Changeset 9e776f

Timestamp:

Sep 1, 2011, 1:51:25 PM (14 years ago)

Author:

Frederik Heber <heber@…>

Children:

d45509

Parents:

74e0f7

Message:

Observable::signOn/Off functions are now on const instance possible.

• maps of Observable are static anyway.
• we need some const_casts as instances in maps (which we need as lookup key in sign on/off) are non-const.
• whether there are more or fewer observers does not impact on the constness of a class but only affects a mutable part.

Location:

src/Patterns

Files:

• Observer.cpp (modified) (5 diffs)
• Observer.hpp (modified) (3 diffs)

src/Patterns/Observer.cpp

@@ -211 +211 @@
  * \param priority number in [-20,20]
  */
-void Observable::signOn(Observer *target,int priority) {
+void Observable::signOn(Observer *target,int priority) const
+{
   ASSERT(priority>=-20 && priority<=+20, "Priority out of range [-20:+20] when signing on Observer");
 #ifdef LOG_OBSERVER
-  observerLog().addMessage() << "@@ Signing on " << observerLog().getName(target) << " to " << observerLog().getName(this) << endl;
+  observerLog().addMessage() << "@@ Signing on " << observerLog().getName(target) << " to " << observerLog().getName(const_cast<Observable *>(this)) << endl;
 #endif
   bool res = false;
-  callees_t &callees = callTable[this];
+  callees_t &callees = callTable[const_cast<Observable *>(this)];
 
   callees_t::iterator iter;
@@ -231 +232 @@
  * \param *target Observer
  */
-void Observable::signOff(Observer *target) {
-  ASSERT(callTable.count(this),"SignOff called for an Observable without Observers.");
-#ifdef LOG_OBSERVER
-  observerLog().addMessage() << "** Signing off " << observerLog().getName(target) << " from " << observerLog().getName(this) << endl;
-#endif
-  callees_t &callees = callTable[this];
+void Observable::signOff(Observer *target) const
+{
+  ASSERT(callTable.count(const_cast<Observable *>(this)),"SignOff called for an Observable without Observers.");
+#ifdef LOG_OBSERVER
+  observerLog().addMessage() << "** Signing off " << observerLog().getName(target) << " from " << observerLog().getName(const_cast<Observable *>(this)) << endl;
+#endif
+  callees_t &callees = callTable[const_cast<Observable *>(this)];
 
   callees_t::iterator iter;
@@ -249 +251 @@
   }
   if(callees.empty()){
-    callTable.erase(this);
-  }
-}
-
-void Observable::signOn(Observer *target, Notification_ptr notification){
+    callTable.erase(const_cast<Observable *>(this));
+  }
+}
+
+void Observable::signOn(Observer *target, Notification_ptr notification) const
+{
   ASSERT(notification->owner==this,
          "Trying to sign on for a notification that is not provided by this object");
@@ -260 +263 @@
 }
 
-void Observable::signOff(Observer *target, Notification_ptr notification){
+void Observable::signOff(Observer *target, Notification_ptr notification) const
+{
   ASSERT(notification->owner==this,
          "Trying to sign off from a notification that is not provided by this object");
@@ -267 +271 @@
 }
 
-bool Observable::isBlocked(){
-  return depth.count(this) > 0;
+bool Observable::isBlocked() const
+{
+  return depth.count(const_cast<Observable *>(this)) > 0;
 }
 

src/Patterns/Observer.hpp

@@ -122 +122 @@
    * ussually no need to order the update sequence.
    */
-  virtual void signOn(Observer *target, int priority=0);
+  virtual void signOn(Observer *target, int priority=0) const;
 
   /**
@@ -128 +128 @@
    * updates will be recieved from that observer.
    */
-  virtual void signOff(Observer *target);
+  virtual void signOff(Observer *target) const;
 
   /**
    * Sign on for specialized notifications
    */
-  virtual void signOn(Observer *target, Notification_ptr notification);
+  virtual void signOn(Observer *target, Notification_ptr notification) const;
 
   /**
    * Stop receiving a specialized notification
    */
-  virtual void signOff(Observer *target, Notification_ptr notification);
+  virtual void signOff(Observer *target, Notification_ptr notification) const;
 
   /**
@@ -144 +144 @@
    * Changes are in Progress, that are not yet published.
    */
-  virtual bool isBlocked();
+  virtual bool isBlocked() const;
 
   Notification_ptr getChannel(size_t no) const;