1 /* 2 * Copyright (C) 2010 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #ifndef A_HIERARCHICAL_STATE_MACHINE_H_ 18 19 #define A_HIERARCHICAL_STATE_MACHINE_H_ 20 21 #include <media/stagefright/foundation/AHandler.h> 22 23 namespace android { 24 25 struct AState : public RefBase { 26 AState(const sp<AState> &parentState = NULL); 27 28 sp<AState> parentState(); 29 30 protected: 31 virtual ~AState(); 32 33 virtual void stateEntered(); 34 virtual void stateExited(); 35 36 virtual bool onMessageReceived(const sp<AMessage> &msg) = 0; 37 38 private: 39 friend struct AHierarchicalStateMachine; 40 41 sp<AState> mParentState; 42 43 DISALLOW_EVIL_CONSTRUCTORS(AState); 44 }; 45 46 struct AHierarchicalStateMachine : public AHandler { 47 AHierarchicalStateMachine(); 48 49 protected: 50 virtual ~AHierarchicalStateMachine(); 51 52 virtual void onMessageReceived(const sp<AMessage> &msg); 53 54 // Only to be called in response to a message. 55 void changeState(const sp<AState> &state); 56 57 private: 58 sp<AState> mState; 59 60 DISALLOW_EVIL_CONSTRUCTORS(AHierarchicalStateMachine); 61 }; 62 63 } // namespace android 64 65 #endif // A_HIERARCHICAL_STATE_MACHINE_H_ 66
