From 5872659ff288f752fafe1640a819bf39ed2e27d5 Mon Sep 17 00:00:00 2001
From: Asbelos <asbelos@btinternet.com>
Date: Thu, 18 Jun 2020 19:36:37 +0100
Subject: [PATCH] Command Filter and some extra APIs.

---
 CVReader.ino    |  9 +++++++++
 DCC.cpp         |  8 ++++++++
 DCC.h           |  7 ++++++-
 DCCEXParser.cpp | 16 ++++++++++++----
 DCCEXParser.h   |  8 +++++++-
 5 files changed, 42 insertions(+), 6 deletions(-)

diff --git a/CVReader.ino b/CVReader.ino
index bb676a1..1dda384 100644
--- a/CVReader.ino
+++ b/CVReader.ino
@@ -18,6 +18,14 @@ void myCallback(int result) {
   DIAG(F("\n getting Loco Id callback result=%d"),result); 
 }
 
+
+void myFilter(Stream & stream, byte & opcode, byte & paramCount, int p[]) {
+    if (opcode=='T') {
+      DIAG(F("\nStop messing with Turnouts!"));
+      opcode=0; // tell parssr to ignore it   
+    }
+}
+
 DCCEXParser  serialParser;
 
 void setup() {
@@ -28,6 +36,7 @@ void setup() {
    DCC::getLocoId(myCallback); // myCallback will be called with the result 
    DIAG(F("\n===== DCC::getLocoId has returned, but wont be executed until we are in loop() ======\n"));
    DIAG(F("\nReady for JMRI commands\n"));
+   DCCEXParser::setFilter(myFilter);
 }
 
 void loop() {      
diff --git a/DCC.cpp b/DCC.cpp
index 32c131f..67e1857 100644
--- a/DCC.cpp
+++ b/DCC.cpp
@@ -234,6 +234,14 @@ void DCC::getLocoId(ACK_CALLBACK callback) {
   ackManagerSetup(0,0, LOCO_ID_PROG, callback);
 }
 
+void DCC::forgetLoco(int cab) {  // removes any speed reminders for this loco  
+  for (int i=0;i<MAX_LOCOS;i++) if (speedTable[i].loco=cab) speedTable[i].loco=0;
+}
+void DCC::forgetAllLocos() {  // removes all speed reminders
+  for (int i=0;i<MAX_LOCOS;i++) speedTable[i].loco=0;  
+}
+  
+
 void DCC::loop()  {
   DCCWaveform::loop(); // power overload checks
   ackManagerLoop();
diff --git a/DCC.h b/DCC.h
index 80b45fb..7265966 100644
--- a/DCC.h
+++ b/DCC.h
@@ -51,6 +51,10 @@ class DCC {
   
   static void getLocoId(ACK_CALLBACK callback);
 
+  // Enhanced API functions
+  static void forgetLoco(int cab);  // removes any speed reminders for this loco  
+  static void forgetAllLocos();  // removes all speed reminders
+    
 private: 
   struct LOCO {
      int loco;
@@ -62,7 +66,8 @@ private:
   static LOCO speedTable[MAX_LOCOS];
   static byte cv1(byte opcode, int cv);
   static byte cv2(int cv);
-
+  
+  
 
 // ACK MANAGER
   static ackOp  const * ackManagerProg;
diff --git a/DCCEXParser.cpp b/DCCEXParser.cpp
index f456b5f..96bb80a 100644
--- a/DCCEXParser.cpp
+++ b/DCCEXParser.cpp
@@ -94,18 +94,26 @@ void DCCEXParser::loop(Stream & stream) {
       return parameterCount;
 }
 
+FILTER_CALLBACK  DCCEXParser::filterCallback=0;
+void DCCEXParser::setFilter(FILTER_CALLBACK filter) {
+  filterCallback=filter;  
+}
+   
 // See documentation on DCC class for info on this section
 void DCCEXParser::parse(Print & stream, const char *com) {
     DIAG(F("\nPARSING:%s\n"),com);
     (void) EEPROM; // tell compiler not to warn thi is unused
     int p[MAX_PARAMS];  
-    int params=splitValues(p, com); 
+    byte params=splitValues(p, com); 
 
     if (com[0]=='<') com++;
-    
+    byte opcode=com[0];
+     
+    if (filterCallback)  filterCallback(stream,opcode,params,p);
+     
     // Functions return from this switch if complete, break from switch implies error <X> to send
-    switch(com[0]) {
-    
+    switch(opcode) {
+    case '\0': return;    // filterCallback asked us to ignore 
     case 't':       // THROTTLE <t REGISTER CAB SPEED DIRECTION>
         DCC::setThrottle(p[1],p[2],p[3]);
         StringFormatter::send(stream,F("<T %d %d %d>"), p[0], p[2],p[3]);
diff --git a/DCCEXParser.h b/DCCEXParser.h
index 23c1b47..6246936 100644
--- a/DCCEXParser.h
+++ b/DCCEXParser.h
@@ -1,15 +1,20 @@
 #ifndef DCCEXParser_h
 #define DCCEXParser_h
 #include <Arduino.h>
+
+typedef void (*FILTER_CALLBACK)(Print & stream, byte & opcode, byte & paramCount, int p[]);
+
 struct DCCEXParser
 {
    DCCEXParser();
    void loop(Stream & pstream);
    void parse(Print & stream, const char * command);
    void flush();
+   static void setFilter(FILTER_CALLBACK filter);
+   static const int MAX_PARAMS=10;  // Must not exceed this
+ 
    private:
   
-    static const int MAX_PARAMS=10;  // longest command sent in
     static const int MAX_BUFFER=50;  // longest command sent in
      byte  bufferLength=0;
      bool  inCommandPayload=false;
@@ -28,6 +33,7 @@ struct DCCEXParser
     static void callback_W(int result);
     static void callback_B(int result);        
     static void callback_R(int result);
+    static FILTER_CALLBACK  filterCallback;
   
 };