Update effect sliders when DAW changes parameter

Source/PluginProcessor.h

@@ -92,7 +92,7 @@ public:
         [this](int index, Vector2 input, const std::vector<double>& values, double sampleRate) {
             threshold = values[0];
             return input;
-        }, std::vector<EffectParameter>(1, { "Threshold", "threshold", 3.0, 0.0, 3.0 })
+        }, std::vector<EffectParameter>(1, { "Threshold", "threshold", 1.0, 0.0, 1.0 })
     );
     
     std::shared_ptr<Effect> focalLength = std::make_shared<Effect>(

Source/audio/Effect.cpp

@@ -53,6 +53,18 @@ void Effect::setPrecedence(int precedence) {
 	this->precedence = precedence;
 }
 
+void Effect::addListener(int index, juce::AudioProcessorParameter::Listener* listener) {
+	juce::SpinLock::ScopedLockType lock(listenerLock);
+	parameters[index].addListener(listener);
+	enabled.addListener(listener);
+}
+
+void Effect::removeListener(int index, juce::AudioProcessorParameter::Listener* listener) {
+    juce::SpinLock::ScopedLockType lock(listenerLock);
+    parameters[index].removeListener(listener);
+    enabled.removeListener(listener);
+}
+
 juce::String Effect::getId() {
 	return parameters[0].id;
 }

Source/audio/Effect.h

@@ -21,6 +21,8 @@ public:
 	void setValue(double value);
 	int getPrecedence();
 	void setPrecedence(int precedence);
+	void addListener(int index, juce::AudioProcessorParameter::Listener* listener);
+	void removeListener(int index, juce::AudioProcessorParameter::Listener* listener);
 	juce::String getId();
 	juce::String getName();
 
@@ -29,6 +31,7 @@ public:
 
 private:
 	
+	juce::SpinLock listenerLock;
 	std::vector<double> smoothValues;
 	double frequency = 1.0;
 	int precedence = -1;

Source/components/EffectComponent.cpp

@@ -1,7 +1,10 @@
 #include "EffectComponent.h"
 
 EffectComponent::EffectComponent(Effect& effect, int index) : effect(effect), index(index) {
-    componentSetup();
+    addAndMakeVisible(slider);
+    addAndMakeVisible(selected);
+    effect.addListener(index, this);
+    setupComponent();
 }
 
 EffectComponent::EffectComponent(Effect& effect, int index, bool checkboxVisible) : EffectComponent(effect, index) {
@@ -14,10 +17,7 @@ EffectComponent::EffectComponent(Effect& effect, bool checkboxVisible) : EffectC
     setCheckboxVisible(checkboxVisible);
 }
 
-void EffectComponent::componentSetup() {
-    addAndMakeVisible(slider);
-    addAndMakeVisible(selected);
-
+void EffectComponent::setupComponent() {
     EffectParameter& parameter = effect.parameters[index];
 
     slider.setRange(parameter.min, parameter.max, parameter.step);
@@ -26,7 +26,7 @@ void EffectComponent::componentSetup() {
     slider.setSliderStyle(juce::Slider::LinearHorizontal);
     slider.setTextBoxStyle(juce::Slider::TextBoxRight, false, 90, slider.getTextBoxHeight());
 
-    selected.setToggleState(false, juce::dontSendNotification);
+    selected.setToggleState(effect.enabled.getValue(), juce::dontSendNotification);
 
     min.textBox.setValue(parameter.min, juce::dontSendNotification);
     max.textBox.setValue(parameter.max, juce::dontSendNotification);
@@ -59,7 +59,9 @@ void EffectComponent::componentSetup() {
 }
 
 
-EffectComponent::~EffectComponent() {}
+EffectComponent::~EffectComponent() {
+    effect.removeListener(index, this);
+}
 
 void EffectComponent::resized() {
     auto sliderRight = getWidth() - 160;
@@ -97,6 +99,16 @@ void EffectComponent::mouseDown(const juce::MouseEvent& event) {
     }
 }
 
+void EffectComponent::parameterValueChanged(int parameterIndex, float newValue) {
+    triggerAsyncUpdate();
+}
+
+void EffectComponent::parameterGestureChanged(int parameterIndex, bool gestureIsStarting) {}
+
+void EffectComponent::handleAsyncUpdate() {
+    setupComponent();
+}
+
 void EffectComponent::setComponent(std::shared_ptr<juce::Component> component) {
 	this->component = component;
     addAndMakeVisible(component.get());

Source/components/EffectComponent.h

@@ -5,7 +5,7 @@
 #include "LabelledTextBox.h"
 
 
-class EffectComponent : public juce::Component {
+class EffectComponent : public juce::Component, public juce::AudioProcessorParameter::Listener, juce::AsyncUpdater {
 public:
     EffectComponent(Effect& effect, int index);
     EffectComponent(Effect& effect, int index, bool checkboxVisible);
@@ -16,6 +16,9 @@ public:
     void resized() override;
     void paint(juce::Graphics& g) override;
     void mouseDown(const juce::MouseEvent& event) override;
+    void parameterValueChanged(int parameterIndex, float newValue) override;
+    void parameterGestureChanged(int parameterIndex, bool gestureIsStarting) override;
+    void handleAsyncUpdate() override;
 
     void setCheckboxVisible(bool visible);
     void setComponent(std::shared_ptr<juce::Component> component);
@@ -26,7 +29,7 @@ public:
     juce::ToggleButton selected;
 
 private:
-    void componentSetup();
+    void setupComponent();
     bool checkboxVisible = true;
     juce::Rectangle<int> textBounds;
     std::shared_ptr<juce::Component> component;

Source/components/EffectsListComponent.cpp

@@ -14,8 +14,6 @@ EffectsListComponent::EffectsListComponent(DraggableListBox& lb, AudioEffectList
 		};
 
 		if (i == 0) {
-			bool isSelected = effect->enabled.getValue();
-			effectComponent->selected.setToggleState(isSelected, juce::dontSendNotification);
 			effectComponent->selected.onClick = [this, weakEffectComponent] {
 				if (auto effectComponent = weakEffectComponent.lock()) {
 					auto data = (AudioEffectListBoxItemData&)modelData;

Source/components/VolumeComponent.cpp

@@ -11,8 +11,9 @@ VolumeComponent::VolumeComponent(OscirenderAudioProcessor& p) : audioProcessor(p
     volumeSlider.setColour(juce::Slider::ColourIds::backgroundColourId, juce::Colours::transparentWhite);
     volumeSlider.setColour(juce::Slider::ColourIds::trackColourId, juce::Colours::transparentWhite);
     volumeSlider.setOpaque(false);
-    volumeSlider.setRange(0, 2, 0.001);
-    volumeSlider.setValue(1);
+    auto& volumeParam = audioProcessor.volumeEffect->parameters[0];
+    volumeSlider.setRange(volumeParam.min, volumeParam.max, volumeParam.step);
+    volumeSlider.setValue(volumeParam.getValueUnnormalised());
     volumeSlider.setLookAndFeel(&thumbRadiusLookAndFeel);
     volumeSlider.setColour(juce::Slider::ColourIds::thumbColourId, juce::Colours::black);
 
@@ -22,8 +23,9 @@ VolumeComponent::VolumeComponent(OscirenderAudioProcessor& p) : audioProcessor(p
     thresholdSlider.setColour(juce::Slider::ColourIds::backgroundColourId, juce::Colours::transparentWhite);
     thresholdSlider.setColour(juce::Slider::ColourIds::trackColourId, juce::Colours::transparentWhite);
     thresholdSlider.setOpaque(false);
-    thresholdSlider.setRange(0, 1, 0.001);
-    thresholdSlider.setValue(1);
+    auto& thresholdParam = audioProcessor.thresholdEffect->parameters[0];
+    thresholdSlider.setRange(thresholdParam.min, thresholdParam.max, thresholdParam.step);
+    thresholdSlider.setValue(thresholdParam.getValueUnnormalised());
     thresholdSlider.setLookAndFeel(&thresholdLookAndFeel);
     thresholdSlider.setColour(juce::Slider::ColourIds::thumbColourId, juce::Colours::black);
 
@@ -85,6 +87,8 @@ void VolumeComponent::paint(juce::Graphics& g) {
 
 void VolumeComponent::timerCallback() {
     repaint();
+    volumeSlider.setValue(audioProcessor.volumeEffect->getValue(), juce::NotificationType::dontSendNotification);
+    thresholdSlider.setValue(audioProcessor.thresholdEffect->getValue(), juce::NotificationType::dontSendNotification);
 }
 
 void VolumeComponent::run() {