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feat(cmat): pass hints to Ex42 observers

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Extend the Ex42 observer pattern with Hint objects so each
observer receives the reason for the update instead of
querying the subject:

- Subject::notify() and Observer::update() now take a
  const Hint& argument.
- Add LightHint and WaitHint carrying the traffic light
  state and WAIT button state, defined in Pelican.h.
- Pole dispatches on hint type using dynamic_cast.
- The Pole constructor sets its initial lights directly
  from the Pelican's current state, since no notification
  is sent at startup. Stopgap until the initial update
  is handled properly.

Co-authored-by: Qwen 3.8 27B <qwen3.8_27b-q3_k_xl@lmstudio.local>
This commit is contained in:
portersky
2026-10-07 11:31:16 +02:00
co-authored by Qwen 3.8 27B
parent 11b96e4410
commit a65e84e796
7 changed files with 277 additions and 244 deletions
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cmat/Ex42/Pelican.h
+63 -51
View File
@@ -1,51 +1,63 @@
// ======================================================
//
// Represents a Pelican crossing
//
// ======================================================
#ifndef PELICAN_H
#define PELICAN_H
#include "Subject.h"
class PelicanTimer;
class Pelican : public Subject {
public:
Pelican();
// call when the WAIT button has been pressed
void press(void);
// states that a Pelican can be in
enum PelicanState { RED_STATE, YELLOW_FLASHING, GREEN_TIMING, GREEN_IDLE, YELLOW_STATE };
bool isPressed() const { return pressed; }
PelicanState getState() const { return state; }
private:
// state that this Pelican is in
PelicanState state;
// called by PelicanTimer when the lights need to change
void timerExpired(void);
const unsigned int RED_TIME;
const unsigned int YELLOW_TIME;
const unsigned int GREEN_TIME;
const unsigned int FLASH_TIME;
// indicates whether the WAIT light should be on
bool pressed;
// Timer that indicates when the lights should change
PelicanTimer *myTimer;
private:
// prevent general use of copy ctor and operator=
Pelican(const Pelican &);
Pelican &operator=(const Pelican &);
};
#endif
// ======================================================
//
// Represents a Pelican crossing
//
// ======================================================
#ifndef PELICAN_H
#define PELICAN_H
#include "Subject.h"
class PelicanTimer;
class Pelican : public Subject {
public:
Pelican();
// call when the WAIT button has been pressed
void press(void);
// states that a Pelican can be in
enum PelicanState { RED_STATE, YELLOW_FLASHING, GREEN_TIMING, GREEN_IDLE, YELLOW_STATE };
bool isPressed() const { return pressed; }
PelicanState getState() const { return state; }
private:
// state that this Pelican is in
PelicanState state;
// called by PelicanTimer when the lights need to change
void timerExpired(void);
const unsigned int RED_TIME;
const unsigned int YELLOW_TIME;
const unsigned int GREEN_TIME;
const unsigned int FLASH_TIME;
// indicates whether the WAIT light should be on
bool pressed;
// Timer that indicates when the lights should change
PelicanTimer *myTimer;
private:
// prevent general use of copy ctor and operator=
Pelican(const Pelican &);
Pelican &operator=(const Pelican &);
};
class LightHint : public Hint {
public:
LightHint(Pelican::PelicanState s) : state(s) { }
Pelican::PelicanState state;
};
class WaitHint : public Hint {
public:
WaitHint (bool p) : pressed(p) {}
bool pressed;
};
#endif