Added a Listener class to MPEZoneLayout.

modules/juce_audio_basics/mpe/juce_MPEZoneLayout.cpp

@@ -26,6 +26,17 @@ MPEZoneLayout::MPEZoneLayout() noexcept
 {
 }
 
+MPEZoneLayout::MPEZoneLayout (const MPEZoneLayout& other)
+    : zones (other.zones)
+{
+}
+
+MPEZoneLayout& MPEZoneLayout::operator= (const MPEZoneLayout& other)
+{
+    zones = other.zones;
+    return *this;
+}
+
 //==============================================================================
 bool MPEZoneLayout::addZone (MPEZone newZone)
 {
@@ -46,6 +57,7 @@ bool MPEZoneLayout::addZone (MPEZone newZone)
     }
 
     zones.add (newZone);
+    listeners.call (&MPEZoneLayout::Listener::zoneLayoutChanged, *this);
     return noOtherZonesModified;
 }
 
@@ -66,6 +78,7 @@ MPEZone* MPEZoneLayout::getZoneByIndex (int index) const noexcept
 void MPEZoneLayout::clearAllZones()
 {
     zones.clear();
+    listeners.call (&MPEZoneLayout::Listener::zoneLayoutChanged, *this);
 }
 
 //==============================================================================
@@ -106,12 +119,20 @@ void MPEZoneLayout::processPitchbendRangeRpnMessage (MidiRPNMessage rpn)
 {
     if (MPEZone* zone = getZoneByFirstNoteChannel (rpn.channel))
     {
-        zone->setPerNotePitchbendRange (rpn.value);
-        return;
+        if (zone->getPerNotePitchbendRange() != rpn.value)
+        {
+            zone->setPerNotePitchbendRange (rpn.value);
+            listeners.call (&MPEZoneLayout::Listener::zoneLayoutChanged, *this);
+        }
+    }
+    else if (MPEZone* zone = getZoneByMasterChannel (rpn.channel))
+    {
+        if (zone->getMasterPitchbendRange() != rpn.value)
+        {
+            zone->setMasterPitchbendRange (rpn.value);
+            listeners.call (&MPEZoneLayout::Listener::zoneLayoutChanged, *this);
+        }
     }
-
-    if (MPEZone* zone = getZoneByMasterChannel (rpn.channel))
-        zone->setMasterPitchbendRange (rpn.value);
 }
 
 //==============================================================================
@@ -162,6 +183,25 @@ MPEZone* MPEZoneLayout::getZoneByNoteChannel (int channel) const noexcept
     return nullptr;
 }
 
+//==============================================================================
+void MPEZoneLayout::addListener (Listener* const listenerToAdd) noexcept
+{
+    listeners.add (listenerToAdd);
+}
+
+void MPEZoneLayout::removeListener (Listener* const listenerToRemove) noexcept
+{
+    listeners.remove (listenerToRemove);
+}
+
+MPEZoneLayout::Listener::Listener()
+{
+}
+
+MPEZoneLayout::Listener::~Listener()
+{
+}
+
 //==============================================================================
 //==============================================================================
 #if JUCE_UNIT_TESTS

modules/juce_audio_basics/mpe/juce_MPEZoneLayout.h

@@ -47,6 +47,16 @@ public:
     */
     MPEZoneLayout() noexcept;
 
+    /** Copy constuctor.
+        This will not copy the listeners registered to the MPEZoneLayout.
+    */
+    MPEZoneLayout (const MPEZoneLayout& other);
+
+    /** Copy assignment operator.
+        This will not copy the listeners registered to the MPEZoneLayout.
+    */
+    MPEZoneLayout& operator= (const MPEZoneLayout& other);
+
     /** Adds a new MPE zone to the layout.
 
         @param newZone  The zone to add.
@@ -115,10 +125,38 @@ public:
     */
     MPEZone* getZoneByNoteChannel (int midiChannel) const noexcept;
 
+    //==========================================================================
+    /** Listener class. Derive from this class to allow your class to be
+        notified about changes to the zone layout.
+    */
+    class Listener
+    {
+    public:
+        /** Constructor. */
+        Listener();
+
+        /** Destructor. */
+        virtual ~Listener();
+
+        /** Implement this callback to be notified about any changes to this
+            MPEZoneLayout. Will be called whenever a zone is added, zones are
+            removed, or any zone's master or note pitchbend ranges change.
+        */
+        virtual void zoneLayoutChanged (const MPEZoneLayout& layout) = 0;
+    };
+
+    //==========================================================================
+    /** Adds a listener. */
+    void addListener (Listener* const listenerToAdd) noexcept;
+
+    /** Removes a listener. */
+    void removeListener (Listener* const listenerToRemove) noexcept;
+
 private:
     //==========================================================================
     Array<MPEZone> zones;
     MidiRPNDetector rpnDetector;
+    ListenerList<Listener> listeners;
 
     void processRpnMessage (MidiRPNMessage);
     void processZoneLayoutRpnMessage (MidiRPNMessage);