/** * @file llstatemachine.h * @brief LLStateMachine class header file. * * $LicenseInfo:firstyear=2001&license=viewerlgpl$ * Second Life Viewer Source Code * Copyright (C) 2010, Linden Research, Inc. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; * version 2.1 of the License only. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA * * Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA * $/LicenseInfo$ */ #ifndef LL_LLSTATEMACHINE_H #define LL_LLSTATEMACHINE_H #include <string> #include "llerror.h" #include <map> class LLUniqueID { friend bool operator==(const LLUniqueID &a, const LLUniqueID &b); friend bool operator!=(const LLUniqueID &a, const LLUniqueID &b); protected: static U32 sNextID; U32 mId; public: LLUniqueID(){mId = sNextID++;} virtual ~LLUniqueID(){} U32 getID() {return mId;} }; class LLFSMTransition : public LLUniqueID { public: LLFSMTransition() : LLUniqueID(){}; virtual std::string getName()const { return "unnamed"; } }; class LLFSMState : public LLUniqueID { public: LLFSMState() : LLUniqueID(){}; virtual void onEntry(void *){}; virtual void onExit(void *){}; virtual void execute(void *){}; virtual std::string getName() const { return "unnamed"; } }; class LLStateDiagram { typedef std::map<LLFSMTransition*, LLFSMState*> Transitions; friend std::ostream& operator<<(std::ostream &s, LLStateDiagram &FSM); friend class LLStateMachine; protected: typedef std::map<LLFSMState*, Transitions> StateMap; StateMap mStates; Transitions mDefaultTransitions; LLFSMState* mDefaultState; BOOL mUseDefaultState; public: LLStateDiagram(); virtual ~LLStateDiagram(); protected: // add a state to the state graph, executed implicitly when adding transitions BOOL addState(LLFSMState *state); // add a directed transition between 2 states BOOL addTransition(LLFSMState& start_state, LLFSMState& end_state, LLFSMTransition& transition); // add an undirected transition between 2 states BOOL addUndirectedTransition(LLFSMState& start_state, LLFSMState& end_state, LLFSMTransition& transition); // add a transition that is taken if none other exist void addDefaultTransition(LLFSMState& end_state, LLFSMTransition& transition); // process a possible transition, and get the resulting state LLFSMState* processTransition(LLFSMState& start_state, LLFSMTransition& transition); // add a transition that exists for every state void setDefaultState(LLFSMState& default_state); // return total number of states with no outgoing transitions S32 numDeadendStates(); // does this state exist in the state diagram? BOOL stateIsValid(LLFSMState& state); // get a state pointer by ID LLFSMState* getState(U32 state_id); public: // save the graph in a DOT file for rendering and visualization BOOL saveDotFile(const std::string& filename); }; class LLStateMachine { protected: LLFSMState* mCurrentState; LLFSMState* mLastState; LLFSMTransition* mLastTransition; LLStateDiagram* mStateDiagram; public: LLStateMachine(); virtual ~LLStateMachine(); // set state diagram void setStateDiagram(LLStateDiagram* diagram); // process this transition void processTransition(LLFSMTransition &transition, void* user_data); // returns current state LLFSMState* getCurrentState() const; // execute current state void runCurrentState(void *data); // set state by state pointer BOOL setCurrentState(LLFSMState *initial_state, void* user_data, BOOL skip_entry = TRUE); // set state by unique ID BOOL setCurrentState(U32 state_id, void* user_data, BOOL skip_entry = TRUE); }; #endif //_LL_LLSTATEMACHINE_H