MSG feature for display.

Thomas dl3el wrote this feature for displaying the the last personal aprs-messages.
  Thomas dl9sau modified: don't overwrite a personal aprs-message with winlink notification.
                          Display shows "m" for personal message. "W" for winlink info. "M" for both.
  Message is cleared when you cycled through the display up to the ((BN)) screen.

  Thomas dl3el's commit messages:
  - include LastMessage in flip pages
    indicate message unread with an "m" between time & uptime
    flag is cleared when all pages have been flipped through and the manual beacon has been sent

  - move display of buildnr to the last butone flip page. Gives us more space for the message "next button will tx beacon"

Signed-off-by: DL3EL <dl3el@darc.de>

Signed-off-by: Thomas Osterried <dl9sau@darc.de>

src/TTGO_T-Beam_LoRa_APRS.ino

@@ -327,6 +327,9 @@ struct LastHeard{
 struct LastHeard LH[MAX_LH];
 
 String RX_RAW_PACKET_LIST[3];
+String LastRXMessage = "";
+String LastRXMessageTimeAndSender = "";
+uint8_t LastRXMessageInfo = 0;  # bitmask: 1 personal aprs text message. 2 winlink message. 3 both. => Display maker: 1: "m", 2: "W", 3: "M"
 
 //byte Variables
 byte  lora_TXStart;          //start of packet data in TXbuff
@@ -1677,13 +1680,22 @@ void fillDisplayLine1(int caller) {
   OledLine1 = String("Up ") + String(s_uptime);
   if (*gps_time_s)
     OledLine1 = String(gps_time_s) + String(" ") + OledLine1;
-  if (winlink_notified != 0L) {
+  if (LastRXMessageInfo == 3) {
+    // winlink and personal message -> "M"
+    OledLine1 += " M";
+  } else if (LastRXMessageInfo == 1) {
+    // personal message -> "m"
+    OledLine1 += " m";
+  } else if (winlink_notified != 0L) {
     if (winlink_notified + 60*60*24*1000L > millis()) {
       // show winlink mail info for max 24h
       OledLine1 += " W";
     } else {
       // reset
       winlink_notified = 0L;
+      // Remove winlink indicator bit
+      if (LastRXMessageInfo & 2)
+        LastRXMessageInfo &= ~2;
     }
   }
 }
@@ -5450,7 +5462,32 @@ String handle_aprs_messsage_addressed_to_us(const char *received_frame) {
         *q = 0;
       enableOled_now(); // enable OLED
       freeze_display = true;
-      writedisplaytext(" ((MSG))","",String(msg_from) + String(": ") + String(header_normal_or_third_party_end + 11+1),"","","");
+      String RXMessageTimeAndSender;
+      if (*gps_time_s)
+        RXMessageTimeAndSender = String(gps_time_s);
+      else
+        RXMessageTimeAndSender = String("@up ") + compute_time_since_received(millis()/1000);
+      RXMessageTimeAndSender = RXMessageTimeAndSender + String(" ") + String(msg_from) + ":";
+      String RXMessage = String(header_normal_or_third_party_end + 11+1);
+      writedisplaytext(" ((MSG))",RXMessageTimeAndSender,RXMessage,"","","");
+      if (RXMessage.indexOf("foobar") > -1 || (add_winlink_notification &&
+          !strncmp(header_normal_or_third_party_start, "WLNK-1", 6) && header_normal_or_third_party_start[6] == '>' &&
+          !strncmp(header_normal_or_third_party_end + 12, "You have ", 9) &&
+              strstr(header_normal_or_third_party_end + 20, " Winlink mail messages pending"))) {
+        // Don't overwrite a friend's nessage with winlinkInfo
+        LastRXMessageInfo |= 2;
+        if (!(LastRXMessageInfo & 1)) {
+          // Store message
+          LastRXMessageTimeAndSender = String(RXMessageTimeAndSender);
+          LastRXMessage = String(RXMessage);
+        }
+        winlink_notified = millis();
+      } else {
+        // Store message
+        LastRXMessageInfo |= 1;
+        LastRXMessageTimeAndSender = String(RXMessageTimeAndSender);
+        LastRXMessage = String(RXMessage);
+      }
 #ifdef ENABLE_WIFI
       // TODO: add message to a new-to-implement web-received-list-for-aps-messages
 #endif
@@ -5471,12 +5508,6 @@ String handle_aprs_messsage_addressed_to_us(const char *received_frame) {
         msg_from[9] = 0;
         answer_message = Tcall + ">" + MY_APRS_DEST_IDENTIFYER + "::" + String(msg_from) + ":ack" + String(q+1);
       }
-      if (add_winlink_notification &&
-          !strncmp(header_normal_or_third_party_start, "WLNK-1", 6) && header_normal_or_third_party_start[6] == '>' &&
-          !strncmp(header_normal_or_third_party_end + 12, "You have ", 9) &&
-              strstr(header_normal_or_third_party_end + 20, " Winlink mail messages pending")) {
-        winlink_notified = millis();
-      }
     }
   }
 
@@ -5721,13 +5752,23 @@ void loop()
             #endif
             if (button_down_count == 1) {
               write_last_heard_calls_with_distance_and_course_to_display();
+            } else if (button_down_count == 2) {
+              writedisplaytext("((MSG))",LastRXMessageTimeAndSender,LastRXMessage,"","","");
             } else if (button_down_count == 2) {
               writedisplaytext("((BN))","","BuildNr:" + buildnr,"by DL9SAU & DL3EL","","");
             } else if (button_down_count < 6) {
               int n = button_down_count-3;
-              writedisplaytext(n == 0 ? "RX raw" : "RX raw-" + String(n+1),n == 2 ? "next press: tx bcn" : "",RX_RAW_PACKET_LIST[n],"","","");
+              writedisplaytext("RX raw-" + String(n+1),"",RX_RAW_PACKET_LIST[n],"","","");
               time_to_refresh = millis() + showRXTime;
             } else if (button_down_count == 6) {
+              writedisplaytext("((BN))","BuildNr:" + buildnr,"by DL9SAU & DL3EL","","next press: tx bcn","or wait ...");
+              // If we cycled through to this last page, we can remove the "new message-indicator"
+              if (LastRXMessageInfo & 2) {
+                // last received was a winlink notification and we just read that message
+                winlink_notified = 0L;
+              }
+              LastRXMessageInfo = 0;
+            } else if (button_down_count == 7) {
               button_down_count = 0;
               if (lora_tx_enabled || aprsis_enabled) {
                 freeze_display = false;