AUDIO: Change several fake MidiDrivers to MidiDriver_BASE subclasses

Many engines follow the advice in audio/midiparser.h and create a
"pseudo-MidiDriver" subclass. But MidiParser really only needs a tiny
subset of the MidiDriver capabilities, namely those found in
MidiDriver_BASE. So we try to subclass from that whenever possible; this
allows us to remove many stub methods, and enables further future
simplifications.

2 files changed, 2 insertions, 20 deletions

diff --git a/engines/parallaction/sound_br.cpp b/engines/parallaction/sound_br.cpp
index 80bd95779d..b74a584b2c 100644
--- a/engines/parallaction/sound_br.cpp
+++ b/engines/parallaction/sound_br.cpp
@@ -201,7 +201,7 @@ MidiParser *createParser_MSC() {
 }
 
 
-class MidiPlayer_MSC : public MidiDriver {
+class MidiPlayer_MSC : public MidiDriver_BASE {
 public:
 
 	enum {
@@ -222,14 +222,9 @@ public:
 
 	// MidiDriver interface
 	int open();
-	bool isOpen() const;
 	void close();
 	void send(uint32 b);
 	void metaEvent(byte type, byte *data, uint16 length);
-	void setTimerCallback(void *timerParam, void (*timerProc)(void *)) { }
-	uint32 getBaseTempo() { return _driver ? _driver->getBaseTempo() : 0; }
-	MidiChannel *allocateChannel() { return 0; }
-	MidiChannel *getPercussionChannel() { return 0; }
 
 private:
 
@@ -342,10 +337,6 @@ int MidiPlayer_MSC::open() {
 	return ret;
 }
 
-bool MidiPlayer_MSC::isOpen() const {
-	return _driver && _driver->isOpen();
-}
-
 void MidiPlayer_MSC::close() {
 	stop();
 
diff --git a/engines/parallaction/sound_ns.cpp b/engines/parallaction/sound_ns.cpp
index aeb934fd8b..6d80b5dbc1 100644
--- a/engines/parallaction/sound_ns.cpp
+++ b/engines/parallaction/sound_ns.cpp
@@ -38,7 +38,7 @@
 
 namespace Parallaction {
 
-class MidiPlayer : public MidiDriver {
+class MidiPlayer : public MidiDriver_BASE {
 public:
 
 	enum {
@@ -59,14 +59,9 @@ public:
 
 	// MidiDriver interface
 	int open();
-	bool isOpen() const;
 	void close();
 	void send(uint32 b);
 	void metaEvent(byte type, byte *data, uint16 length);
-	void setTimerCallback(void *timerParam, void (*timerProc)(void *)) { }
-	uint32 getBaseTempo() { return _driver ? _driver->getBaseTempo() : 0; }
-	MidiChannel *allocateChannel() { return 0; }
-	MidiChannel *getPercussionChannel() { return 0; }
 
 private:
 
@@ -177,10 +172,6 @@ int MidiPlayer::open() {
 	return ret;
 }
 
-bool MidiPlayer::isOpen() const {
-	return _driver && _driver->isOpen();
-}
-
 void MidiPlayer::close() {
 	stop();