Instrument: introduced flags to replace virtual property getters

There'll be more and more flags for instruments. Handling them using
virtual and overloaded getter functions doesn't scale well and adds
unneccessary overhead.

include/Instrument.h

@@ -44,6 +44,16 @@ class track;
 class EXPORT Instrument : public Plugin
 {
 public:
+	enum Flag
+	{
+		NoFlags = 0x00,
+		IsSingleStreamed = 0x01,	/*! Instrument provides a single audio stream for all notes */
+		IsMidiBased = 0x02,			/*! Instrument is controlled by MIDI events rather than NotePlayHandles */
+		IsNotBendable = 0x04,		/*! Instrument can't react to pitch bend changes */
+	};
+
+	Q_DECLARE_FLAGS(Flags, Flag);
+
 	Instrument( InstrumentTrack * _instrument_track,
 					const Descriptor * _descriptor );
 	virtual ~Instrument();
@@ -84,17 +94,9 @@ public:
 		return 0;
 	}
 
-	// return false if instrument is not bendable
-	inline virtual bool isBendable() const
+	virtual Flags flags() const
 	{
-		return true;
-	}
-
-	// return true if instruments reacts to MIDI events passed to
-	// handleMidiEvent() rather than playNote() & Co
-	inline virtual bool isMidiBased() const
-	{
-		return false;
+		return NoFlags;
 	}
 
 	// sub-classes can re-implement this for receiving all incoming
@@ -135,4 +137,6 @@ private:
 
 } ;
 
+Q_DECLARE_OPERATORS_FOR_FLAGS(Instrument::Flags)
+
 #endif