ComboBoxAttachment: Fix an issue where parameter ranges were converted incorrectly

modules/juce_audio_processors/utilities/juce_ParameterAttachments.cpp

@@ -191,6 +191,7 @@ ComboBoxParameterAttachment::ComboBoxParameterAttachment (RangedAudioParameter&
                                                           ComboBox& c,
                                                           UndoManager* um)
     : comboBox (c),
+      storedParameter (param),
       attachment (param, [this] (float f) { setValue (f); }, um)
 {
     sendInitialUpdate();
@@ -209,7 +210,8 @@ void ComboBoxParameterAttachment::sendInitialUpdate()
 
 void ComboBoxParameterAttachment::setValue (float newValue)
 {
-    const auto index = roundToInt (newValue);
+    const auto normValue = storedParameter.convertTo0to1 (newValue);
+    const auto index = roundToInt (normValue * (float) (comboBox.getNumItems() - 1));
 
     if (index == comboBox.getSelectedItemIndex())
         return;
@@ -223,7 +225,12 @@ void ComboBoxParameterAttachment::comboBoxChanged (ComboBox*)
     if (ignoreCallbacks)
         return;
 
-    attachment.setValueAsCompleteGesture ((float) comboBox.getSelectedItemIndex());
+    const auto numItems = comboBox.getNumItems();
+    const auto selected = (float) comboBox.getSelectedItemIndex();
+    const auto newValue = numItems > 1 ? selected / (float) (numItems - 1)
+                                       : 0.0f;
+
+    attachment.setValueAsCompleteGesture (storedParameter.convertFrom0to1 (newValue));
 }
 
 //==============================================================================

modules/juce_audio_processors/utilities/juce_ParameterAttachments.h

@@ -203,6 +203,7 @@ private:
     void comboBoxChanged (ComboBox*) override;
 
     ComboBox& comboBox;
+    RangedAudioParameter& storedParameter;
     ParameterAttachment attachment;
     bool ignoreCallbacks = false;
 };