config: add new Configuration class to simplify handling json config update api

lib/Figments/Input.h

@@ -175,19 +175,6 @@ private:
     std::function<InputEvent(const InputEvent)> m_func;
 };
 
-class ConfigTaskMixin : public virtual Loopable {
-  public:
-    void handleEvent(const InputEvent &evt) override {
-      if (evt.intent == InputEvent::ConfigurationChanged) {
-          handleConfigChange(evt);
-      }
-    }
-
-    void loop() override {}
-
-    virtual void handleConfigChange(const InputEvent& evt) {}
-};
-
 class OnlineTaskMixin : public virtual Loopable {
   public:
     void handleEvent(const InputEvent &evt) override {

src/Config.cpp

@@ -9,6 +9,50 @@
 #include <LittleFS.h>
 #include <vector>
 
+void
+ConfigTaskMixin::handleEvent(const InputEvent &evt)
+{
+  if (evt.intent == InputEvent::ConfigurationChanged) {
+      const JsonObject& cfg = *evt.as<JsonObject>();
+      handleConfigChange(Configuration(cfg));
+  }
+}
+
+Configuration::Configuration(const JsonObject& data)
+  : m_json(data)
+{
+}
+
+const char*
+Configuration::get(const char* key, const char* defaultVal) const
+{
+    if (m_json.containsKey(key)) {
+      return m_json[key];
+    } else {
+      return defaultVal;
+    }
+}
+
+int
+Configuration::get(const char* key, int defaultVal) const
+{
+    if (m_json.containsKey(key)) {
+      return m_json[key];
+    } else {
+      return defaultVal;
+    }
+}
+
+bool
+Configuration::get(const char* key, bool defaultVal) const
+{
+    if (m_json.containsKey(key)) {
+      return m_json[key];
+    } else {
+      return defaultVal;
+    }
+}
+
 StaticJsonDocument<1024> jsonConfig;
 
 constexpr uint16_t HardwareConfig::MAX_LED_NUM;

src/Config.h

@@ -1,6 +1,27 @@
 #pragma once
 #include <Figments.h>
 #include "JsonCoordinateMapping.h"
+#include <ArduinoJson.h>
+
+class Configuration {
+  public:
+    Configuration(const JsonObject& data);
+    const char* get(const char* key, const char* defaultVal) const;
+    int get(const char* key, int defaultVal) const;
+    bool get(const char* key, bool defaultVal) const;
+
+  private:
+    const JsonObject& m_json;
+};
+
+class ConfigTaskMixin : public virtual Loopable {
+  public:
+    void handleEvent(const InputEvent &evt) override;
+
+    void loop() override {}
+
+    virtual void handleConfigChange(const Configuration& config) {}
+};
 
 struct HardwareConfig {
     uint8_t version = 3;

src/animations/Power.cpp

@@ -3,18 +3,12 @@
 #include <ArduinoJson.h>
 
 void
-Power::handleConfigChange(const InputEvent& event)
+Power::handleConfigChange(const Configuration& config)
 {
-    const JsonObject& cfg = *event.as<JsonObject>();
-    if (cfg.containsKey("power.milliamps")) {
-        m_milliamps = cfg["power.milliamps"];
-    }
-    if (cfg.containsKey("power.volts")) {
-        m_voltage = cfg["power.volts"];
-    }
-    if (cfg.containsKey("power.useBPM")) {
-        m_useBPM = cfg["power.useBPM"];
-    }
+    m_milliamps = config.get("power.milliamps", m_milliamps);
+    m_voltage = config.get("power.volts", m_voltage);
+    m_useBPM = config.get("power.useBPM", m_useBPM);
+
     if (m_voltage == 0 || m_milliamps == 0) {
       Log.notice("power: Impossible power config: %dma @ %dv", m_milliamps, m_voltage);
       m_valid = false;

src/animations/Power.h

@@ -1,5 +1,6 @@
 #pragma once
 #include <Figments.h>
+#include "../Config.h"
 
 class Power: public Figment, ConfigTaskMixin {
 public:
@@ -27,7 +28,7 @@ public:
         }
     }
 
-    void handleConfigChange(const InputEvent& event) override;
+    void handleConfigChange(const Configuration& config) override;
 
     void loop() override {
         ConfigTaskMixin::loop();

src/inputs/BPM.h

@@ -1,6 +1,7 @@
 #pragma once
 #include <Figments.h>
 #include <ArduinoJson.h>
+#include "../Config.h"
 
 class BPM : public InputSource, ConfigTaskMixin {
 public:
@@ -22,13 +23,10 @@ public:
       ConfigTaskMixin::loop();
   }
 
-  void handleConfigChange(const InputEvent& evt) override {
-    const JsonObject& cfg = *evt.as<JsonObject>();
-    if (cfg.containsKey("bpm.idle")) {
-        double requestedBPM = cfg["bpm.idle"];
-        m_msPerBeat = 60000.0 / (double)requestedBPM;
-        Log.notice("bpm: idle BPM set to %u (requested %lf)", msToBPM(m_msPerBeat), requestedBPM);
-    }
+  void handleConfigChange(const Configuration& cfg) override {
+    double requestedBPM = cfg.get("bpm.idle", msToBPM(m_msPerBeat));
+    m_msPerBeat = 60000.0 / (double)requestedBPM;
+    Log.notice("bpm: idle BPM set to %d (requested %d)", (int)msToBPM(m_msPerBeat), (int)requestedBPM);
   }
 
   InputEvent read() override {

src/platform/arduino/MQTTTelemetry.cpp

@@ -200,17 +200,14 @@ MQTTTelemetry::handleEventOnline(const InputEvent& evt)
 }
 
 void
-MQTTTelemetry::handleConfigChange(const InputEvent& event)
+MQTTTelemetry::handleConfigChange(const Configuration& cfg)
 {
   Log.notice("Config change in mqtt");
-  const JsonObject* obj = event.as<JsonObject>();
-  if (obj->containsKey("mqtt.ip")) {
-    const char* newIP = (*obj)["mqtt.ip"].as<JsonString>().c_str();
-    Log.notice("ip: %s", newIP);
-    strncpy(m_hostBuf, newIP, sizeof(m_hostBuf));
-    m_hostBuf[sizeof(m_hostBuf)-1] = 0;
-    m_mqtt.disconnect();
-  }
+  const char* newIP = cfg.get("mqtt.ip", m_hostBuf);
+  Log.notice("ip: %s", newIP);
+  strncpy(m_hostBuf, newIP, sizeof(m_hostBuf));
+  m_hostBuf[sizeof(m_hostBuf)-1] = 0;
+  m_mqtt.disconnect();
 }
 
 void

src/platform/arduino/MQTTTelemetry.h

@@ -3,6 +3,7 @@
 
 #include <PubSubClient.h>
 #include <ArduinoLog.h>
+#include "../../Config.h"
 
 #include "../../Sequencer.h"
 
@@ -47,7 +48,7 @@ class MQTTTelemetry : public BufferedInputSource, OnlineTaskMixin, ConfigTaskMix
 
     void handleEvent(const InputEvent& evt) override;
     void handleEventOnline(const InputEvent& evt) override;
-    void handleConfigChange(const InputEvent& evt) override;
+    void handleConfigChange(const Configuration& cfg) override;
     void loop() override;
 
     void loopOnline() override;