Allow subclasses to refuse particular (vid, pid) pairs.

stepmania/src/archutils/Darwin/HIDDevice.cpp

@@ -47,10 +47,6 @@ bool HIDDevice::Open( io_object_t device )
 	
 	object = CFDictionaryGetValue( properties, CFSTR(kIOHIDProductKey) );
 	
-	if( object && CFGetTypeID(object) == CFStringGetTypeID() )
-		m_sDescription = CFStringGetCStringPtr( CFStringRef(object), CFStringGetSystemEncoding() );
-	if( m_sDescription == "" )
-	{
 	CFTypeRef vidRef = CFDictionaryGetValue( properties, CFSTR(kIOHIDVendorIDKey) );
 	CFTypeRef pidRef = CFDictionaryGetValue( properties, CFSTR(kIOHIDProductIDKey) );
 	int vid, pid;
@@ -59,9 +55,18 @@ bool HIDDevice::Open( io_object_t device )
 		vid = 0;
 	if( pidRef && !IntValue(pidRef, pid) )
 		pid = 0;
-		m_sDescription = ssprintf( "%04x:%04x", vid, pid );
+	
+	if( !SupportsVidPid(vid, pid) )
+	{
+		CFRelease( properties );
+		return false;
 	}
 	
+	if( object && CFGetTypeID(object) == CFStringGetTypeID() )
+		m_sDescription = CFStringGetCStringPtr( CFStringRef(object), CFStringGetSystemEncoding() );
+	if( m_sDescription == "" )
+		m_sDescription = ssprintf( "%04x:%04x", vid, pid );
+	
 	object = CFDictionaryGetValue( properties, CFSTR(kIOHIDElementKey) );
 	if ( !object || CFGetTypeID(object) != CFArrayGetTypeID() )
 	{

stepmania/src/archutils/Darwin/HIDDevice.h

@@ -72,6 +72,11 @@ protected:
 	 */
 	virtual void Open() = 0;
 	
+	/*
+	 * Optional. Subclasses can return false if they do not support the (vid, pid) pair.
+	 */
+	virtual bool SupportsVidPid( int vid, int pid ) { return true; }
+	
 	// This adds the element with the given cookie to the queue to be notified of state changes.
 	inline void AddElementToQueue( int cookie )
 	{