connection: Use weak_raw_ptr for slot_base.

murraycu · murraycu · commit 846d1fe14af2 · 2016-05-02T10:19:54.000+02:00
Instead of connection deriving from notifiable and setting/unsetting
its own notification callbacks. This simplifies the code.
diff --git a/sigc++/connection.cc b/sigc++/connection.cc
@@ -29,16 +29,11 @@ connection::connection() noexcept : slot_(nullptr)
 connection::connection(slot_base& slot)
 : slot_(&slot)
 {
-  if (slot_)
-    slot_->add_destroy_notify_callback(this, &notify_slot_invalidated);
 }
 
 
 connection::connection(const connection& c) : slot_(c.slot_)
 {
-  // Let the connection forget about the signal handler when the handler object dies:
-  if (slot_)
-    slot_->add_destroy_notify_callback(this, &notify_slot_invalidated);
 }
 
 connection&
@@ -50,8 +45,6 @@ connection::operator=(const connection& src)
 
 connection::~connection()
 {
-  if (slot_)
-    slot_->remove_destroy_notify_callback(this);
 }
 
 bool
@@ -97,22 +90,10 @@ connection::operator bool() const noexcept
 }
 
 void
-connection::set_slot(slot_base* sl)
+connection::set_slot(const sigc::internal::weak_raw_ptr<slot_base>& sl)
 {
-  if (slot_)
-    slot_->remove_destroy_notify_callback(this);
-
   slot_ = sl;
-
-  if (slot_)
-    slot_->add_destroy_notify_callback(this, &notify_slot_invalidated);
 }
 
-void
-connection::notify_slot_invalidated(notifiable* data)
-{
-  auto self = static_cast<connection*>(data);
-  self->slot_ = nullptr;
-}
 
 } /* namespace sigc */
diff --git a/sigc++/connection.h b/sigc++/connection.h
@@ -20,6 +20,7 @@
 #define SIGC_CONNECTION_HPP
 #include <sigc++config.h>
 #include <sigc++/functors/slot_base.h>
+#include <sigc++/weak_raw_ptr.h>
 
 namespace sigc
 {
@@ -31,7 +32,7 @@ namespace sigc
  *
  * @ingroup signal
  */
-struct SIGC_API connection : public notifiable
+struct SIGC_API connection
 {
   /** Constructs an empty connection object. */
   connection() noexcept;
@@ -89,17 +90,12 @@ struct SIGC_API connection : public notifiable
   explicit operator bool() const noexcept;
 
 private:
-  void set_slot(slot_base* sl);
-
-  /** Callback that is executed when the referred slot is destroyed.
-   * @param data The connection object notified (@p this).
-   */
-  static void notify_slot_invalidated(notifiable* data);
+  void set_slot(const sigc::internal::weak_raw_ptr<slot_base>& sl);
 
   /* Referred slot. Set to zero from notify().
    * A value of zero indicates an "empty" connection.
    */
-  slot_base* slot_;
+  sigc::internal::weak_raw_ptr<slot_base> slot_;
 };
 
 } /* namespace sigc */

Original file line number	Diff line number	Diff line change
`@@ -29,16 +29,11 @@ connection::connection() noexcept : slot_(nullptr)`
`29`	`29`	`connection::connection(slot_base& slot)`
`30`	`30`	`: slot_(&slot)`
`31`	`31`	`{`
`32`		`- if (slot_)`
`33`		`- slot_->add_destroy_notify_callback(this, &notify_slot_invalidated);`
`34`	`32`	`}`
`35`	`33`
`36`	`34`
`37`	`35`	`connection::connection(const connection& c) : slot_(c.slot_)`
`38`	`36`	`{`
`39`		`- // Let the connection forget about the signal handler when the handler object dies:`
`40`		`- if (slot_)`
`41`		`- slot_->add_destroy_notify_callback(this, &notify_slot_invalidated);`
`42`	`37`	`}`
`43`	`38`
`44`	`39`	`connection&`
`@@ -50,8 +45,6 @@ connection::operator=(const connection& src)`
`50`	`45`
`51`	`46`	`connection::~connection()`
`52`	`47`	`{`
`53`		`- if (slot_)`
`54`		`- slot_->remove_destroy_notify_callback(this);`
`55`	`48`	`}`
`56`	`49`
`57`	`50`	`bool`
`@@ -97,22 +90,10 @@ connection::operator bool() const noexcept`
`97`	`90`	`}`
`98`	`91`
`99`	`92`	`void`
`100`		`-connection::set_slot(slot_base* sl)`
	`93`	`+connection::set_slot(const sigc::internal::weak_raw_ptr<slot_base>& sl)`
`101`	`94`	`{`
`102`		`- if (slot_)`
`103`		`- slot_->remove_destroy_notify_callback(this);`
`104`		`-`
`105`	`95`	`slot_ = sl;`
`106`		`-`
`107`		`- if (slot_)`
`108`		`- slot_->add_destroy_notify_callback(this, &notify_slot_invalidated);`
`109`	`96`	`}`
`110`	`97`
`111`		`-void`
`112`		`-connection::notify_slot_invalidated(notifiable* data)`
`113`		`-{`
`114`		`- auto self = static_cast<connection*>(data);`
`115`		`- self->slot_ = nullptr;`
`116`		`-}`
`117`	`98`
`118`	`99`	`} /* namespace sigc */`