The Embedded Angle
by Miro Samek    


Listing 1
 1: class Bomb : public Fsm {
 2:    int myTimeout;            // extended state variable
 3: public:
 4:    Bomb() : Fsm((State)&Bomb::initial) {}       // ctor
 5:    void initial(Event const *e); // initial pseudostate
 6:    void setting(Event const *e);       // state handler
 7:    void timing(Event const *e);        // state handler
 8:    void blast(Event const *e);         // state handler
 9: };


Listing 2
 1: void Bomb::initial(Event const *e) {
 2:    myTimeout = 2;
 3:    initialTran((State)&Bomb::setting);         // initial transition
 4: }
 5: void Bomb::setting(Event const *e) {
 6:    switch (e->sig) {
 7:    case UP_SIG:
 8:       if (myTimeout < 10) {
 9:          ++myTimeout;
10:       }
11:       break;
12:    case DOWN_SIG:
13:       if (myTimeout > 1) {
14:          --myTimeout;
15:       }
16:       break;
17:    case ARM_SIG:
18:       tran((State)&Bomb::timing);
19:       break;
20:    }
21: }
22: void Bomb::timing(Event const *e) {
23:    switch (e->sig) {
24:    case ENTRY_SIG:
25:       SetTimer(locHwnd, 1, 1000, 0);  // start ticking every 1000 ms
26:       break;
27:    case TICK_SIG:
28:       if (myTimeout > 0) {
29:          --myTimeout;
30:       }
31:       else {                                      // timeout expired
32:          tran((State)&Bomb::blast);
33:       }
34:       break;
35:    case EXIT_SIG:
36:       KillTimer(locHwnd, 1);                 // don't leak the timer!
37:       break;
38:    }
39: }





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