API: add C++ callback class for convenience

Author: Powerbyte7

examples/cpp/cp_app.cpp

@@ -50,13 +50,22 @@ static struct osdp_channel cp_channel = {
 	.close = nullptr,
 };
 
-int event_handler(void *data, const osdp_t *ctx, int pd, struct osdp_event *event) {
-	(void)(data);
-	(void)(ctx);
+class EventHandler : public OSDP::ControlPanelEventHandler
+{
+private:
+	const char* _message;
+public:
+	explicit EventHandler(const char* message) : _message{message} {}
 
-	std::cout << "PD" << pd << " EVENT: " << event->type << std::endl;
-	return 0;
-}
+	int event_handler(const OSDP::ControlPanel& cp, 
+					   int pd, struct osdp_event *event) override
+	{
+		(void)(cp);
+		std::cout << "PD " << pd << " EVENT: " << event->type << std::endl;
+		std::cout << _message << std::endl;
+		return 0;
+	}
+};
 
 int main()
 {
@@ -66,11 +75,12 @@ int main()
 
 	cp.setup(&cp_channel, 1, pd_info);
 
-	cp.set_event_callback(event_handler, nullptr);
+	EventHandler handler { "Hello world!" };
+
+	cp.set_event_callback(&handler);
 
 	while (1) {
 		// your application code.
-
 		cp.refresh();
 		std::this_thread::sleep_for(std::chrono::microseconds(10 * 1000));
 	}

examples/platformio/cp.ino

@@ -58,14 +58,23 @@ void init_cp_info()
     cp_channel.send = serial1_send_func;
 }
 
-int event_handler(void *data, const osdp_t *ctx, int pd, struct osdp_event *event)
+class EventHandler : public OSDP::ControlPanelEventHandler
 {
-    (void)(data);
-    (void)(ctx);
+private:
+	const char* _message;
+public:
+	explicit EventHandler(const char* message) : _message{message} {}
 
-    Serial.println("Received an event!");
-    return 0;
-}
+	int event_handler(const OSDP::ControlPanel& cp, 
+					   int pd, struct osdp_event *event) override
+	{
+		(void)(cp);
+		(void)(pd);
+		(void)(event);
+		Serial.println("Received an event!");
+        return 0;
+	}
+};
 
 void setup()
 {
@@ -76,7 +85,9 @@ void setup()
 
     init_cp_info();
     cp.setup(&cp_channel, 1, pd_info);
-    cp.set_event_callback(event_handler, nullptr);
+
+	EventHandler handler { "Hello world!" };
+    cp.set_event_callback(&handler);
 }
 
 void loop()

include/osdp.hpp

@@ -71,6 +71,13 @@ class OSDP_EXPORT Common {
 	osdp_t *_ctx;
 };
 
+class ControlPanel;
+
+class OSDP_EXPORT ControlPanelEventHandler {
+public:
+	virtual int event_handler(const ControlPanel& cp, int pd, struct osdp_event *ev) = 0;
+};
+
 class OSDP_EXPORT ControlPanel : public Common {
 public:
 	ControlPanel() {}
@@ -127,9 +134,9 @@ class OSDP_EXPORT ControlPanel : public Common {
 		return osdp_cp_flush_commands(_ctx, pd);
 	}
 
-	void set_event_callback(cp_event_callback_t cb, void *arg)
+	void set_event_callback(ControlPanelEventHandler *cb)
 	{
-		osdp_cp_set_event_callback(_ctx, cb, arg);
+		osdp_cp_set_event_callback(_ctx, ControlPanel::event_callback, cb);
 	}
 
 	void set_command_completion_callback(cp_command_completion_callback_t cb,
@@ -168,6 +175,17 @@ class OSDP_EXPORT ControlPanel : public Common {
 		return osdp_cp_is_pd_enabled(_ctx, pd);
 	}
 
+private:
+	static int event_callback(void *arg, const osdp_t *ctx, int pd,
+				   struct osdp_event *ev)
+	{
+		ControlPanel cp;
+		cp._ctx = const_cast<osdp_t *>(ctx); 
+		int result = static_cast<ControlPanelEventHandler*>(arg)
+			->event_handler(const_cast<const ControlPanel&>(cp), pd, ev);
+		cp._ctx = nullptr; 
+		return result;
+	}
 };
 
 class OSDP_EXPORT PeripheralDevice : public Common {