From 71823a3259b1d6f9d54347ca35f8178ef4009884 Mon Sep 17 00:00:00 2001
From: jatinchowdhury18 <jatinchowdhury18@gmail.com>
Date: Sun, 26 Nov 2023 14:41:35 -0700
Subject: [PATCH] Only send parameter gestures if a parameter is connected to a
 juce::AudioProcessor (#471)

* Only send parameter gestures if a parameter is connected to a juce::AudioProcessor

* Add DummyPluginState

* Fixing shadow warning

* More shadow fixes
---
 .../Backend/chowdsp_PluginState.h                 | 15 ++++++++++++++-
 .../Backend/chowdsp_PluginStateImpl.cpp           |  4 ++--
 .../Backend/chowdsp_PluginStateImpl.h             |  2 +-
 .../Frontend/chowdsp_ParameterAttachment.cpp      |  9 +++++----
 .../Frontend/chowdsp_ParameterAttachment.h        |  1 +
 5 files changed, 23 insertions(+), 8 deletions(-)

diff --git a/modules/plugin/chowdsp_plugin_state/Backend/chowdsp_PluginState.h b/modules/plugin/chowdsp_plugin_state/Backend/chowdsp_PluginState.h
index 7f86bdd37..7333a4230 100644
--- a/modules/plugin/chowdsp_plugin_state/Backend/chowdsp_PluginState.h
+++ b/modules/plugin/chowdsp_plugin_state/Backend/chowdsp_PluginState.h
@@ -17,10 +17,11 @@ class PluginState
 
     /** Initialises the plugin state with a given set of parameters. */
     void initialise (ParamHolder& parameters,
-                     juce::AudioProcessor* processor = nullptr,
+                     juce::AudioProcessor* proc = nullptr,
                      juce::UndoManager* um = nullptr)
     {
         params = &parameters;
+        processor = proc;
         undoManager = um;
         listeners.emplace (parameters);
         if (processor != nullptr)
@@ -80,6 +81,7 @@ class PluginState
         mainThreadAction.call (std::forward<Callable> (func), couldBeAudioThread);
     }
 
+    juce::AudioProcessor* processor = nullptr;
     juce::UndoManager* undoManager = nullptr;
 
 private:
@@ -89,4 +91,15 @@ class PluginState
 
     JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (PluginState)
 };
+
+/** A "dummy" plugin state that does absolutely nothing! */
+struct DummyPluginState : PluginState
+{
+    void serialize (juce::MemoryBlock&) const override {}
+    void deserialize (const juce::MemoryBlock&) override {}
+
+    NonParamState non_params {};
+    [[nodiscard]] NonParamState& getNonParameters() override { return non_params; }
+    [[nodiscard]] const NonParamState& getNonParameters() const override { return non_params; }
+};
 } // namespace chowdsp
diff --git a/modules/plugin/chowdsp_plugin_state/Backend/chowdsp_PluginStateImpl.cpp b/modules/plugin/chowdsp_plugin_state/Backend/chowdsp_PluginStateImpl.cpp
index 29b1affc6..acb2d4b09 100644
--- a/modules/plugin/chowdsp_plugin_state/Backend/chowdsp_PluginStateImpl.cpp
+++ b/modules/plugin/chowdsp_plugin_state/Backend/chowdsp_PluginStateImpl.cpp
@@ -7,9 +7,9 @@ PluginStateImpl<ParameterState, NonParameterState, Serializer>::PluginStateImpl
 }
 
 template <typename ParameterState, typename NonParameterState, typename Serializer>
-PluginStateImpl<ParameterState, NonParameterState, Serializer>::PluginStateImpl (juce::AudioProcessor& processor, juce::UndoManager* um)
+PluginStateImpl<ParameterState, NonParameterState, Serializer>::PluginStateImpl (juce::AudioProcessor& proc, juce::UndoManager* um)
 {
-    initialise (params, &processor, um);
+    initialise (params, &proc, um);
 }
 
 template <typename ParameterState, typename NonParameterState, typename Serializer>
diff --git a/modules/plugin/chowdsp_plugin_state/Backend/chowdsp_PluginStateImpl.h b/modules/plugin/chowdsp_plugin_state/Backend/chowdsp_PluginStateImpl.h
index 3f1e26291..76b5ee5fc 100644
--- a/modules/plugin/chowdsp_plugin_state/Backend/chowdsp_PluginStateImpl.h
+++ b/modules/plugin/chowdsp_plugin_state/Backend/chowdsp_PluginStateImpl.h
@@ -20,7 +20,7 @@ class PluginStateImpl : public PluginState
     explicit PluginStateImpl (juce::UndoManager* um = nullptr);
 
     /** Constructs the state and adds all the state parameters to the given processor */
-    explicit PluginStateImpl (juce::AudioProcessor& processor, juce::UndoManager* um = nullptr);
+    explicit PluginStateImpl (juce::AudioProcessor& proc, juce::UndoManager* um = nullptr);
 
     /** Serializes the plugin state to the given MemoryBlock */
     void serialize (juce::MemoryBlock& data) const override;
diff --git a/modules/plugin/chowdsp_plugin_state/Frontend/chowdsp_ParameterAttachment.cpp b/modules/plugin/chowdsp_plugin_state/Frontend/chowdsp_ParameterAttachment.cpp
index bb0fc650d..10f80a2ef 100644
--- a/modules/plugin/chowdsp_plugin_state/Frontend/chowdsp_ParameterAttachment.cpp
+++ b/modules/plugin/chowdsp_plugin_state/Frontend/chowdsp_ParameterAttachment.cpp
@@ -4,10 +4,11 @@ namespace chowdsp
 {
 template <typename Param, typename Callback>
 ParameterAttachment<Param, Callback>::ParameterAttachment (Param& parameter,
-                                                           PluginState& pluginState,
+                                                           PluginState& plugState,
                                                            Callback&& callback)
-    : ParameterAttachment (parameter, pluginState.getParameterListeners(), std::forward<Callback> (callback))
+    : ParameterAttachment (parameter, plugState.getParameterListeners(), std::forward<Callback> (callback))
 {
+    pluginState = &plugState;
 }
 
 template <typename Param, typename Callback>
@@ -28,14 +29,14 @@ ParameterAttachment<Param, Callback>::ParameterAttachment (Param& parameter,
 template <typename Param, typename Callback>
 void ParameterAttachment<Param, Callback>::beginGesture()
 {
-    if (param != nullptr)
+    if (param != nullptr && pluginState != nullptr && pluginState->processor != nullptr)
         param->beginChangeGesture();
 }
 
 template <typename Param, typename Callback>
 void ParameterAttachment<Param, Callback>::endGesture()
 {
-    if (param != nullptr)
+    if (param != nullptr && pluginState != nullptr && pluginState->processor != nullptr)
         param->endChangeGesture();
 }
 
diff --git a/modules/plugin/chowdsp_plugin_state/Frontend/chowdsp_ParameterAttachment.h b/modules/plugin/chowdsp_plugin_state/Frontend/chowdsp_ParameterAttachment.h
index 70a78197d..951502e1b 100644
--- a/modules/plugin/chowdsp_plugin_state/Frontend/chowdsp_ParameterAttachment.h
+++ b/modules/plugin/chowdsp_plugin_state/Frontend/chowdsp_ParameterAttachment.h
@@ -52,6 +52,7 @@ class ParameterAttachment
     void setValueAsPartOfGesture (ParamElementType newValue);
 
     ParamType* param = nullptr;
+    PluginState* pluginState = nullptr;
 
 private:
     template <typename Func>