From 68b3c8b8e87e0ef01f94653fade70d23d8f5f493 Mon Sep 17 00:00:00 2001
From: Marcio Teixeira <marcio@alephobjects.com>
Date: Tue, 5 Sep 2017 08:18:34 -0600
Subject: [PATCH] Long filenames now scroll (T335)

---
 Marlin/Conditionals_LulzBot.h |  1 +
 Marlin/SdFatConfig.h          |  4 ++++
 Marlin/ultralcd.cpp           |  9 +++++++++
 Marlin/ultralcd_impl_DOGM.h   | 22 ++++++++++++++++++----
 4 files changed, 32 insertions(+), 4 deletions(-)

diff --git a/Marlin/Conditionals_LulzBot.h b/Marlin/Conditionals_LulzBot.h
index 0b2822109..e7099b5c7 100644
--- a/Marlin/Conditionals_LulzBot.h
+++ b/Marlin/Conditionals_LulzBot.h
@@ -478,6 +478,7 @@
      */
     #define LULZBOT_HIDE_ACTIVE_NOZZLE_IN_LCD
     #define LULZBOT_HIDE_PID_CONFIG_IN_LCD
+    #define LULZBOT_SCROLL_LONG_FILE_NAMES
 #endif
 
 /*********************************************** COMMON TOOLHEADS PARAMETERS *****************************/
diff --git a/Marlin/SdFatConfig.h b/Marlin/SdFatConfig.h
index d3406a028..9b3ba7e08 100644
--- a/Marlin/SdFatConfig.h
+++ b/Marlin/SdFatConfig.h
@@ -125,7 +125,11 @@
   * Defines for long (vfat) filenames
   */
   /** Number of VFAT entries used. Every entry has 13 UTF-16 characters */
+  #if defined(LULZBOT_SCROLL_LONG_FILE_NAMES)
+  #define MAX_VFAT_ENTRIES (5)
+  #else
   #define MAX_VFAT_ENTRIES (2)
+  #endif
   /** Total size of the buffer used to store the long filenames */
   #define LONG_FILENAME_LENGTH (FILENAME_LENGTH*MAX_VFAT_ENTRIES+1)
 #endif  // SdFatConfig_h
diff --git a/Marlin/ultralcd.cpp b/Marlin/ultralcd.cpp
index 8988fbacc..7ba58c6f3 100644
--- a/Marlin/ultralcd.cpp
+++ b/Marlin/ultralcd.cpp
@@ -4353,6 +4353,15 @@ void lcd_update() {
       lcdDrawUpdate = LCDVIEW_REDRAW_NOW;
     }
 
+    #if ENABLED(LULZBOT_SCROLL_LONG_FILE_NAMES)
+      if(currentScreen == lcd_sdcard_menu && scroll_offset < scroll_max && !lcd_status_update_delay--) {
+        lcd_status_update_delay = 6;
+        lcdDrawUpdate = LCDVIEW_REDRAW_NOW;
+        scroll_offset++;
+        return_to_status_ms = ms + LCD_TIMEOUT_TO_STATUS;
+      }
+    #endif
+
     // then we want to use 1/2 of the time only.
     uint16_t bbr2 = planner.block_buffer_runtime() >> 1;
 
diff --git a/Marlin/ultralcd_impl_DOGM.h b/Marlin/ultralcd_impl_DOGM.h
index 7b2e2aa12..ccb8fb14f 100644
--- a/Marlin/ultralcd_impl_DOGM.h
+++ b/Marlin/ultralcd_impl_DOGM.h
@@ -755,6 +755,12 @@ static void lcd_implementation_status_screen() {
 
   #endif // ADVANCED_PAUSE_FEATURE
 
+  #if defined(LULZBOT_SCROLL_LONG_FILE_NAMES)
+    static int        scroll_offset;
+    static int        scroll_max;
+    static int        scroll_row;
+  #endif
+
   // Set the colors for a menu item based on whether it is selected
   static void lcd_implementation_mark_as_selected(const uint8_t row, const bool isSelected) {
     row_y1 = row * row_height + 1;
@@ -941,14 +947,22 @@ static void lcd_implementation_status_screen() {
       uint8_t n = LCD_WIDTH - (START_COL) - 1;
       if (longFilename[0]) {
         filename = longFilename;
-        longFilename[n] = '\0';
+        #if defined(LULZBOT_SCROLL_LONG_FILE_NAMES)
+          if (isSelected) {
+            if(scroll_row != row) {
+              scroll_max    = max(0, strlen(longFilename) - n);
+              scroll_row    = row;
+              scroll_offset = 0;
+            }
+            filename += scroll_offset;
+          }
+        #endif
       }
 
       if (isDir) lcd_print(LCD_STR_FOLDER[0]);
 
-      while (char c = *filename) {
-        n -= lcd_print_and_count(c);
-        filename++;
+      for(const char *c = filename; *c && n > 0; c++) {
+        n -= lcd_print_and_count(*c);
       }
       while (n--) u8g.print(' ');
     }