Fix event type and parameter type confusion

I'm not sure if this is really the best way to do event types (should it
just be a completely static enum in evoral, or completely dynamic and
provided by the type map, or a mix like currently?), but previously the
event type was frequently set to either total garbage, or parameter
types, which are a different thing.

This fixes all those cases, and makes Evoral::EventType an enum so the
compiler will warn about implicit conversions from int.

5 files changed, 34 insertions, 18 deletions

diff --git a/libs/evoral/evoral/Event.hpp b/libs/evoral/evoral/Event.hpp
index 526513b3fe..696fb995ab 100644
--- a/libs/evoral/evoral/Event.hpp
+++ b/libs/evoral/evoral/Event.hpp
@@ -48,7 +48,7 @@ template<typename Time>
 class LIBEVORAL_API Event {
 public:
 #ifdef EVORAL_EVENT_ALLOC
-	Event(EventType type=0, Time time=Time(), uint32_t size=0, uint8_t* buf=NULL, bool alloc=false);
+	Event(EventType type=NO_EVENT, Time time=Time(), uint32_t size=0, uint8_t* buf=NULL, bool alloc=false);
 
 	Event(EventType type, Time time, uint32_t size, const uint8_t* buf);
 
@@ -108,7 +108,7 @@ public:
 	}
 
 	inline void clear() {
-		_type          = 0;
+		_type          = NO_EVENT;
 		_original_time = Time();
 		_nominal_time  = Time();
 		_size          = 0;
diff --git a/libs/evoral/evoral/Parameter.hpp b/libs/evoral/evoral/Parameter.hpp
index 1412699b4d..2614a03d86 100644
--- a/libs/evoral/evoral/Parameter.hpp
+++ b/libs/evoral/evoral/Parameter.hpp
@@ -25,6 +25,7 @@
 #include <boost/shared_ptr.hpp>
 
 #include "evoral/visibility.h"
+#include "evoral/types.hpp"
 
 namespace Evoral {
 
@@ -40,13 +41,13 @@ namespace Evoral {
 class LIBEVORAL_API Parameter
 {
 public:
-	inline Parameter(uint32_t type, uint8_t channel=0, uint32_t id=0)
+	inline Parameter(ParameterType type, uint8_t channel=0, uint32_t id=0)
 		: _type(type), _id(id), _channel(channel)
 	{}
 
-	inline uint32_t type()    const { return _type; }
-	inline uint8_t  channel() const { return _channel; }
-	inline uint32_t id()      const { return _id; }
+	inline ParameterType type()    const { return _type; }
+	inline uint8_t       channel() const { return _channel; }
+	inline uint32_t      id()      const { return _id; }
 
 	/** Equivalence operator
 	 * It is obvious from the definition that this operator
@@ -80,9 +81,9 @@ public:
 	inline operator bool() const { return (_type != 0); }
 
 private:
-	uint32_t _type;
-	uint32_t _id;
-	uint8_t  _channel;
+	ParameterType _type;
+	uint32_t      _id;
+	uint8_t       _channel;
 };
 
 } // namespace Evoral
diff --git a/libs/evoral/evoral/PatchChange.hpp b/libs/evoral/evoral/PatchChange.hpp
index a775a72cc3..90d3dba732 100644
--- a/libs/evoral/evoral/PatchChange.hpp
+++ b/libs/evoral/evoral/PatchChange.hpp
@@ -39,9 +39,9 @@ public:
 	 *  @param b Bank number (counted from 0, 14-bit).
 	 */
 	PatchChange (Time t, uint8_t c, uint8_t p, int b)
-		: _bank_change_msb (0, t, 3, 0, true)
-		, _bank_change_lsb (0, t, 3, 0, true)
-		, _program_change (0, t, 2, 0, true)
+		: _bank_change_msb (MIDI_EVENT, t, 3, 0, true)
+		, _bank_change_lsb (MIDI_EVENT, t, 3, 0, true)
+		, _program_change (MIDI_EVENT, t, 2, 0, true)
 	{
 		_bank_change_msb.buffer()[0] = MIDI_CMD_CONTROL | c;
 		_bank_change_msb.buffer()[1] = MIDI_CTL_MSB_BANK;
diff --git a/libs/evoral/evoral/TypeMap.hpp b/libs/evoral/evoral/TypeMap.hpp
index d09439daa6..0ebc81370b 100644
--- a/libs/evoral/evoral/TypeMap.hpp
+++ b/libs/evoral/evoral/TypeMap.hpp
@@ -24,6 +24,7 @@
 #include <string>
 
 #include "evoral/visibility.h"
+#include "evoral/types.hpp"
 
 namespace Evoral {
 
@@ -47,9 +48,8 @@ public:
 	 */
 	virtual uint8_t parameter_midi_type(const Parameter& param) const = 0;
 
-	/** The type ID for a MIDI event with the given status byte
-	 */
-	virtual uint32_t midi_event_type(uint8_t status) const = 0;
+	/** The parameter type for the given MIDI event. */
+	virtual ParameterType midi_parameter_type(const uint8_t* buf, uint32_t len) const = 0;
 
 	/** Return the description of a parameter. */
 	virtual ParameterDescriptor descriptor(const Parameter& param) const = 0;
diff --git a/libs/evoral/evoral/types.hpp b/libs/evoral/evoral/types.hpp
index a5d4a8ca1e..72b95f8460 100644
--- a/libs/evoral/evoral/types.hpp
+++ b/libs/evoral/evoral/types.hpp
@@ -1,5 +1,5 @@
 /* This file is part of Evoral.
- * Copyright (C) 2008 David Robillard <http://drobilla.net>
+ * Copyright (C) 2008-2016 David Robillard <http://drobilla.net>
  * Copyright (C) 2000-2008 Paul Davis
  *
  * Evoral is free software; you can redistribute it and/or modify it under the
@@ -37,8 +37,23 @@ namespace Evoral {
 */
 typedef int32_t event_id_t;
 
-/** Type of an event (opaque, mapped by application) */
-typedef uint32_t EventType;
+/** Type of an event (opaque, mapped by application, e.g. MIDI).
+ *
+ * Event types are really an arbitrary integer provided by the type map, and it
+ * is safe to use values not in this enum, but this enum exists so the compiler
+ * can catch mistakes like setting the event type to a MIDI status byte.  Event
+ * types come from the type map and describe a format/protocol like MIDI, and
+ * must not be confused with the payload (such as a note on or CC change).
+ * There is a static value for MIDI as this type is handled specially by
+ * various parts of Evoral.
+ */
+enum EventType {
+	NO_EVENT,
+	MIDI_EVENT
+};
+
+/** Type of a parameter (opaque, mapped by application, e.g. gain) */
+typedef uint32_t ParameterType;
 
 class Beats;