Show minimal preheat options in menus (PR#2471)

Marlin/ultralcd.cpp

@@ -524,20 +524,17 @@ void _lcd_preheat(int endnum, const float temph, const float tempb, const int fa
 void lcd_preheat_pla0() { _lcd_preheat(0, plaPreheatHotendTemp, plaPreheatHPBTemp, plaPreheatFanSpeed); }
 void lcd_preheat_abs0() { _lcd_preheat(0, absPreheatHotendTemp, absPreheatHPBTemp, absPreheatFanSpeed); }
 
-#if TEMP_SENSOR_1 != 0 || TEMP_SENSOR_2 != 0 || TEMP_SENSOR_3 != 0 || TEMP_SENSOR_BED != 0 //more than one extruder present
-
-  #if TEMP_SENSOR_1 != 0
+#if EXTRUDERS > 1
   void lcd_preheat_pla1() { _lcd_preheat(1, plaPreheatHotendTemp, plaPreheatHPBTemp, plaPreheatFanSpeed); }
   void lcd_preheat_abs1() { _lcd_preheat(1, absPreheatHotendTemp, absPreheatHPBTemp, absPreheatFanSpeed); }
-  #endif
-  #if TEMP_SENSOR_2 != 0
+  #if EXTRUDERS > 2
     void lcd_preheat_pla2() { _lcd_preheat(2, plaPreheatHotendTemp, plaPreheatHPBTemp, plaPreheatFanSpeed); }
     void lcd_preheat_abs2() { _lcd_preheat(2, absPreheatHotendTemp, absPreheatHPBTemp, absPreheatFanSpeed); }
-  #endif
-  #if TEMP_SENSOR_3 != 0
+    #if EXTRUDERS > 3
       void lcd_preheat_pla3() { _lcd_preheat(3, plaPreheatHotendTemp, plaPreheatHPBTemp, plaPreheatFanSpeed); }
       void lcd_preheat_abs3() { _lcd_preheat(3, absPreheatHotendTemp, absPreheatHPBTemp, absPreheatFanSpeed); }
     #endif
+  #endif
 
   void lcd_preheat_pla0123() {
     setTargetHotend0(plaPreheatHotendTemp);
@@ -552,25 +549,31 @@ void lcd_preheat_abs0() { _lcd_preheat(0, absPreheatHotendTemp, absPreheatHPBTem
     _lcd_preheat(3, absPreheatHotendTemp, absPreheatHPBTemp, absPreheatFanSpeed);
   }
 
-  #if TEMP_SENSOR_0 != 0
+#endif // EXTRUDERS > 1
 
+#if TEMP_SENSOR_BED != 0
   void lcd_preheat_pla_bedonly() { _lcd_preheat(0, 0, plaPreheatHPBTemp, plaPreheatFanSpeed); }
   void lcd_preheat_abs_bedonly() { _lcd_preheat(0, 0, absPreheatHPBTemp, absPreheatFanSpeed); }
+#endif
 
 static void lcd_preheat_pla_menu() {
   START_MENU();
   MENU_ITEM(back, MSG_PREPARE, lcd_prepare_menu);
+  #if EXTRUDERS == 1
+    MENU_ITEM(function, MSG_PREHEAT_PLA, lcd_preheat_pla0);
+  #else
     MENU_ITEM(function, MSG_PREHEAT_PLA_N MSG_H1, lcd_preheat_pla0);
-      #if TEMP_SENSOR_1 != 0
+    #if EXTRUDERS > 1
       MENU_ITEM(function, MSG_PREHEAT_PLA_N MSG_H2, lcd_preheat_pla1);
-      #endif
-      #if TEMP_SENSOR_2 != 0
+      #if EXTRUDERS > 2
         MENU_ITEM(function, MSG_PREHEAT_PLA_N MSG_H3, lcd_preheat_pla2);
-      #endif
-      #if TEMP_SENSOR_3 != 0
+        #if EXTRUDERS > 3
           MENU_ITEM(function, MSG_PREHEAT_PLA_N MSG_H4, lcd_preheat_pla3);
         #endif
+      #endif
+    #endif
     MENU_ITEM(function, MSG_PREHEAT_PLA_ALL, lcd_preheat_pla0123);
+  #endif
   #if TEMP_SENSOR_BED != 0
     MENU_ITEM(function, MSG_PREHEAT_PLA_BEDONLY, lcd_preheat_pla_bedonly);
   #endif
@@ -580,25 +583,26 @@ void lcd_preheat_abs0() { _lcd_preheat(0, absPreheatHotendTemp, absPreheatHPBTem
 static void lcd_preheat_abs_menu() {
   START_MENU();
   MENU_ITEM(back, MSG_PREPARE, lcd_prepare_menu);
+  #if EXTRUDERS == 1
+    MENU_ITEM(function, MSG_PREHEAT_ABS, lcd_preheat_abs0);
+  #else
     MENU_ITEM(function, MSG_PREHEAT_ABS_N MSG_H1, lcd_preheat_abs0);
-      #if TEMP_SENSOR_1 != 0
+    #if EXTRUDERS > 1
       MENU_ITEM(function, MSG_PREHEAT_ABS_N MSG_H2, lcd_preheat_abs1);
-      #endif
-      #if TEMP_SENSOR_2 != 0
+      #if EXTRUDERS > 2
         MENU_ITEM(function, MSG_PREHEAT_ABS_N MSG_H3, lcd_preheat_abs2);
-      #endif
-      #if TEMP_SENSOR_3 != 0
+        #if EXTRUDERS > 3
           MENU_ITEM(function, MSG_PREHEAT_ABS_N MSG_H4, lcd_preheat_abs3);
         #endif
+      #endif
+    #endif
     MENU_ITEM(function, MSG_PREHEAT_ABS_ALL, lcd_preheat_abs0123);
+  #endif
   #if TEMP_SENSOR_BED != 0
     MENU_ITEM(function, MSG_PREHEAT_ABS_BEDONLY, lcd_preheat_abs_bedonly);
   #endif
   END_MENU();
 }
-  #endif
-
-#endif // more than one temperature sensor present
 
 void lcd_cooldown() {
   disable_all_heaters();