Changeset b324a3 for src/CodePatterns/Observer

Timestamp:

Sep 5, 2013, 2:14:06 PM (12 years ago)

Author:

Frederik Heber <heber@…>

Children:

44f368

Parents:

37d941

git-author:

Frederik Heber <heber@…> (09/05/13 14:09:44)

git-committer:

Frederik Heber <heber@…> (09/05/13 14:14:06)

Message:

Added Graveyard for to-be-destroyed Observables.

• also added Zombie class that wraps an Observable.
• Notification and Observable have new function getNumberOfObservers().
• added unit test for Graveyard.

Location:

src/CodePatterns/Observer

Files:

• Graveyard.hpp (added)
• Notification.hpp (modified) (1 diff)
• Observable.hpp (modified) (4 diffs)
• Zombie.hpp (added)

src/CodePatterns/Observer/Notification.hpp

@@ -65 +65 @@
   void subjectKilled(Observable * const publisher);
 
+  /** Getter for the number of Observer for this notification (channel).
+   *
+   * \return number of added observers
+   */
+  size_t getNumberOfObservers() const
+  { return targets.size(); }
+
 private:
   typedef std::set<Observer*> targets_t;

src/CodePatterns/Observer/Observable.hpp

@@ -17 +17 @@
 #include <set>
 #include <string>
+#include <boost/function.hpp>
 
 #include "CodePatterns/Range.hpp"
 #include "CodePatterns/Observer/defs.hpp"
 #include "CodePatterns/Observer/Observer.hpp"
+
+class Graveyard;
 
 /**
@@ -34 +37 @@
  * we call Channels::subjectKilled() to let Observers that have only signed
  * on to single channel still know when their observable has died.
+ *
+ * Note that one may allow an Observable to live some over-time by using
+ * the Graveyard. This allows any Observer to still access the instance
+ * in order to properly sign off. It is destroyed when no Observer is left.
  */
 class Observable : public Observer {
@@ -93 +100 @@
   Notification_ptr getChannel(size_t no) const;
 
+  size_t getNumberOfObservers() const;
+
 protected:
   virtual void update(Observable *publisher);
@@ -126 +135 @@
   static std::set<Observable*> busyObservables;
 
+private:
+  friend class Zombie;
+  friend class Graveyard;
+
+  typedef boost::function<void (const Observable*)> graveyard_informer_t;
+
+  //!> bound function to call when Observer are signing off
+  graveyard_informer_t &graveyard_informer;
+
+  //!> default informer that does nothing
+  static graveyard_informer_t noop_informer;
+
+  /** Sets the bound function for over-time life-time management.
+   *
+   * \param _graveyard Graveyard to inform of leaving Observers
+   */
+  void setGraveyardInformer(graveyard_informer_t &_graveyard_informer)
+  {
+    graveyard_informer = _graveyard_informer;
+  }
+
   //! @cond
   // Structure for RAII-Style notification