rough draft a callback inside HardwareAbstract

to show concept.

Platformio/HAL/HardwareAbstract.cpp

@@ -19,3 +19,13 @@ std::optional<HardwareAbstract::batteryStatus> HardwareAbstract::getBatteryStatu
     }
     return std::nullopt;
 }
+
+  void HardwareAbstract::notifyBatteryChange(HardwareAbstract::batteryStatus aStatus){
+    for (auto handler : mBatteryEventHandlers){
+        handler(aStatus);
+    }
+  }
+
+  void HardwareAbstract::onBatteryChange(std::function<void(HardwareAbstract::batteryStatus)> onBatteryStatusChangeHandler){
+    mBatteryEventHandlers.push_back(std::move(onBatteryStatusChangeHandler));
+  }

Platformio/HAL/HardwareAbstract.hpp

@@ -2,10 +2,12 @@
 // 2023 Matthew Colvin
 
 #pragma once
+#include <functional>
 #include <lvgl.h>
 #include <memory>
 #include <optional>
 #include <string>
+#include <vector>
 #include "BatteryInterface.h"
 #include "DisplayInterface.h"
 #include "wifiHandlerInterface.h"
@@ -34,6 +36,10 @@ public:
   /// @param message - Debug message
   virtual void debugPrint(std::string message) = 0;
 
+  // Didn't actually implement this but would need to set up something to intermittently notify of batteryChange.
+  void notifyBatteryChange(batteryStatus aStatus);
+  void onBatteryChange(std::function<void(batteryStatus)> onBatteryStatusChangeHandler);
+
   private:
     std::shared_ptr<BatteryInterface> mBattery;
     std::shared_ptr<wifiHandlerInterface> mWifiHandler;

Platformio/OmoteUI/OmoteUI.cpp

@@ -307,6 +307,11 @@ void OmoteUI::layout_UI() {
   lv_obj_set_style_bg_color(menuBox, color_primary, LV_PART_MAIN);
   lv_obj_set_style_border_width(menuBox, 0, LV_PART_MAIN);
 
+  mHardware->onBatteryChange([menuLabel](HardwareAbstract::batteryStatus aCurrentBattery){
+    // I dont know enough about lvgl to do this but basically take aCurrentBattery and update UI elements here.
+    // See Notice menuLabel is captured and useable here.
+  });
+
   // Add content to the smart home tab (4)
 
   lv_obj_set_layout(tab4, LV_LAYOUT_FLEX);