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, 44 insertions, 39 deletions

diff --git a/src/game-server/monster.cpp b/src/game-server/monster.cpp
index cdfe063a..330e3f4f 100644
--- a/src/game-server/monster.cpp
+++ b/src/game-server/monster.cpp
@@ -35,18 +35,6 @@
 
 #include <cmath>
 
-struct MonsterTargetEventDispatch: EventDispatch
-{
-    MonsterTargetEventDispatch()
-    {
-        typedef EventListenerFactory<Monster, &Monster::mTargetListener> Factory;
-        removed = &Factory::create< Entity, &Monster::forgetTarget >::function;
-        died = &Factory::create<Entity, &Monster::forgetTarget, Being>::function;
-    }
-};
-
-static MonsterTargetEventDispatch monsterTargetEventDispatch;
-
 MonsterClass::~MonsterClass()
 {
     for (std::vector<AttackInfo *>::iterator it = mAttacks.begin(),
@@ -67,7 +55,6 @@ double MonsterClass::getVulnerability(Element element) const
 Monster::Monster(MonsterClass *specy):
     Being(OBJECT_MONSTER),
     mSpecy(specy),
-    mTargetListener(&monsterTargetEventDispatch),
     mOwner(NULL)
 {
     LOG_DEBUG("Monster spawned! (id: " << mSpecy->getId() << ").");
@@ -137,12 +124,6 @@ Monster::Monster(MonsterClass *specy):
 
 Monster::~Monster()
 {
-    // Remove death listeners.
-    for (std::map<Being *, int>::iterator i = mAnger.begin(),
-         i_end = mAnger.end(); i != i_end; ++i)
-    {
-        i->first->removeListener(&mTargetListener);
-    }
 }
 
 void Monster::update()
@@ -229,11 +210,11 @@ void Monster::refreshTarget()
 
         // Determine how much we hate the target
         int targetPriority = 0;
-        std::map<Being *, int, std::greater<Being *> >::iterator angerIterator;
-        angerIterator = mAnger.find(target);
+        std::map<Being *, AggressionInfo>::iterator angerIterator = mAnger.find(target);
         if (angerIterator != mAnger.end())
         {
-            targetPriority = angerIterator->second;
+            const AggressionInfo &aggressionInfo = angerIterator->second;
+            targetPriority = aggressionInfo.anger;
         }
         else if (mSpecy->isAggressive())
         {
@@ -359,11 +340,15 @@ int Monster::calculatePositionPriority(Point position, int targetPriority)
     }
 }
 
-void Monster::forgetTarget(Entity *t)
+void Monster::forgetTarget(Entity *entity)
 {
-    Being *b = static_cast< Being * >(t);
+    Being *b = static_cast< Being * >(entity);
+    {
+        AggressionInfo &aggressionInfo = mAnger[b];
+        aggressionInfo.removedConnection.disconnect();
+        aggressionInfo.diedConnection.disconnect();
+    }
     mAnger.erase(b);
-    b->removeListener(&mTargetListener);
 
     if (b->getType() == OBJECT_CHARACTER)
     {
@@ -375,20 +360,42 @@ void Monster::forgetTarget(Entity *t)
 
 void Monster::changeAnger(Actor *target, int amount)
 {
-    if (target && (target->getType() == OBJECT_MONSTER
-        || target->getType() == OBJECT_CHARACTER))
+    const EntityType type = target->getType();
+    if (type != OBJECT_MONSTER && type != OBJECT_CHARACTER)
+        return;
+
+    Being *being = static_cast< Being * >(target);
+
+    if (mAnger.find(being) != mAnger.end())
     {
-        Being *t = static_cast< Being * >(target);
-        if (mAnger.find(t) != mAnger.end())
-        {
-            mAnger[t] += amount;
-        }
-        else
-        {
-            mAnger[t] = amount;
-            t->addListener(&mTargetListener);
-        }
+        mAnger[being].anger += amount;
+    }
+    else
+    {
+        AggressionInfo &aggressionInfo = mAnger[being];
+        aggressionInfo.anger = amount;
+
+        // Forget target either when it's removed or died, whichever
+        // happens first.
+        aggressionInfo.removedConnection =
+                being->signal_removed.connect(sigc::mem_fun(this, &Monster::forgetTarget));
+        aggressionInfo.diedConnection =
+                being->signal_died.connect(sigc::mem_fun(this, &Monster::forgetTarget));
+    }
+}
+
+std::map<Being *, int> Monster::getAngerList() const
+{
+    std::map<Being *, int> result;
+    std::map<Being *, AggressionInfo>::const_iterator i, i_end;
+
+    for (i = mAnger.begin(), i_end = mAnger.end(); i != i_end; ++i)
+    {
+        const AggressionInfo &aggressionInfo = i->second;
+        result.insert(std::make_pair(i->first, aggressionInfo.anger));
     }
+
+    return result;
 }
 
 int Monster::damage(Actor *source, const Damage &damage)
@@ -399,9 +406,7 @@ int Monster::damage(Actor *source, const Damage &damage)
     newDamage.delta = newDamage.delta * factor;
     int HPLoss = Being::damage(source, newDamage);
     if (source)
-    {
         changeAnger(source, HPLoss);
-    }
 
     if (HPLoss && source && source->getType() == OBJECT_CHARACTER)
     {