change effects animation calculation

modules/core/dispatcher.lua

@@ -8,33 +8,36 @@ function scheduleEvent(func, delay)
   eventId = eventId + 1
   local id = eventId
   local function proxyFunc()
-      if eventsTable[id] then
-        func()
-        eventsTable[id] = nil
-      end
+    if eventsTable[id] then
+      func()
+      eventsTable[id] = nil
+    end
   end
   eventsTable[id] = proxyFunc
   orig.scheduleEvent(proxyFunc, delay)
   return id
 end
 
+-- FIXME: the event function can be collected
+-- and the dispatcher would call an invalid function, generating an warning
 function removeEvent(id)
   if id and eventsTable[id] then
     eventsTable[id] = nil
+    return true
   end
 end
 
 -- fix original addEvent
 function addEvent(func)
-    eventId = eventId + 1
-    local id = eventId
-    local function proxyFunc()
-        if eventsTable[id] then
-          func()
-          eventsTable[id] = nil
-        end
+  eventId = eventId + 1
+  local id = eventId
+  local function proxyFunc()
+    if eventsTable[id] then
+      func()
+      eventsTable[id] = nil
     end
-    eventsTable[id] = proxyFunc
-    orig.addEvent(proxyFunc)
-    return id
+  end
+  eventsTable[id] = proxyFunc
+  orig.addEvent(proxyFunc)
+  return id
 end