Redraw status when scrolling

Marlin/src/lcd/e3v2/marlinui/ui_common.cpp

@@ -154,48 +154,69 @@ void MarlinUI::draw_kill_screen() {
   lcd_put_u8str_P((const char*)GET_TEXT_F(MSG_HALTED));
 }
 
+//
+// Status Message
+//
 void MarlinUI::draw_status_message(const bool blink) {
-
   set_font(DWIN_FONT_STAT);
   set_dwin_text_solid(true);
   set_dwin_text_fg(Color_White);
   set_dwin_text_bg(Color_Bg_Black);
   lcd_moveto_xy(0, LCD_PIXEL_HEIGHT - (STAT_FONT_HEIGHT) - 1);
 
+  constexpr uint8_t max_status_chars = (LCD_PIXEL_WIDTH) / (STAT_FONT_WIDTH);
+
+  uint8_t status_changed = []{
+    static uint8_t old_hash = 0;
+    uint8_t hash = 0x00;
+    for (uint8_t i = 0; i < MAX_MESSAGE_LENGTH; i++) {
+      const char c = ui.status_message[i];
+      if (!c) break;
+      hash = ((hash << 1) | (hash >> 7)) ^ c;
+    }
+    const bool hash_changed = hash != old_hash;
+    old_hash = hash;
+    return hash_changed || !ui.did_first_redraw;
+  };
+
   #if ENABLED(STATUS_MESSAGE_SCROLLING)
     static bool last_blink = false;
 
     // Get the UTF8 character count of the string
     uint8_t slen = utf8_strlen(status_message);
 
     // If the string fits into the LCD, just print it and do not scroll it
-    if (slen <= (LCD_PIXEL_WIDTH) / (STAT_FONT_WIDTH)) {
+    if (slen <= max_status_chars) {
+
+      if (status_changed()) {
 
-      // The string isn't scrolling and may not fill the screen
-      lcd_put_u8str(status_message);
+        // The string isn't scrolling and may not fill the screen
+        lcd_put_u8str(status_message);
 
-      // Fill the rest with spaces
-      while (slen < (LCD_PIXEL_WIDTH) / (STAT_FONT_WIDTH)) { lcd_put_wchar(' '); ++slen; }
+        // Fill the rest with spaces
+        while (slen < max_status_chars) { lcd_put_wchar(' '); ++slen; }
+      }
     }
     else {
-      // String is larger than the available space in screen.
+      // String is larger than the available line space
 
       // Get a pointer to the next valid UTF8 character
       // and the string remaining length
       uint8_t rlen;
       const char *stat = status_and_len(rlen);
-      lcd_put_u8str_max(stat, (LCD_PIXEL_WIDTH) / (STAT_FONT_WIDTH));
+      lcd_put_u8str_max(stat, max_status_chars);
 
-      // If the remaining string doesn't completely fill the screen
-      if (rlen < (LCD_PIXEL_WIDTH) / (STAT_FONT_WIDTH)) {
+      // If the string doesn't completely fill the line...
+      if (rlen < max_status_chars) {
         lcd_put_wchar('.');                   // Always at 1+ spaces left, draw a dot
-        uint8_t chars = ((LCD_PIXEL_WIDTH) / (STAT_FONT_WIDTH)) - rlen;  // Amount of space left in characters
+        uint8_t chars = max_status_chars - rlen;  // Amount of space left in characters
         if (--chars) {                        // Draw a second dot if there's space
           lcd_put_wchar('.');
           if (--chars)
             lcd_put_u8str_max(status_message, chars); // Print a second copy of the message
         }
       }
+
       if (last_blink != blink) {
         last_blink = blink;
         advance_status_scroll();
@@ -206,17 +227,17 @@ void MarlinUI::draw_status_message(const bool blink) {
 
     UNUSED(blink);
 
-    // Get the UTF8 character count of the string
-    uint8_t slen = utf8_strlen(status_message);
+    if (status_changed()) {
+      // Get the UTF8 character count of the string
+      uint8_t slen = utf8_strlen(status_message);
 
-    // Just print the string to the LCD
-    lcd_put_u8str_max(status_message, (LCD_PIXEL_WIDTH) / (STAT_FONT_WIDTH));
+      // Just print the string to the LCD
+      lcd_put_u8str_max(status_message, max_status_chars);
 
-    // Fill the rest with spaces if there are missing spaces
-    while (slen < (LCD_PIXEL_WIDTH) / (STAT_FONT_WIDTH)) {
-      lcd_put_wchar(' ');
-      ++slen;
+      // Fill the rest with spaces if there are missing spaces
+      while (slen < max_status_chars) { lcd_put_wchar(' '); ++slen; }
     }
+
   #endif
 }
 

Marlin/src/lcd/e3v2/marlinui/ui_status_480x272.cpp

@@ -358,18 +358,7 @@ void MarlinUI::draw_status_screen() {
   //
   // Status Message
   //
-  static uint8_t old_hash = 0;
-  uint8_t hash = 0x00;
-  for (uint8_t i = 0; i < MAX_MESSAGE_LENGTH; i++) {
-    const char c = ui.status_message[i];
-    if (!c) break;
-    hash = ((hash << 1) | (hash >> 7)) ^ c;
-  }
-
-  if (!ui.did_first_redraw || hash != old_hash) {
-    draw_status_message(blink);
-    old_hash = hash;
-  }
+  draw_status_message(blink);
 
   ui.did_first_redraw = true;
 }