initial commit

LibTSM/Util/FSMClasses/State.lua

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+-- ------------------------------------------------------------------------------ --
+--                                TradeSkillMaster                                --
+--                          https://tradeskillmaster.com                          --
+--    All Rights Reserved - Detailed license information included with addon.     --
+-- ------------------------------------------------------------------------------ --
+
+--- FSMState Class.
+-- This class represents a single state within an @{FSMMachine}.
+-- @classmod FSMState
+
+local _, TSM = ...
+local State = TSM.Init("Util.FSMClasses.State")
+local LibTSMClass = TSM.Include("LibTSMClass")
+local TempTable = TSM.Include("Util.TempTable")
+local FSMState = LibTSMClass.DefineClass("FSMState")
+local private = {
+	eventTransitionHandlerCache = {},
+}
+
+
+
+-- ============================================================================
+-- Class Meta Methods
+-- ============================================================================
+
+function State.Create(name)
+	return FSMState(name)
+end
+
+function State.IsInstance(obj)
+	return obj:__isa(FSMState)
+end
+
+
+
+-- ============================================================================
+-- Class Meta Methods
+-- ============================================================================
+
+function FSMState.__init(self, name)
+	self._name = name
+	self._onEnterHandler = nil
+	self._onExitHandler = nil
+	self._transitionValid = {}
+	self._events = {}
+end
+
+
+
+-- ============================================================================
+-- Public Class Methods
+-- ============================================================================
+
+--- Set the OnEnter handler.
+-- This function is called upon entering the state.
+-- @tparam FSMState self The FSM state object
+-- @tparam ?function|string handler The handler function or a method name to call on the context object
+-- @treturn FSMState The FSM state object
+function FSMState.SetOnEnter(self, handler)
+	assert(type(handler) == "function" or type(handler) == "string")
+	self._onEnterHandler = handler
+	return self
+end
+
+--- Set the OnExit handler.
+-- This function is called upon existing the state.
+-- @tparam FSMState self The FSM state object
+-- @tparam ?function|string handler The handler function or a method name to call on the context object
+-- @treturn FSMState The FSM state object
+function FSMState.SetOnExit(self, handler)
+	assert(type(handler) == "function" or type(handler) == "string")
+	self._onExitHandler = handler
+	return self
+end
+
+--- Add a transition.
+-- @tparam FSMState self The FSM state object
+-- @tparam string toState The state this transition goes to
+-- @treturn FSMState The FSM state object
+function FSMState.AddTransition(self, toState)
+	assert(not self._transitionValid[toState], "transition already exists")
+	self._transitionValid[toState] = true
+	return self
+end
+
+--- Add a handled event.
+-- @tparam FSMState self The FSM state object
+-- @tparam string event The name of the event
+-- @tparam function handler The function called when the event occurs
+-- @treturn FSMState The FSM state object
+function FSMState.AddEvent(self, event, handler)
+	assert(not self._events[event], "event already exists")
+	self._events[event] = handler
+	return self
+end
+
+--- Add a simple event-based transition.
+-- @tparam FSMState self The FSM state object
+-- @tparam string event The event name
+-- @tparam string toState The state to transition to
+-- @treturn FSMState The FSM state object
+function FSMState.AddEventTransition(self, event, toState)
+	if not private.eventTransitionHandlerCache[toState] then
+		private.eventTransitionHandlerCache[toState] = function(context, ...)
+			return toState, ...
+		end
+	end
+	return self:AddEvent(event, private.eventTransitionHandlerCache[toState])
+end
+
+
+
+-- ============================================================================
+-- Private Class Methods
+-- ============================================================================
+
+function FSMState._GetName(self)
+	return self._name
+end
+
+function FSMState._ToStateIterator(self)
+	local temp = TempTable.Acquire()
+	for toState in pairs(self._transitionValid) do
+		tinsert(temp, toState)
+	end
+	return TempTable.Iterator(temp)
+end
+
+function FSMState._IsTransitionValid(self, toState)
+	return self._transitionValid[toState]
+end
+
+function FSMState._HasEventHandler(self, event)
+	return self._events[event] and true or false
+end
+
+function FSMState._ProcessEvent(self, event, context, ...)
+	return self:_HandlerHelper(self._events[event], context, ...)
+end
+
+function FSMState._Enter(self, context, ...)
+	return self:_HandlerHelper(self._onEnterHandler, context, ...)
+end
+
+function FSMState._Exit(self, context)
+	return self:_HandlerHelper(self._onExitHandler, context)
+end
+
+function FSMState._HandlerHelper(self, handler, context, ...)
+	if type(handler) == "function" then
+		return handler(context, ...)
+	elseif type(handler) == "string" then
+		return context[handler](context, ...)
+	elseif handler ~= nil then
+		error("Invalid handler: "..tostring(handler))
+	end
+end