Implement custom delay/millis for EXTENSIBLE_UI (#12188)

Marlin/src/lcd/extensible_ui/ui_api.h

@@ -1,3 +1,25 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (C) 2016 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (C) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
 /************
  * ui_api.h *
  ************/
@@ -127,6 +149,9 @@ namespace UI {
     #endif
   #endif
 
+  // This safe_millis is safe to use even when printer is killed (as long as called at least every 1 second)
+  uint32_t safe_millis();
+  void delay_us(unsigned long us);
   void delay_ms(unsigned long ms);
   void yield(); // Within lengthy loop, call this periodically