refactor: conditional addListener on type match

Author: HayesGordon

ios/BaseHybridViewModelProperty.swift

@@ -3,6 +3,9 @@ import RiveRuntime
 
 /// Protocol for Rive property types that support listener management
 protocol RivePropertyWithListeners: AnyObject {
+  associatedtype ListenerValueType
+  
+  func addListener(_ callback: @escaping (ListenerValueType) -> Void) -> UUID
   func removeListener(_ id: UUID)
 }
 
@@ -15,16 +18,24 @@ typealias TriggerPropertyType = RiveDataBindingViewModel.Instance.TriggerPropert
 typealias ImagePropertyType = RiveDataBindingViewModel.Instance.ImageProperty
 
 // Make all Rive property types conform to the protocol
-extension BooleanPropertyType: RivePropertyWithListeners {}
-extension NumberPropertyType: RivePropertyWithListeners {}
-extension StringPropertyType: RivePropertyWithListeners {}
-extension EnumPropertyType: RivePropertyWithListeners {}
-extension ColorPropertyType: RivePropertyWithListeners {}
-extension TriggerPropertyType: RivePropertyWithListeners {}
-extension ImagePropertyType: RivePropertyWithListeners {}
+extension BooleanPropertyType: RivePropertyWithListeners {
+  typealias ListenerValueType = Bool  // Native: Bool → Bool (no conversion)
+}
+extension NumberPropertyType: RivePropertyWithListeners {
+  typealias ListenerValueType = Float  // Native: Float → Double (needs conversion)
+}
+extension StringPropertyType: RivePropertyWithListeners {
+  typealias ListenerValueType = String  // Native: String → String (no conversion)
+}
+extension EnumPropertyType: RivePropertyWithListeners {
+  typealias ListenerValueType = String  // Native: String → String (no conversion)
+}
+extension ColorPropertyType: RivePropertyWithListeners {
+  typealias ListenerValueType = UIColor  // Native: UIColor → Double (needs conversion)
+}
+// Note: TriggerProperty doesn't fit the pattern - it has () -> Void listeners, not (Void) -> Void
 
 /// Helper class for managing ViewModel property listeners
-/// Similar to Android's BaseHybridViewModelPropertyImpl, provides reusable listener management
 class PropertyListenerHelper<PropertyType: RivePropertyWithListeners> {
   private var listenerIds: [UUID] = []
   weak var property: PropertyType?
@@ -33,11 +44,10 @@ class PropertyListenerHelper<PropertyType: RivePropertyWithListeners> {
     self.property = property
   }
 
-  /// Adds a listener and automatically tracks its ID for later cleanup
-  /// - Parameter addListener: Closure that adds the listener to the property and returns the listener ID
-  func trackListener(_ addListener: (PropertyType) -> UUID) {
+  /// Adds a listener to the property and automatically tracks its ID for cleanup
+  func addListener(_ callback: @escaping (PropertyType.ListenerValueType) -> Void) {
     guard let property = property else { return }
-    let id = addListener(property)
+    let id = property.addListener(callback)
     listenerIds.append(id)
   }
 
@@ -54,19 +64,23 @@ class PropertyListenerHelper<PropertyType: RivePropertyWithListeners> {
   }
 }
 
-/// Protocol that provides common functionality for all hybrid ViewModel property classes
-/// Reduces boilerplate by providing default implementations for listener management
-protocol ViewModelPropertyProtocol {
+/// Protocol for properties that have typed values (Bool, String, Double, etc.)
+/// Provides a default addListener implementation
+protocol ValuedPropertyProtocol<ValueType>{
   associatedtype PropertyType: RivePropertyWithListeners
+  associatedtype ValueType
 
+  var property: PropertyType! { get }
   var helper: PropertyListenerHelper<PropertyType> { get }
-  
+
+  func addListener(onChanged: @escaping (ValueType) -> Void) throws
   func removeListeners() throws
   func dispose() throws
 }
 
-/// Default implementations for common listener management methods
-extension ViewModelPropertyProtocol {
+
+/// Default implementations for lifecycle methods (always available)
+extension ValuedPropertyProtocol {
   func removeListeners() throws {
     try helper.removeListeners()
   }
@@ -76,3 +90,10 @@ extension ViewModelPropertyProtocol {
   }
 }
 
+/// Automatic addListener() ONLY when ListenerValueType == ValueType (no conversion needed)
+extension ValuedPropertyProtocol where PropertyType.ListenerValueType == ValueType {
+  func addListener(onChanged: @escaping (ValueType) -> Void) throws {
+    helper.addListener(onChanged)  // Types match, just forward directly!
+  }
+}
+

ios/HybridViewModelBooleanProperty.swift

@@ -1,8 +1,8 @@
 import NitroModules
 import RiveRuntime
 
-class HybridViewModelBooleanProperty: HybridViewModelBooleanPropertySpec, ViewModelPropertyProtocol {
-  private var property: BooleanPropertyType!
+class HybridViewModelBooleanProperty: HybridViewModelBooleanPropertySpec, ValuedPropertyProtocol {
+  var property: BooleanPropertyType!
   lazy var helper = PropertyListenerHelper(property: property!)
 
   init(property: BooleanPropertyType) {
@@ -26,12 +26,4 @@ class HybridViewModelBooleanProperty: HybridViewModelBooleanPropertySpec, ViewMo
       property.value = newValue
     }
   }
-  
-  func addListener(onChanged: @escaping (Bool) -> Void) throws {
-    helper.trackListener { property in
-      property.addListener { value in
-        onChanged(value)
-      }
-    }
-  }
 }

ios/HybridViewModelColorProperty.swift

@@ -1,8 +1,8 @@
 import NitroModules
 import RiveRuntime
 
-class HybridViewModelColorProperty: HybridViewModelColorPropertySpec, ViewModelPropertyProtocol {
-  private var property: ColorPropertyType!
+class HybridViewModelColorProperty: HybridViewModelColorPropertySpec, ValuedPropertyProtocol {
+  var property: ColorPropertyType!
   lazy var helper = PropertyListenerHelper(property: property!)
 
   init(property: ColorPropertyType) {
@@ -27,11 +27,10 @@ class HybridViewModelColorProperty: HybridViewModelColorPropertySpec, ViewModelP
     }
   }
 
+  // Custom addListener because we need to convert UIColor → Double
   func addListener(onChanged: @escaping (Double) -> Void) throws {
-    helper.trackListener { property in
-      property.addListener { value in
-        onChanged(value.toHexDouble())
-      }
+    helper.addListener { (color: UIColor) in
+      onChanged(color.toHexDouble())
     }
   }
 }

ios/HybridViewModelEnumProperty.swift

@@ -1,8 +1,8 @@
 import NitroModules
 import RiveRuntime
 
-class HybridViewModelEnumProperty: HybridViewModelEnumPropertySpec, ViewModelPropertyProtocol {
-  private var property: EnumPropertyType!
+class HybridViewModelEnumProperty: HybridViewModelEnumPropertySpec, ValuedPropertyProtocol {
+  var property: EnumPropertyType!
   lazy var helper = PropertyListenerHelper(property: property!)
 
   init(property: EnumPropertyType) {
@@ -26,12 +26,4 @@ class HybridViewModelEnumProperty: HybridViewModelEnumPropertySpec, ViewModelPro
       property.value = newValue
     }
   }
-  
-  func addListener(onChanged: @escaping (String) -> Void) throws {
-    helper.trackListener { property in
-      property.addListener { value in
-        onChanged(value)
-      }
-    }
-  }
 }

ios/HybridViewModelNumberProperty.swift

@@ -1,6 +1,6 @@
 import RiveRuntime
 
-class HybridViewModelNumberProperty: HybridViewModelNumberPropertySpec, ViewModelPropertyProtocol {
+class HybridViewModelNumberProperty: HybridViewModelNumberPropertySpec, ValuedPropertyProtocol {
   var property: NumberPropertyType!
   lazy var helper = PropertyListenerHelper(property: property!)
 
@@ -26,12 +26,10 @@ class HybridViewModelNumberProperty: HybridViewModelNumberPropertySpec, ViewMode
     }
   }
 
+  // Custom addListener needed because ListenerValueType (Float) != ValueType (Double)
   func addListener(onChanged: @escaping (Double) -> Void) throws {
-    helper.trackListener { property in
-      property.addListener { value in
-        onChanged(Double(value))
-      }
+    helper.addListener { (value: Float) in
+      onChanged(Double(value))
     }
   }
-  
 }

ios/HybridViewModelStringProperty.swift

@@ -1,8 +1,8 @@
 import NitroModules
 import RiveRuntime
 
-class HybridViewModelStringProperty: HybridViewModelStringPropertySpec, ViewModelPropertyProtocol {
-  private var property: StringPropertyType!
+class HybridViewModelStringProperty: HybridViewModelStringPropertySpec, ValuedPropertyProtocol {
+  var property: StringPropertyType!
   lazy var helper = PropertyListenerHelper(property: property!)
 
   init(property: StringPropertyType) {
@@ -26,13 +26,4 @@ class HybridViewModelStringProperty: HybridViewModelStringPropertySpec, ViewMode
       property.value = newValue
     }
   }
-  
-  func addListener(onChanged: @escaping (String) -> Void) throws {
-    helper.trackListener { property in
-      property.addListener { value in
-        onChanged(value)
-      }
-    }
-  }
-  
 }

ios/HybridViewModelTriggerProperty.swift

@@ -1,9 +1,9 @@
 import NitroModules
 import RiveRuntime
 
-class HybridViewModelTriggerProperty: HybridViewModelTriggerPropertySpec, ViewModelPropertyProtocol {
+class HybridViewModelTriggerProperty: HybridViewModelTriggerPropertySpec {
   private var property: TriggerPropertyType!
-  lazy var helper = PropertyListenerHelper(property: property!)
+  private var listenerIds: [UUID] = []
 
   init(property: TriggerPropertyType) {
     self.property = property
@@ -23,11 +23,20 @@ class HybridViewModelTriggerProperty: HybridViewModelTriggerPropertySpec, ViewMo
   }
 
   func addListener(onChanged: @escaping () -> Void) throws {
-    helper.trackListener { property in
-      property.addListener {
-        onChanged()
-      }
+    let id = property.addListener {
+      onChanged()
     }
+    listenerIds.append(id)
   }
 
+  func removeListeners() throws {
+    for id in listenerIds {
+      property.removeListener(id)
+    }
+    listenerIds.removeAll()
+  }
+  
+  func dispose() throws {
+    try? removeListeners()
+  }
 }