Add ability to set iOS artboard volume through RiveModel

Updates the `RiveModel` API with the ability to set and get the volume for the currently set artboard. Any new artboards will default to use the last-set volume of the model. A volume default of 1.0 is set to match rive-cpp's default. `RiveArtboard` is also updated to forward volume calls to the artboard instance, exposing a new `volume` property.

There's an open question whether this belongs in `RiveViewModel`, or `RiveModel`, but I went for `RiveModel` since there's a direct reference to the artboard within the model itself, and an indirect reference through the view model (model?.artboard)

Diffs=
a31cd9761 Add ability to set iOS artboard volume through RiveModel (#7658)

Co-authored-by: David Skuza <david@rive.app>

.rive_head

@@ -1 +1 @@
-114da4e39ba61dd337e8f6f47c1c7b2fb2223915
+a31cd9761efdc411d4c462f065e37d84af04984c

Example-iOS/Source/Examples/SwiftUI/SwiftAudioAssets.swift

@@ -20,6 +20,10 @@ struct SwiftAudioAssets: DismissableView {
     );
     
     var body: some View {
-        riveViewModel.view()
+        riveViewModel
+            .view()
+            .onAppear {
+                riveViewModel.riveModel?.volume = 0.01
+            }
     }
 }

RiveRuntime.xcodeproj/project.pbxproj

@@ -95,6 +95,7 @@
 		E5964A982A9697B600140479 /* RiveEvent.mm in Sources */ = {isa = PBXBuildFile; fileRef = E5964A972A9697B600140479 /* RiveEvent.mm */; };
 		E599DCF92AAFA06100D1E49A /* rating_animation.riv in Resources */ = {isa = PBXBuildFile; fileRef = E599DCF82AAFA06100D1E49A /* rating_animation.riv */; };
 		E599DCFA2AAFA06100D1E49A /* rating_animation.riv in Resources */ = {isa = PBXBuildFile; fileRef = E599DCF82AAFA06100D1E49A /* rating_animation.riv */; };
+		F28DE4532C5002D900F3C379 /* RiveModelTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = F28DE4522C5002D900F3C379 /* RiveModelTests.swift */; };
 /* End PBXBuildFile section */
 
 /* Begin PBXContainerItemProxy section */
@@ -198,6 +199,7 @@
 		E5964A952A965A9300140479 /* RiveEvent.h */ = {isa = PBXFileReference; explicitFileType = sourcecode.cpp.h; path = RiveEvent.h; sourceTree = "<group>"; };
 		E5964A972A9697B600140479 /* RiveEvent.mm */ = {isa = PBXFileReference; explicitFileType = sourcecode.cpp.objcpp; path = RiveEvent.mm; sourceTree = "<group>"; };
 		E599DCF82AAFA06100D1E49A /* rating_animation.riv */ = {isa = PBXFileReference; lastKnownFileType = file; name = rating_animation.riv; path = "Example-iOS/Assets/rating_animation.riv"; sourceTree = SOURCE_ROOT; };
+		F28DE4522C5002D900F3C379 /* RiveModelTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = RiveModelTests.swift; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
 /* Begin PBXFrameworksBuildPhase section */
@@ -389,6 +391,7 @@
 				04BE542C264C1A3300427B39 /* RiveDelegatesTest.swift */,
 				C38BB5F528762B720039E385 /* RiveStateMachineTest.swift */,
 				041265252B0CB41E009400EC /* OutOfBandAssetTest.mm */,
+				F28DE4522C5002D900F3C379 /* RiveModelTests.swift */,
 			);
 			path = Tests;
 			sourceTree = "<group>";
@@ -594,6 +597,7 @@
 				04BE541C264A90D600427B39 /* RiveAnimationLoadTest.mm in Sources */,
 				C9C73EE024FC478900EF9516 /* RiveRuntimeTests.mm in Sources */,
 				04BE5413264943BB00427B39 /* util.mm in Sources */,
+				F28DE4532C5002D900F3C379 /* RiveModelTests.swift in Sources */,
 				04BE54112649434900427B39 /* RiveFileLoadTest.mm in Sources */,
 				C38BB5F628762B720039E385 /* RiveStateMachineTest.swift in Sources */,
 				04BE5418264A818F00427B39 /* RiveAnimationConfigurationsTest.mm in Sources */,

Source/Renderer/RiveArtboard.mm

@@ -319,4 +319,14 @@ static int artInstanceCount = 0;
     }
 }
 
+- (float)volume
+{
+    return _artboardInstance->volume();
+}
+
+- (void)setVolume:(float)volume
+{
+    _artboardInstance->volume(volume);
+}
+
 @end

Source/Renderer/include/RiveArtboard.h

@@ -23,6 +23,8 @@ NS_ASSUME_NONNULL_BEGIN
 //
 @interface RiveArtboard : NSObject
 
+@property(nonatomic, assign) float volume NS_REFINED_FOR_SWIFT;
+
 - (NSString*)name;
 - (CGRect)bounds;
 

Source/RiveModel.swift

@@ -27,7 +27,27 @@ import Combine
     public init(webURL: String, delegate: RiveFileDelegate, loadCdn: Bool) {
         riveFile = RiveFile(httpUrl: webURL, loadCdn:loadCdn, with: delegate)!
     }
-    
+
+    // rive-cpp defaults the volume to 1.0f
+    // This value is used if there is no artboard,
+    // and will be used to set the volume once a model is configured (with an artboard)
+    private var _volume: Float = 1
+
+    /// The volume of the current artboard, if available. Defaults to 1.
+    @objc open var volume: Float {
+        get {
+            if let volume = artboard?.__volume {
+                return volume
+            }
+
+            return _volume
+        }
+        set {
+            _volume = newValue
+            artboard?.__volume = newValue
+        }
+    }
+
     // MARK: - Setters
     
     /// Sets a new Artboard and makes the current StateMachine and Animation nil
@@ -36,6 +56,7 @@ import Combine
             stateMachine = nil
             animation = nil
             artboard = try riveFile.artboard(fromName: name)
+            artboard.__volume = _volume
         }
         catch { throw RiveModelError.invalidArtboard("Name \(name) not found") }
     }
@@ -47,11 +68,15 @@ import Combine
                 stateMachine = nil
                 animation = nil
                 artboard = try riveFile.artboard(from: index)
+                artboard.__volume = _volume
             }
             catch { throw RiveModelError.invalidArtboard("Index \(index) not found") }
         } else {
             // This tries to find the 'default' Artboard
-            do { artboard = try riveFile.artboard() }
+            do {
+                artboard = try riveFile.artboard()
+                artboard.__volume = _volume
+            }
             catch { throw RiveModelError.invalidArtboard("No Default Artboard") }
         }
     }

Source/RiveViewModel.swift

@@ -180,7 +180,6 @@ import Combine
         didSet { riveView?.fit = fit }
     }
     
-    
     open var alignment: RiveAlignment = .center {
         didSet { riveView?.alignment = alignment }
     }

Tests/RiveModelTests.swift

@@ -0,0 +1,38 @@
+//
+//  RiveModelTests.swift
+//  RiveRuntimeTests
+//
+//  Created by David Skuza on 7/23/24.
+//  Copyright © 2024 Rive. All rights reserved.
+//
+
+import XCTest
+@testable import RiveRuntime
+
+class RiveModelTests: XCTestCase {
+    func test_volume() throws {
+        let file = try RiveFile(testfileName: "multipleartboards")
+        let model = RiveModel(riveFile: file)
+
+        XCTAssertEqual(model.volume, 1)
+
+        do {
+            try model.setArtboard()
+
+            model.volume = 0.5
+            XCTAssertEqual(model.volume, 0.5)
+            XCTAssertEqual(model.artboard?.__volume, 0.5)
+        }
+
+        do {
+            try model.setArtboard("artboard2")
+
+            XCTAssertEqual(model.volume, 0.5)
+            XCTAssertEqual(model.artboard?.__volume, 0.5)
+
+            model.volume = 0
+            XCTAssertEqual(model.volume, 0)
+            XCTAssertEqual(model.artboard?.__volume, 0)
+        }
+    }
+}