🎨 NULL => nullptr

Marlin/src/HAL/STM32/Sd2Card_sdio_stm32duino.cpp

 
 bool SDIO_ReadBlock(uint32_t block, uint8_t *dst) {
   uint8_t retries = SDIO_READ_RETRIES;
-  while (retries--) if (SDIO_ReadWriteBlock_DMA(block, NULL, dst)) return true;
+  while (retries--) if (SDIO_ReadWriteBlock_DMA(block, nullptr, dst)) return true;
   return false;
 }
 
 bool SDIO_WriteBlock(uint32_t block, const uint8_t *src) {
   uint8_t retries = SDIO_READ_RETRIES;
-  while (retries--) if (SDIO_ReadWriteBlock_DMA(block, src, NULL)) return true;
+  while (retries--) if (SDIO_ReadWriteBlock_DMA(block, src, nullptr)) return true;
   return false;
 }
 

Marlin/src/HAL/STM32F1/SPI.h

   spi_dev *spi_d;
   dma_channel spiRxDmaChannel, spiTxDmaChannel;
   dma_dev* spiDmaDev;
-  void (*receiveCallback)() = NULL;
-  void (*transmitCallback)() = NULL;
+  void (*receiveCallback)() = nullptr;
+  void (*transmitCallback)() = nullptr;
 
   friend class SPIClass;
 };

Marlin/src/lcd/extui/mks_ui/draw_cloud_bind.cpp

 
 extern lv_group_t * g;
 static lv_obj_t * scr;
-static lv_obj_t *button_bind_or_not = NULL, *label_bind_or_not = NULL;
-static lv_obj_t *buttonReleaseBind = NULL, *label_ReleaseBind = NULL;
+static lv_obj_t *button_bind_or_not = nullptr, *label_bind_or_not = nullptr;
+static lv_obj_t *buttonReleaseBind = nullptr, *label_ReleaseBind = nullptr;
 static lv_obj_t * text_id;
 
 static uint8_t unbinding_flag = 0;
 }
 
 void lv_draw_cloud_bind() {
-  lv_obj_t *buttonBack = NULL, *label_Back = NULL;
+  lv_obj_t *buttonBack = nullptr, *label_Back = nullptr;
   scr = lv_screen_create(BIND_UI);
 
-  button_bind_or_not = lv_btn_create(scr, NULL);
+  button_bind_or_not = lv_btn_create(scr, nullptr);
   lv_obj_set_pos(button_bind_or_not, TFT_WIDTH - 130, TFT_HEIGHT - 80 * 3);
   lv_obj_set_size(button_bind_or_not, PARA_UI_VALUE_BTN_X_SIZE + 15, PARA_UI_VALUE_BTN_Y_SIZE + 15);
-  lv_obj_set_event_cb_mks(button_bind_or_not, event_handler, ID_CLOUD_BIND_OR_NOT, NULL, 0);
+  lv_obj_set_event_cb_mks(button_bind_or_not, event_handler, ID_CLOUD_BIND_OR_NOT, nullptr, 0);
   lv_btn_set_style(button_bind_or_not, LV_BTN_STYLE_REL, &style_para_value);
   lv_btn_set_style(button_bind_or_not, LV_BTN_STYLE_PR, &style_para_value);
   label_bind_or_not = lv_label_create_empty(button_bind_or_not);
 
-  buttonReleaseBind = lv_btn_create(scr, NULL);
+  buttonReleaseBind = lv_btn_create(scr, nullptr);
   lv_obj_set_pos(buttonReleaseBind, TFT_WIDTH - 130, TFT_HEIGHT - 80 * 2);
   lv_obj_set_size(buttonReleaseBind, PARA_UI_VALUE_BTN_X_SIZE + 15, PARA_UI_VALUE_BTN_Y_SIZE + 15);
-  lv_obj_set_event_cb_mks(buttonReleaseBind, event_handler, ID_CLOUD_RELEASE_BIND, NULL, 0);
+  lv_obj_set_event_cb_mks(buttonReleaseBind, event_handler, ID_CLOUD_RELEASE_BIND, nullptr, 0);
   label_ReleaseBind = lv_label_create_empty(buttonReleaseBind);
   lv_label_set_text(label_ReleaseBind, cloud_menu.unbind);
   lv_obj_align(label_ReleaseBind, buttonReleaseBind, LV_ALIGN_CENTER, 0, 0);
 
-  buttonBack = lv_btn_create(scr, NULL);
+  buttonBack = lv_btn_create(scr, nullptr);
   lv_obj_set_pos(buttonBack, TFT_WIDTH - 130, TFT_HEIGHT - 80);
   lv_obj_set_size(buttonBack, PARA_UI_VALUE_BTN_X_SIZE + 15, PARA_UI_VALUE_BTN_Y_SIZE + 15);
-  lv_obj_set_event_cb_mks(buttonBack, event_handler, ID_CLOUD_BIND_RETURN, NULL, 0);
+  lv_obj_set_event_cb_mks(buttonBack, event_handler, ID_CLOUD_BIND_RETURN, nullptr, 0);
   lv_btn_set_style(buttonBack, LV_BTN_STYLE_REL, &style_para_back);
   lv_btn_set_style(buttonBack, LV_BTN_STYLE_PR, &style_para_back);
   label_Back = lv_label_create_empty(buttonBack);

Marlin/src/lcd/extui/mks_ui/draw_dialog.cpp

     }
     else if (DIALOG_IS(TYPE_UPDATE_ESP_FIRMWARE)) {
       lv_label_set_text(labelDialog, DIALOG_UPDATE_WIFI_FIRMWARE_EN);
-      lv_obj_align(labelDialog, NULL, LV_ALIGN_CENTER, 0, -20);
+      lv_obj_align(labelDialog, nullptr, LV_ALIGN_CENTER, 0, -20);
     }
   #endif // MKS_WIFI_MODULE
   else if (DIALOG_IS(TYPE_FILAMENT_LOAD_HEAT)) {
   #if ENABLED(MKS_WIFI_MODULE)
     else if (DIALOG_IS(TYPE_UNBIND)) {
       lv_label_set_text(labelDialog, common_menu.unbind_printer_tips);
-      lv_obj_align(labelDialog, NULL, LV_ALIGN_CENTER, 0, -70);
+      lv_obj_align(labelDialog, nullptr, LV_ALIGN_CENTER, 0, -70);
     }
   #endif
   #if HAS_ROTARY_ENCODER

Marlin/src/lcd/extui/mks_ui/draw_move_motor.cpp

   lv_big_button_create(scr, "F:/bmp_return.bin", common_menu.text_back, BTN_X_PIXEL * 3 + INTERVAL_V * 4, BTN_Y_PIXEL + INTERVAL_H + titleHeight, event_handler, ID_M_RETURN);
 
   // We need to patch the title to leave some space on the right for displaying the status
-  lv_obj_t * title = lv_obj_get_child_back(scr, NULL);
-  if (title != NULL) lv_obj_set_width(title, TFT_WIDTH - 101);
+  lv_obj_t * title = lv_obj_get_child_back(scr, nullptr);
+  if (title != nullptr) lv_obj_set_width(title, TFT_WIDTH - 101);
   labelP = lv_label_create(scr, TFT_WIDTH - 100, TITLE_YPOS, "Z:0.0mm");
-  if (labelP != NULL)
+  if (labelP != nullptr)
     updatePosTask = lv_task_create(refresh_pos, 300, LV_TASK_PRIO_LOWEST, 0);
 
   disp_move_dist();

Marlin/src/lcd/tft/tft_queue.h

   public:
     static void reset();
     static void async();
-    static void sync() { while (current_task != NULL) async(); }
+    static void sync() { while (current_task != nullptr) async(); }
 
     static void fill(uint16_t x, uint16_t y, uint16_t width, uint16_t height, uint16_t color);
     static void canvas(uint16_t x, uint16_t y, uint16_t width, uint16_t height);

Marlin/src/lcd/tft/touch.h

 
   public:
     static void init();
-    static void reset() { controls_count = 0; touch_time = 0; current_control = NULL; }
+    static void reset() { controls_count = 0; touch_time = 0; current_control = nullptr; }
     static void clear() { controls_count = 0; }
     static void idle();
     static bool is_clicked() {