Replaced EventListener with signals based on libsigc++

This replaces the rather hard to understand event dispatcher with a
probably even harder to understand templated library, but fortunately
we can rely on the available documentation.

Hopefully it will also help with the readability of our code and with
adding additional signals to other classes.

Added libsigc++ to README and Travis CI configuration.

Reviewed-by: Erik Schilling

1 files changed, 40 insertions, 38 deletions

diff --git a/src/game-server/quest.cpp b/src/game-server/quest.cpp
index 4d659227..c28a4213 100644
--- a/src/game-server/quest.cpp
+++ b/src/game-server/quest.cpp
@@ -18,24 +18,27 @@
  *  along with The Mana Server.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include <cassert>
-#include <list>
-#include <map>
-#include <string>
-
 #include "game-server/quest.h"
 
 #include "game-server/accountconnection.h"
 #include "game-server/character.h"
-#include "game-server/eventlistener.h"
 #include "utils/logger.h"
 
+#include <cassert>
+#include <list>
+#include <map>
+#include <string>
+
+#include <sigc++/connection.h>
+
 typedef std::list< QuestCallback * > QuestCallbacks;
 typedef std::map< std::string, QuestCallbacks > PendingVariables;
 
 struct PendingQuest
 {
     Character *character;
+    sigc::connection removedConnection;
+    sigc::connection disconnectedConnection;
     PendingVariables variables;
 };
 
@@ -72,22 +75,6 @@ void setQuestVar(Character *ch, const std::string &name,
     accountHandler->updateCharacterVar(ch, name, value);
 }
 
-/**
- * Listener for deleting related quests when a character disappears.
- */
-struct QuestDeathListener: EventDispatch
-{
-    static void partialRemove(const EventListener *, Entity *);
-
-    static void fullRemove(const EventListener *, Character *);
-
-    QuestDeathListener()
-    {
-        removed = &partialRemove;
-        disconnected = &fullRemove;
-    }
-};
-
 void QuestRefCallback::triggerCallback(Character *ch,
                                        const std::string &value) const
 {
@@ -103,10 +90,7 @@ void QuestRefCallback::triggerCallback(Character *ch,
     s->execute();
 }
 
-static QuestDeathListener questDeathDummy;
-static EventListener questDeathListener(&questDeathDummy);
-
-void QuestDeathListener::partialRemove(const EventListener *, Entity *t)
+static void partialRemove(Entity *t)
 {
     int id = static_cast< Character * >(t)->getDatabaseID();
     PendingVariables &variables = pendingQuests[id].variables;
@@ -119,11 +103,18 @@ void QuestDeathListener::partialRemove(const EventListener *, Entity *t)
     // The listener is kept in case a fullRemove is needed later.
 }
 
-void QuestDeathListener::fullRemove(const EventListener *, Character *ch)
+static void fullRemove(Character *ch)
 {
-    ch->removeListener(&questDeathListener);
+    int id = ch->getDatabaseID();
+
+    {
+        PendingQuest &pendingQuest = pendingQuests[id];
+        pendingQuest.removedConnection.disconnect();
+        pendingQuest.disconnectedConnection.disconnect();
+    }
+
     // Remove anything related to this character.
-    pendingQuests.erase(ch->getDatabaseID());
+    pendingQuests.erase(id);
 }
 
 void recoverQuestVar(Character *ch, const std::string &name,
@@ -134,11 +125,19 @@ void recoverQuestVar(Character *ch, const std::string &name,
     PendingQuests::iterator i = pendingQuests.lower_bound(id);
     if (i == pendingQuests.end() || i->first != id)
     {
-        i = pendingQuests.insert(i, std::make_pair(id, PendingQuest()));
-        i->second.character = ch;
-        /* Register a listener, because we cannot afford to get invalid
-           pointers, when we finally recover the variable. */
-        ch->addListener(&questDeathListener);
+        PendingQuest pendingQuest;
+        pendingQuest.character = ch;
+
+        /* Connect to removed and disconnected signals, because we cannot
+         * afford to get invalid pointers, when we finally recover the
+         * variable.
+         */
+        pendingQuest.removedConnection =
+                ch->signal_removed.connect(sigc::ptr_fun(partialRemove));
+        pendingQuest.disconnectedConnection =
+                ch->signal_disconnected.connect(sigc::ptr_fun(fullRemove));
+
+        i = pendingQuests.insert(i, std::make_pair(id, pendingQuest));
     }
     i->second.variables[name].push_back(f);
     accountHandler->requestCharacterVar(ch, name);
@@ -149,12 +148,14 @@ void recoveredQuestVar(int id,
                        const std::string &value)
 {
     PendingQuests::iterator i = pendingQuests.find(id);
-    if (i == pendingQuests.end()) return;
+    if (i == pendingQuests.end())
+        return;
 
-    Character *ch = i->second.character;
-    ch->removeListener(&questDeathListener);
+    PendingQuest &pendingQuest = i->second;
+    pendingQuest.removedConnection.disconnect();
+    pendingQuest.disconnectedConnection.disconnect();
 
-    PendingVariables &variables = i->second.variables;
+    PendingVariables &variables = pendingQuest.variables;
     PendingVariables::iterator j = variables.find(name);
     if (j == variables.end())
     {
@@ -162,6 +163,7 @@ void recoveredQuestVar(int id,
         return;
     }
 
+    Character *ch = pendingQuest.character;
     ch->questCache[name] = value;
 
     // Call the registered callbacks.