Adherence to the new OOP coding standards

Marlin/Marlin.h

 #endif
 
 // Print job timer
-extern stopwatch print_job_timer;
+extern Stopwatch print_job_timer;
 
 // Handling multiple extruders pins
 extern uint8_t active_extruder;

Marlin/Marlin_main.cpp

 millis_t previous_cmd_ms = 0;
 static millis_t max_inactive_time = 0;
 static millis_t stepper_inactive_time = (DEFAULT_STEPPER_DEACTIVE_TIME) * 1000L;
-stopwatch print_job_timer = stopwatch();
+Stopwatch print_job_timer = Stopwatch();
 static uint8_t target_extruder;
 
 #if ENABLED(AUTO_BED_LEVELING_FEATURE)
     #endif
 
     /**
-     * We use halve EXTRUDE_MINTEMP here to allow nozzles to be put into hot
+     * We use half EXTRUDE_MINTEMP here to allow nozzles to be put into hot
      * stand by mode, for instance in a dual extruder setup, without affecting
      * the running print timer.
      */
-    if (temp <= (EXTRUDE_MINTEMP/2)) {
+    if (temp <= (EXTRUDE_MINTEMP)/2) {
       print_job_timer.stop();
       LCD_MESSAGEPGM(WELCOME_MSG);
     }
     /**
      * We do not check if the timer is already running because this check will
-     * be done for us inside the stopwatch::start() method thus a running timer
+     * be done for us inside the Stopwatch::start() method thus a running timer
      * will not restart.
      */
     else print_job_timer.start();
     #endif
 
     /**
-     * We use halve EXTRUDE_MINTEMP here to allow nozzles to be put into hot
+     * We use half EXTRUDE_MINTEMP here to allow nozzles to be put into hot
      * stand by mode, for instance in a dual extruder setup, without affecting
      * the running print timer.
      */
-    if (temp <= (EXTRUDE_MINTEMP/2)) {
+    if (temp <= (EXTRUDE_MINTEMP)/2) {
       print_job_timer.stop();
       LCD_MESSAGEPGM(WELCOME_MSG);
     }
     /**
      * We do not check if the timer is already running because this check will
-     * be done for us inside the stopwatch::start() method thus a running timer
+     * be done for us inside the Stopwatch::start() method thus a running timer
      * will not restart.
      */
     else print_job_timer.start();

Marlin/stopwatch.cpp

 #include "Marlin.h"
 #include "stopwatch.h"
 
-stopwatch::stopwatch() {
+Stopwatch::Stopwatch() {
    this->reset();
  }
 
-void stopwatch::stop() {
-  if (DEBUGGING(INFO)) SERIAL_ECHOLNPGM("stopwatch::stop()");
+void Stopwatch::stop() {
+  if (DEBUGGING(INFO)) SERIAL_ECHOLNPGM("Stopwatch::stop()");
   if (!this->isRunning()) return;
 
   this->status = STPWTCH_STOPPED;
   this->stopTimestamp = millis();
 }
 
-void stopwatch::pause() {
-  if (DEBUGGING(INFO)) SERIAL_ECHOLNPGM("stopwatch::pause()");
+void Stopwatch::pause() {
+  if (DEBUGGING(INFO)) SERIAL_ECHOLNPGM("Stopwatch::pause()");
   if (!this->isRunning()) return;
 
   this->status = STPWTCH_PAUSED;
   this->stopTimestamp = millis();
 }
 
-void stopwatch::start() {
-  if (DEBUGGING(INFO)) SERIAL_ECHOLNPGM("stopwatch::start()");
+void Stopwatch::start() {
+  if (DEBUGGING(INFO)) SERIAL_ECHOLNPGM("Stopwatch::start()");
   if (this->isRunning()) return;
 
   if (this->isPaused()) this->accumulator = this->duration();
   this->startTimestamp = millis();
 }
 
-void stopwatch::reset() {
-  if (DEBUGGING(INFO)) SERIAL_ECHOLNPGM("stopwatch::reset()");
+void Stopwatch::reset() {
+  if (DEBUGGING(INFO)) SERIAL_ECHOLNPGM("Stopwatch::reset()");
 
   this->status = STPWTCH_STOPPED;
   this->startTimestamp = 0;
   this->accumulator = 0;
 }
 
-bool stopwatch::isRunning() {
+bool Stopwatch::isRunning() {
   return (this->status == STPWTCH_RUNNING) ? true : false;
 }
 
-bool stopwatch::isPaused() {
+bool Stopwatch::isPaused() {
   return (this->status == STPWTCH_PAUSED) ? true : false;
 }
 
-uint16_t stopwatch::duration() {
+uint16_t Stopwatch::duration() {
   return (((this->isRunning()) ? millis() : this->stopTimestamp)
           - this->startTimestamp) / 1000 + this->accumulator;
 }

Marlin/stopwatch.h

 #ifndef STOPWATCH_H
 #define STOPWATCH_H
 
-enum stopwatch_s {
+enum StopwatchStatus {
   STPWTCH_STOPPED = 0x0,
   STPWTCH_RUNNING = 0x1,
   STPWTCH_PAUSED  = 0x2
  * @details This class acts as a timer proving stopwatch functionality including
  * the ability to pause the running time counter.
  */
-class stopwatch {
+class Stopwatch {
   private:
-    stopwatch_s status;
+    StopwatchStatus status;
     uint16_t accumulator;
     uint32_t startTimestamp;
     uint32_t stopTimestamp;
     /**
      * @brief Class constructor
      */
-    stopwatch();
+    Stopwatch();
 
     /**
      * @brief Stops the stopwatch