save color on OFF

include/myled.h

@@ -4,6 +4,16 @@
 
 class MyLed {
 public:
+    typedef std::array<uint8_t, 3> ColorArr;
+
+    typedef std::function<void()> CallbackFunc;
+
+    typedef struct {
+        ColorArr color;
+        uint8_t brightness;
+        bool isOn;
+    } State;
+
     MyLed(int ledPin, int ledCount, bool effects = false);
 
     void initialize();
@@ -14,7 +24,7 @@ public:
 
     void toggle();
 
-    //! @param state Json package
+    //! @param jsonState Json package
     //!              {
     //!                "brightness": 255,
     //!                "color": {
@@ -26,8 +36,13 @@ public:
     //!              }
     void set(String jsonState);
 
+    void setState(State);
+
+    //! @return a Json string on the same format as for MyLed::set(jsonState)
     String get();
 
+    State getState();
+
     //! @param brightness in [0, 1]
     void setBrightness(float brightness);
 
@@ -38,10 +53,11 @@ public:
 
     void run();
 
-private:
-    void _apply();
+    //! @param CallbackFunc will be called when the LED is turned off
+    void registerOffCallback(CallbackFunc);
 
-    typedef std::array<uint8_t, 3> ColorArr;
+private:
+    void apply();
 
     bool _useEffects;
 
@@ -54,4 +70,6 @@ private:
     const ColorArr _defColor;
 
     ColorArr _color;
+
+    CallbackFunc _callback;
 };

src/main.cpp

@@ -159,6 +159,21 @@ void mqttCallback(char* topic, byte* payload, unsigned int length)
     }
 }
 
+void offCallback()
+{
+    auto state = myLed.getState();
+    if (config.data.color == state.color &&
+        config.data.brightness == state.brightness)
+    {
+        return;
+    } else
+    {
+        config.data.color = state.color;
+        config.data.brightness = state.brightness;
+        config.write();
+    }
+}
+
 void setup()
 {
     pinMode(boardLedPin, OUTPUT);
@@ -169,8 +184,11 @@ void setup()
     Serial.begin(9600);
 
     myLed.initialize();
+    myLed.registerOffCallback(offCallback);
 
     config.load();
+    myLed.setState(
+        MyLed::State({config.data.color, config.data.brightness, true}));
     WiFi.begin(config.data.ssid, config.data.pass);
     WiFi.hostname(config.data.hostname);
     Serial.print("Connecting");

src/myled.cpp

@@ -14,6 +14,7 @@ MyLed::MyLed(int ledPin, int ledCount, bool effects)
 , _isOn(true)
 , _defColor({255, 147, 41})
 , _color(_defColor)
+, _callback(nullptr)
 {}
 
 void MyLed::initialize()
@@ -31,11 +32,14 @@ void MyLed::setOnState(bool on)
     Serial.println(on ? "Turning on" : "Turning off");
     if (on)
     {
-        _apply();
+        apply();
     } else
     {
         _strip.fill({});
         _strip.show();
+
+        if (_callback)
+            _callback();
     };
 }
 
@@ -80,6 +84,13 @@ void MyLed::set(String jsonState)
     }
 }
 
+void MyLed::setState(State s)
+{
+    setColor(s.color.at(0), s.color.at(1), s.color.at(2));
+    setBrightness(static_cast<float>(s.brightness) / 255.0f);
+    setOnState(s.isOn);
+}
+
 String MyLed::get()
 {
     return "{\"brightness\": " + String(_brightness * 255.0f) +
@@ -89,6 +100,11 @@ String MyLed::get()
            String(_isOn ? "ON" : "OFF") + "\"}";
 }
 
+MyLed::State MyLed::getState()
+{
+    return {_color, static_cast<uint8_t>(_brightness * 255.0f), _isOn};
+}
+
 void MyLed::setBrightness(float brightness)
 {
     brightness = max(minBrightness, brightness);
@@ -99,7 +115,7 @@ void MyLed::setBrightness(float brightness)
     } else
     {
         _brightness = brightness;
-        _apply();
+        apply();
     }
 }
 
@@ -112,7 +128,7 @@ void MyLed::adjustBrightness(float diff)
 void MyLed::setColor(uint8_t r, uint8_t g, uint8_t b)
 {
     _color = {r, g, b};
-    _apply();
+    apply();
 }
 
 void MyLed::run()
@@ -124,11 +140,16 @@ void MyLed::run()
         const float mixFactor = 0.2;
         _brightness =
             _brightness * (1 - mixFactor) + _targetBrightness * mixFactor;
-        _apply();
+        apply();
     }
 }
 
-void MyLed::_apply()
+void MyLed::registerOffCallback(CallbackFunc callback)
+{
+    _callback = callback;
+}
+
+void MyLed::apply()
 {
     _strip.fill(_strip.Color(static_cast<uint8_t>(_color.at(0) * _brightness),
                              static_cast<uint8_t>(_color.at(1) * _brightness),