Support factory programs in VST3 hosting

modules/juce_audio_processors/format_types/juce_VST3PluginFormat.cpp

@@ -694,8 +694,8 @@ public:
 
     tresult PLUGIN_API notifyProgramListChange (Vst::ProgramListID, Steinberg::int32) override
     {
-        jassertfalse;
-        return kResultFalse;
+        owner->syncProgramNames();
+        return kResultTrue;
     }
 
     //==============================================================================
@@ -1594,6 +1594,7 @@ public:
       : module (handle),
         numInputAudioBusses (0),
         numOutputAudioBusses (0),
+        programParameterID (-1),
         inputParameterChanges (new ParamValueQueueList()),
         outputParameterChanges (new ParamValueQueueList()),
         midiInputs (new MidiEventList()),
@@ -1663,6 +1664,7 @@ public:
         grabInformationObjects();
         synchroniseStates();
         interconnectComponentAndController();
+        syncProgramNames();
         setupIO();
         return true;
     }
@@ -1951,16 +1953,22 @@ public:
     }
 
     //==============================================================================
-    int getNumPrograms() override                        { return getProgramListInfo (0).programCount; }
-    int getCurrentProgram() override                     { return 0; }
-    void setCurrentProgram (int) override                {}
+    int getNumPrograms() override                        { return programNames.size(); }
+    const String getProgramName (int index) override     { return programNames[index]; }
+    int getCurrentProgram() override                     { return jmax (0, (int) editController->getParamNormalized (programParameterID) * (programNames.size() - 1)); }
     void changeProgramName (int, const String&) override {}
 
-    const String getProgramName (int index) override
+    void setCurrentProgram (int program) override
     {
-        Vst::String128 result;
-        unitInfo->getProgramName (getProgramListInfo (0).id, index, result);
-        return toString (result);
+        if (programNames.size() > 0 && editController != nullptr)
+        {
+            Vst::ParamValue value =
+                static_cast<Vst::ParamValue> (program) / static_cast<Vst::ParamValue> (programNames.size());
+
+            editController->setParamNormalized (programParameterID, value);
+            Steinberg::int32 index;
+            inputParameterChanges->addParameterData (programParameterID, index)->addPoint (0, value, index);
+        }
     }
 
     //==============================================================================
@@ -2167,6 +2175,9 @@ private:
     VST3FloatAndDoubleBusMapComposite inputBusMap, outputBusMap;
     Array<Vst::AudioBusBuffers> inputBusses, outputBusses;
 
+    StringArray programNames;
+    Vst::ParamID programParameterID;
+
     //==============================================================================
     template <typename Type>
     static void appendStateFrom (XmlElement& head, ComSmartPtr<Type>& object, const String& identifier)
@@ -2453,6 +2464,82 @@ private:
         return paramInfo;
     }
 
+    void syncProgramNames ()
+    {
+        programNames.clear();
+
+        if (processor == nullptr || editController == nullptr)
+            return;
+
+        Vst::UnitID programUnitID;
+        int stepCount;
+        Vst::ParameterInfo paramInfo = { 0 };
+
+        {
+            int idx, num = editController->getParameterCount();
+            for (idx = 0; idx < num; ++idx)
+                if (editController->getParameterInfo (idx, paramInfo) == kResultOk
+                     && (paramInfo.flags & Steinberg::Vst::ParameterInfo::kIsProgramChange) != 0)
+                    break;
+
+            if (idx >= num) return;
+
+            programParameterID = paramInfo.id;
+            programUnitID = paramInfo.unitId;
+            stepCount = paramInfo.stepCount;
+        }
+
+        if (unitInfo != nullptr)
+        {
+            Vst::UnitInfo info = { 0 };
+            const int unitCount = unitInfo->getUnitCount();
+
+            for (int idx = 0; idx < unitCount; ++idx)
+            {
+                if (unitInfo->getUnitInfo(idx, info) == kResultOk
+                      && info.id == programUnitID)
+                {
+                    const int programListCount = unitInfo->getProgramListCount();
+
+                    for (int j = 0; j < programListCount; ++j)
+                    {
+                        Vst::ProgramListInfo programListInfo = { 0 };
+
+                        if (unitInfo->getProgramListInfo (j, programListInfo) == kResultOk
+                              && programListInfo.id == info.programListId)
+                        {
+                            Vst::String128 name;
+
+                            for (int k = 0; k < programListInfo.programCount; ++k)
+                                if (unitInfo->getProgramName (programListInfo.id, k, name) == kResultOk)
+                                    programNames.add (toString (name));
+
+                            return;
+                        }
+
+                        break;
+                    }
+
+                    break;
+                }
+            }
+
+        }
+
+        if (editController != nullptr
+               && paramInfo.stepCount > 0)
+        {
+            const int numPrograms = paramInfo.stepCount + 1;
+            for (int i = 0; i < numPrograms; ++i)
+            {
+                Vst::String128 programName;
+                Vst::ParamValue valueNormalized = static_cast<Vst::ParamValue> (i) / static_cast<Vst::ParamValue> (paramInfo.stepCount);
+                if (editController->getParamStringByValue (paramInfo.id, valueNormalized, programName) == kResultOk)
+                    programNames.add (toString (programName));
+            }
+        }
+    }
+
     JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (VST3PluginInstance)
 };