from retail

WeakAuras/SubscribableObject.lua

@@ -0,0 +1,74 @@
+if not WeakAuras.IsLibsOK() then return end
+local AddonName, Private = ...
+
+local WeakAuras = WeakAuras
+local L = WeakAuras.L
+
+local SubscribableObject =
+{
+  ClearSubscribers = function(self)
+    self.events = {}
+  end,
+
+  ClearCallbacks = function(self)
+    self.callbacks = {}
+  end,
+
+  AddSubscriber = function(self, event, subscriber, highPriority)
+    if not subscriber[event] then
+      print("Can't register for ", event, " ", subscriber, subscriber.type)
+      return
+    end
+
+    self.events[event] = self.events[event] or {}
+    local pos = highPriority and 1 or (#self.events[event] + 1)
+    if TableHasAnyEntries(self.events[event]) then
+      tinsert(self.events[event], pos, subscriber)
+    else
+      tinsert(self.events[event], pos, subscriber)
+      if self.callbacks[event] then
+        self.callbacks[event]()
+      end
+    end
+  end,
+
+  RemoveSubscriber = function(self, event, subscriber)
+    if self.events[event] then
+      local index = tIndexOf(self.events[event], subscriber)
+      if index then
+        tremove(self.events[event], index)
+        if not TableHasAnyEntries(self.events[event]) then
+          if self.callbacks[event] then
+            self.callbacks[event]()
+          end
+        end
+      end
+    end
+  end,
+
+  SetOnSubscriptionStatusChanged = function(self, event, cb)
+    self.callbacks[event] = cb
+  end,
+
+  Notify = function(self, event, ...)
+    if self.events[event] then
+      for _, subscriber in ipairs(self.events[event]) do
+        subscriber[event](subscriber, ...)
+      end
+    end
+  end,
+
+  HasSubscribers = function(self, event)
+    return self.events[event] and TableHasAnyEntries(self.events[event])
+  end
+}
+
+function Private.CreateSubscribableObject()
+  local system = {}
+  for f, func in pairs(SubscribableObject) do
+    system[f] = func
+    system.events = {}
+    system.callbacks = {}
+  end
+  return system
+end