modules/gui/skins2/utils/fsm.cpp

   1 /*****************************************************************************
   2  * fsm.cpp
   3  *****************************************************************************
   4  * Copyright (C) 2003 the VideoLAN team
   5  * $Id$
   6  *
   7  * Authors: Cyril Deguet     <asmax@via.ecp.fr>
   8  *          Olivier Teulière <ipkiss@via.ecp.fr>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  23  *****************************************************************************/
  24
  25 #include "fsm.hpp"
  26 #include "../commands/cmd_generic.hpp"
  27
  28
  29 void FSM::addState( const string &state )
  30 {
  31     m_states.insert( state );
  32 }
  33
  34
  35 void FSM::addTransition( const string &state1, const string &event,
  36                          const string &state2, CmdGeneric *pCmd )
  37 {
  38     // Check that we already know the states
  39     if( m_states.find( state1 ) == m_states.end() ||
  40         m_states.find( state2 ) == m_states.end() )
  41     {
  42         msg_Warn( getIntf(),
  43                   "FSM: ignoring transition between invalid states" );
  44         return;
  45     }
  46
  47     Key_t key( state1, event );
  48     Data_t data( state2, pCmd );
  49
  50     // Check that the transition doesn't already exist
  51     if( m_transitions.find( key ) != m_transitions.end() )
  52     {
  53         msg_Warn( getIntf(), "FSM: transition already exists" );
  54         return;
  55     }
  56
  57     m_transitions[key] = data;
  58 }
  59
  60
  61 void FSM::setState( const string &state )
  62 {
  63     if( m_states.find( state ) == m_states.end() )
  64     {
  65         msg_Warn( getIntf(), "FSM: trying to set an invalid state" );
  66         return;
  67     }
  68     m_currentState = state;
  69 }
  70
  71
  72 void FSM::handleTransition( const string &event )
  73 {
  74     string tmpEvent = event;
  75     Key_t key( m_currentState, event );
  76     map<Key_t, Data_t>::const_iterator it;
  77
  78     // Find a transition
  79     it = m_transitions.find( key );
  80
  81     // While the matching fails, try to match a more generic transition
  82     // For example, if "key:up:F" isn't a transition, "key:up" or "key" may be
  83     while( it == m_transitions.end() &&
  84            tmpEvent.rfind( ":", tmpEvent.size() ) != string::npos )
  85     {
  86         // Cut the last part
  87         tmpEvent = tmpEvent.substr( 0, tmpEvent.rfind( ":", tmpEvent.size() ) );
  88
  89         key.second = tmpEvent;
  90         it = m_transitions.find( key );
  91     }
  92
  93     // No transition was found
  94     if( it == m_transitions.end() )
  95     {
  96         return;
  97     }
  98
  99     // Change state
 100     m_currentState = (*it).second.first;
 101
 102     // Call the callback, if any
 103     CmdGeneric *pCmd = (*it).second.second;
 104     if( pCmd != NULL )
 105     {
 106         pCmd->execute();
 107     }
 108 }