Implemented Serializable for TIA inptx registers (LatchedInput

and PaddleReader).  For now, PaddleReader is stubbed out, since
it needs to save double values and Serializer can't do that yet.

Fixed bug in Ball, Background and Playfield serialization; they
were correctly saving data, but returning false (indicating failure).

src/emucore/StateManager.cxx

@@ -28,7 +28,7 @@
 
 #include "StateManager.hxx"
 
-#define STATE_HEADER "04090100state"
+#define STATE_HEADER "04090200state"
 #define MOVIE_HEADER "03030000movie"
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

src/emucore/tia/Background.cxx

@@ -75,7 +75,7 @@ bool Background::save(Serializer& out) const
     return false;
   }
 
-  return false;
+  return true;
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
@@ -99,5 +99,5 @@ bool Background::load(Serializer& in)
     return false;
   }
 
-  return false;
+  return true;
 }

src/emucore/tia/Ball.cxx

@@ -243,7 +243,7 @@ bool Ball::save(Serializer& out) const
     return false;
   }
 
-  return false;
+  return true;
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
@@ -288,5 +288,5 @@ bool Ball::load(Serializer& in)
     return false;
   }
 
-  return false;
+  return true;
 }

src/emucore/tia/LatchedInput.cxx

@@ -53,3 +53,42 @@ uInt8 LatchedInput::inpt(bool pinState)
 
   return value;
 }
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+bool LatchedInput::save(Serializer& out) const
+{
+  try
+  {
+    out.putString(name());
+
+    out.putBool(myModeLatched);
+    out.putByte(myLatchedValue);
+  }
+  catch(...)
+  {
+    cerr << "ERROR: TIA_LatchedInput::save" << endl;
+    return false;
+  }
+
+  return true;
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+bool LatchedInput::load(Serializer& in)
+{
+  try
+  {
+    if(in.getString() != name())
+      return false;
+
+    myModeLatched = in.getBool();
+    myLatchedValue = in.getByte();
+  }
+  catch(...)
+  {
+    cerr << "ERROR: TIA_LatchedInput::load" << endl;
+    return false;
+  }
+
+  return true;
+}

src/emucore/tia/LatchedInput.hxx

@@ -19,8 +19,9 @@
 #define TIA_LATCHED_INPUT
 
 #include "bspf.hxx"
+#include "Serializable.hxx"
 
-class LatchedInput
+class LatchedInput : public Serializable
 {
   public:
     LatchedInput();
@@ -34,6 +35,13 @@ class LatchedInput
 
     uInt8 inpt(bool pinState);
 
+    /**
+      Serializable methods (see that class for more information).
+    */
+    bool save(Serializer& out) const override;
+    bool load(Serializer& in) override;
+    string name() const override { return "TIA_PADDLE_READER"; }
+
   private:
 
     bool myModeLatched;

src/emucore/tia/PaddleReader.cxx

@@ -103,3 +103,42 @@ void PaddleReader::updateCharge(double timestamp)
 
   myTimestamp = timestamp;
 }
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+// TODO: implement this once the class is finalized
+bool PaddleReader::save(Serializer& out) const
+{
+  try
+  {
+    out.putString(name());
+
+    // TODO - save instance variables
+  }
+  catch(...)
+  {
+    cerr << "ERROR: TIA_PaddleReader::save" << endl;
+    return false;
+  }
+
+  return false;
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+// TODO: implement this once the class is finalized
+bool PaddleReader::load(Serializer& in)
+{
+  try
+  {
+    if(in.getString() != name())
+      return false;
+
+    // TODO - load instance variables
+  }
+  catch(...)
+  {
+    cerr << "ERROR: TIA_PaddleReader::load" << endl;
+    return false;
+  }
+
+  return false;
+}

src/emucore/tia/PaddleReader.hxx

@@ -20,8 +20,9 @@
 
 #include "bspf.hxx"
 #include "TvMode.hxx"
+#include "Serializable.hxx"
 
-class PaddleReader
+class PaddleReader : public Serializable
 {
   public:
 
@@ -38,6 +39,13 @@ class PaddleReader
 
     void update(double value, double timestamp, TvMode tvMode);
 
+    /**
+      Serializable methods (see that class for more information).
+    */
+    bool save(Serializer& out) const override;
+    bool load(Serializer& in) override;
+    string name() const override { return "TIA_PADDLE_READER"; }
+
   private:
 
     void setTvMode(TvMode mode);
@@ -58,7 +66,6 @@ class PaddleReader
     bool myIsDumped;
 
   private:
-
     PaddleReader(const PaddleReader&) = delete;
     PaddleReader(PaddleReader&&) = delete;
     PaddleReader& operator=(const PaddleReader&) = delete;

src/emucore/tia/Playfield.cxx

@@ -232,7 +232,7 @@ bool Playfield::save(Serializer& out) const
     return false;
   }
 
-  return false;
+  return true;
 }
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
@@ -279,5 +279,5 @@ bool Playfield::load(Serializer& in)
     return false;
   }
 
-  return false;
+  return true;
 }

src/emucore/tia/TIA.cxx

@@ -207,6 +207,14 @@ bool TIA::save(Serializer& out) const
     if(!myPlayer1.save(out))    return false;
     if(!myBall.save(out))       return false;
 
+    // Save dumped input ports
+    for (const PaddleReader& paddleReader : myPaddleReaders)
+      if(!paddleReader.save(out)) return false;
+
+    // Save latched input ports
+    if(!myInput0.save(out)) return false;
+    if(!myInput1.save(out)) return false;
+
     // Save the sound sample stuff ...
     mySound.save(out);
   }
@@ -237,6 +245,14 @@ bool TIA::load(Serializer& in)
     if(!myPlayer0.load(in))    return false;
     if(!myPlayer1.load(in))    return false;
     if(!myBall.load(in))       return false;
+
+    // Load dumped input ports
+    for (PaddleReader& paddleReader : myPaddleReaders)
+      if(!paddleReader.load(in)) return false;
+
+    // Load latched input ports
+    if(!myInput0.load(in)) return false;
+    if(!myInput1.load(in)) return false;
   }
   catch(...)
   {