feature(effects): EffectPreset::updateParametersFrom(EffectPreset&)

src/effects/presets/effectpreset.cpp

@@ -99,5 +99,22 @@ const QDomElement EffectPreset::toXml(QDomDocument* doc) const {
     return effectElement;
 }
 
-EffectPreset::~EffectPreset() {
+void EffectPreset::updateParametersFrom(const EffectPreset& other) {
+    DEBUG_ASSERT(backendType() == other.backendType());
+
+    // technically algorithmically inefficient solution O(n²). May be
+    // optimizable by sorting first, gains depend on parameter count
+    for (const auto& parameterToCopy : other.m_effectParameterPresets) {
+        auto currentParameterIt =
+                std::find_if(m_effectParameterPresets.begin(),
+                        m_effectParameterPresets.end(),
+                        [&](const auto& ourParameter) {
+                            return ourParameter.id() == parameterToCopy.id();
+                        });
+        if (currentParameterIt == m_effectParameterPresets.end()) {
+            continue;
+        }
+        // overwrite our parameter by taking a copy of the same parameter from `other`
+        *currentParameterIt = parameterToCopy;
+    }
 }

src/effects/presets/effectpreset.h

@@ -15,7 +15,6 @@ class EffectPreset {
     EffectPreset(const QDomElement& element);
     EffectPreset(const EffectSlotPointer pEffectSlot);
     EffectPreset(const EffectManifestPointer pManifest);
-    ~EffectPreset();
 
     const QDomElement toXml(QDomDocument* doc) const;
 
@@ -39,6 +38,15 @@ class EffectPreset {
         return m_effectParameterPresets;
     }
 
+    /// updates all of the parameters of `this` with the parameters
+    /// of `preset`.
+    /// The operation is not symmetric:
+    /// Parameters which are present on `preset` but not on `this` will
+    /// not be added to `this`
+    /// Parameters present on `this` but not `preset` will keep their previous
+    /// settings
+    void updateParametersFrom(const EffectPreset& preset);
+
   private:
     QString m_id;
     EffectBackendType m_backendType;