From 0527344d37ec4eb3d991eb58549ea2da72bf405d Mon Sep 17 00:00:00 2001
From: Chris Hatton <christopherhattonuk@gmail.com>
Date: Fri, 10 Apr 2020 22:35:29 +1000
Subject: [PATCH 1/3] Add support for using std::function callbacks instead of
 C-pointers

---
 src/MqttClient.cpp | 15 +++++++++++++++
 src/MqttClient.h   | 16 ++++++++++++++++
 2 files changed, 31 insertions(+)

diff --git a/src/MqttClient.cpp b/src/MqttClient.cpp
index 8e2684e..1bd0eb2 100644
--- a/src/MqttClient.cpp
+++ b/src/MqttClient.cpp
@@ -97,10 +97,17 @@ MqttClient::~MqttClient()
   }
 }
 
+#ifdef MQTT_CLIENT_STD_FUNCTION_CALLBACK
+void MqttClient::onMessage(MqttMessageCallback callback)
+{
+  _onMessage = callback;
+}
+#else
 void MqttClient::onMessage(void(*callback)(int))
 {
   _onMessage = callback;
 }
+#endif
 
 int MqttClient::parseMessage()
 {
@@ -550,7 +557,11 @@ void MqttClient::poll()
             _rxState = MQTT_CLIENT_RX_STATE_READ_PUBLISH_PAYLOAD;
 
             if (_onMessage) {
+#ifdef MQTT_CLIENT_STD_FUNCTION_CALLBACK
+              _onMessage(this,_rxLength);
+#else
               _onMessage(_rxLength);
+#endif
 
               if (_rxLength == 0) {
                 _rxState = MQTT_CLIENT_RX_STATE_READ_TYPE;
@@ -573,7 +584,11 @@ void MqttClient::poll()
           _rxState = MQTT_CLIENT_RX_STATE_READ_PUBLISH_PAYLOAD;
 
           if (_onMessage) {
+#ifdef MQTT_CLIENT_STD_FUNCTION_CALLBACK
+            _onMessage(this,_rxLength);
+#else
             _onMessage(_rxLength);
+#endif
           }
 
           if (_rxLength == 0) {
diff --git a/src/MqttClient.h b/src/MqttClient.h
index e0e9d63..4382e3b 100644
--- a/src/MqttClient.h
+++ b/src/MqttClient.h
@@ -32,12 +32,24 @@
 #define MQTT_BAD_USER_NAME_OR_PASSWORD      4
 #define MQTT_NOT_AUTHORIZED                 5
 
+// Make this definition in your application code to use std::functions for onMessage callbacks instead of C-pointers:
+// #define MQTT_CLIENT_STD_FUNCTION_CALLBACK
+
+#ifdef MQTT_CLIENT_STD_FUNCTION_CALLBACK
+#include <functional>
+#endif
+
 class MqttClient : public Client {
 public:
   MqttClient(Client& client);
   virtual ~MqttClient();
 
+#ifdef MQTT_CLIENT_STD_FUNCTION_CALLBACK
+  typedef std::function<void(MqttClient *client, int messageSize)> MessageCallback;
+  void onMessage(MessageCallback callback);
+#else
   void onMessage(void(*)(int));
+#endif
 
   int parseMessage();
   String messageTopic() const;
@@ -128,7 +140,11 @@ class MqttClient : public Client {
 private:
   Client* _client;
 
+#ifdef MQTT_CLIENT_STD_FUNCTION_CALLBACK
+  MqttClient::MessageCallback _onMessage;
+#else
   void (*_onMessage)(int);
+#endif
 
   String _id;
   String _username;

From 9d22ef1a2f9d197cba2fa0873abe97f13f9bdc7c Mon Sep 17 00:00:00 2001
From: Chris Hatton <christopherhattonuk@gmail.com>
Date: Fri, 10 Apr 2020 22:52:23 +1000
Subject: [PATCH 2/3] Remove some redundancy

---
 src/MqttClient.cpp | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/src/MqttClient.cpp b/src/MqttClient.cpp
index 1bd0eb2..ff7cf61 100644
--- a/src/MqttClient.cpp
+++ b/src/MqttClient.cpp
@@ -99,15 +99,12 @@ MqttClient::~MqttClient()
 
 #ifdef MQTT_CLIENT_STD_FUNCTION_CALLBACK
 void MqttClient::onMessage(MqttMessageCallback callback)
-{
-  _onMessage = callback;
-}
 #else
 void MqttClient::onMessage(void(*callback)(int))
+#endif
 {
   _onMessage = callback;
 }
-#endif
 
 int MqttClient::parseMessage()
 {

From 0179fcdc5a9f789b3b12b8bd52579bb9f180671c Mon Sep 17 00:00:00 2001
From: Chris Hatton <christopherhattonuk@gmail.com>
Date: Sat, 11 Apr 2020 00:46:50 +1000
Subject: [PATCH 3/3] Fix compile error & redundant class qualifier.

---
 src/MqttClient.cpp | 2 +-
 src/MqttClient.h   | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/MqttClient.cpp b/src/MqttClient.cpp
index ff7cf61..0ab6863 100644
--- a/src/MqttClient.cpp
+++ b/src/MqttClient.cpp
@@ -98,7 +98,7 @@ MqttClient::~MqttClient()
 }
 
 #ifdef MQTT_CLIENT_STD_FUNCTION_CALLBACK
-void MqttClient::onMessage(MqttMessageCallback callback)
+void MqttClient::onMessage(MessageCallback callback)
 #else
 void MqttClient::onMessage(void(*callback)(int))
 #endif
diff --git a/src/MqttClient.h b/src/MqttClient.h
index 4382e3b..27c1787 100644
--- a/src/MqttClient.h
+++ b/src/MqttClient.h
@@ -141,7 +141,7 @@ class MqttClient : public Client {
   Client* _client;
 
 #ifdef MQTT_CLIENT_STD_FUNCTION_CALLBACK
-  MqttClient::MessageCallback _onMessage;
+  MessageCallback _onMessage;
 #else
   void (*_onMessage)(int);
 #endif