Changed lib layout once more

lib/instance.lua

@@ -0,0 +1,216 @@
+local PATH = (...):gsub('%.[^%.]+$', '')
+
+local Entity = require(PATH..".entity")
+local System = require(PATH..".system")
+local Type   = require(PATH..".type")
+local List   = require(PATH..".list")
+
+local Instance = {}
+Instance.__index = Instance
+
+--- Creates a new Instance.
+-- @return The new instance
+function Instance.new()
+   local instance = setmetatable({
+      entities     = List(),
+      systems      = List(),
+      events       = {},
+      removed      = {},
+
+      __isInstance = true,
+   }, Instance)
+
+   return instance
+end
+
+--- Adds an Entity to the Instance.
+-- @param e The Entity to add
+-- @return self
+function Instance:addEntity(e)
+   if not Type.isEntity(e) then
+      error("bad argument #1 to 'Instance:addEntity' (Entity expected, got "..type(e)..")", 2)
+   end
+
+   e.instances:add(self)
+   self.entities:add(e)
+   self:checkEntity(e)
+
+   return self
+end
+
+--- Checks an Entity against all the systems in the Instance.
+-- @param e The Entity to check
+-- @return self
+function Instance:checkEntity(e)
+   if not Type.isEntity(e) then
+      error("bad argument #1 to 'Instance:checkEntity' (Entity expected, got "..type(e)..")", 2)
+   end
+
+   for i = 1, self.systems.size do
+      self.systems:get(i):__check(e)
+   end
+
+   return self
+end
+
+--- Marks an Entity as removed from the Instance.
+-- @param e The Entity to mark
+-- @return self
+function Instance:removeEntity(e)
+   if not Type.isEntity(e) then
+      error("bad argument #1 to 'Instance:removeEntity' (Entity expected, got "..type(e)..")", 2)
+   end
+
+   self.removed[#self.removed + 1] = e
+
+   return self
+end
+
+--- Completely removes all marked Entities in the Instance.
+-- @return self
+function Instance:flush()
+   if #self.removed > 0 then
+      for i = 1, #self.removed do
+         local e = self.removed[i]
+
+         e.instances:remove(self)
+         self.entities:remove(e)
+
+         for i = 1, self.systems.size do
+            self.systems:get(i):__remove(e)
+         end
+      end
+
+      self.removed = {}
+   end
+
+   return self
+end
+
+--- Adds a System to the Instance.
+-- @param system The System to add
+-- @param eventName The Event to register to
+-- @param callback The function name to call. Defaults to eventName
+-- @param enabled If the system is enabled. Defaults to true
+-- @return self
+function Instance:addSystem(system, eventName, callback, enabled)
+   if not Type.isSystem(system) then
+      error("bad argument #1 to 'Instance:addSystem' (System expected, got "..type(system)..")", 2)
+   end
+
+   if system.__instance and system.__instance ~= self then
+      error("System already in instance '" ..tostring(system.__instance).."'")
+   end
+
+   if not self.systems:has(system) then
+      self.systems:add(system)
+      system.__instance = self
+   end
+
+   if eventName then
+      self.events[eventName] = self.events[eventName] or {}
+
+      local i = #self.events[eventName] + 1
+      self.events[eventName][i] = {
+         system   = system,
+         callback = callback or eventName,
+         enabled  = enabled == nil and true or enabled,
+      }
+   end
+
+   local e
+   for i = 1, self.entities.size do
+      e = self.entities:get(i)
+
+      self:checkEntity(e)
+   end
+
+   return self
+end
+
+--- Enables a System in the Instance.
+-- @param system The System to enable
+-- @param eventName The Event it was registered to
+-- @param callback The callback it was registered with. Defaults to eventName
+-- @return self
+function Instance:enableSystem(system, eventName, callback)
+   if not Type.isSystem(system) then
+      error("bad argument #1 to 'Instance:enableSystem' (System expected, got "..type(system)..")", 2)
+   end
+
+   return self:setSystem(system, eventName, callback, true)
+end
+
+--- Disables a System in the Instance.
+-- @param system The System to disable
+-- @param eventName The Event it was registered to
+-- @param callback The callback it was registered with. Defaults to eventName
+-- @return self
+function Instance:disableSystem(system, eventName, callback)
+   if not Type.isSystem(system) then
+      error("bad argument #1 to 'Instance:disableSystem' (System expected, got "..type(system)..")", 2)
+   end
+
+   return self:setSystem(system, eventName, callback, false)
+end
+
+--- Sets a System 'enable' in the Instance.
+-- @param system The System to set
+-- @param eventName The Event it was registered to
+-- @param callback The callback it was registered with. Defaults to eventName
+-- @param enable The state to set it to
+-- @return self
+function Instance:setSystem(system, eventName, callback, enable)
+   if not Type.isSystem(system) then
+      error("bad argument #1 to 'Instance:setSystem' (System expected, got "..type(system)..")", 2)
+   end
+
+   callback = callback or eventName
+
+   if callback then
+      local listeners = self.events[eventName]
+
+      if listeners then
+         for i = 1, #listeners do
+            local listener = listeners[i]
+
+            if listener.system == system and listener.callback == callback then
+               listener.enabled = enable
+               break
+            end
+         end
+      end
+   end
+
+   return self
+end
+
+--- Emits an Event in the Instance.
+-- @param eventName The Event that should be emitted
+-- @param ... Parameters passed to listeners
+-- @return self
+function Instance:emit(eventName, ...)
+   if not eventName or type(eventName) ~= "string" then
+      error("bad argument #1 to 'Instance:emit' (String expected, got "..type(eventName)..")")
+   end
+
+   self:flush()
+   
+   local listeners = self.events[eventName]
+
+   if listeners then
+      for i = 1, #listeners do
+         local listener = listeners[i]
+
+         if listener.enabled then
+            listener.system[listener.callback](listener.system, ...)
+         end
+      end
+   end
+
+   return self
+end
+
+return setmetatable(Instance, {
+   __call = function(_, ...) return Instance.new(...) end,
+})