Add discharging status

main/boards/xingzhi-cube-1.54tft-wifi/power_manager.h

@@ -167,6 +167,11 @@ public:
         return is_charging_;
     }
 
+    bool IsDischarging() {
+        // 没有区分充电和放电，所以直接返回相反状态
+        return !is_charging_;
+    }
+
     uint8_t GetBatteryLevel() {
         return battery_level_;
     }

main/boards/xingzhi-cube-1.54tft-wifi/xingzhi-cube-1.54tft-wifi.cc

@@ -199,8 +199,14 @@ public:
         return &backlight;
     }
 
-    virtual bool GetBatteryLevel(int& level, bool& charging) override {
+    virtual bool GetBatteryLevel(int& level, bool& charging, bool& discharging) override {
+        static bool last_discharging = false;
         charging = power_manager_->IsCharging();
+        discharging = power_manager_->IsDischarging();
+        if (discharging != last_discharging) {
+            power_save_timer_->SetEnabled(discharging);
+            last_discharging = discharging;
+        }
         level = power_manager_->GetBatteryLevel();
         return true;
     }