegistryBase<CallbackType>::Iterator it =
+        this->GetIterator();
+    CallbackType* cb;
+    while((cb = it.GetNext()) != NULL) {
+      cb->Run(a1, a2, a3, a4, a5, a6, a7);
     }
   }
 
@@ -213,4 +382,4 @@ template <> class CallbackRegistry<void>
 
 }  // namespace base
 
-#endif  // BASE_CALLBACK_REGISTRY_H_
+#endif  // BASE_CALLBACK_REGISTRY_H