Support animating multiple properties of shape bezier paths

Sources/Private/CoreAnimation/Animations/EllipseAnimation.swift

@@ -14,15 +14,42 @@ extension CAShapeLayer {
   {
     try addAnimation(
       for: .path,
-      keyframes: ellipse.size.keyframes,
-      value: { sizeKeyframe in
+      keyframes: ellipse.combinedKeyframes(context: context).keyframes,
+      value: { keyframe in
         BezierPath.ellipse(
-          size: sizeKeyframe.sizeValue,
-          center: try ellipse.position.exactlyOneKeyframe(context: context, description: "ellipse position").value.pointValue,
+          size: keyframe.size.sizeValue,
+          center: keyframe.position.pointValue,
           direction: ellipse.direction)
           .cgPath()
           .duplicated(times: pathMultiplier)
       },
       context: context)
   }
 }
+
+extension Ellipse {
+  /// Data that represents how to render an ellipse at a specific point in time
+  struct Keyframe {
+    let size: Vector3D
+    let position: Vector3D
+  }
+
+  /// Creates a single array of animatable keyframes from the separate arrays of keyframes in this Ellipse
+  func combinedKeyframes(context: LayerAnimationContext) throws-> KeyframeGroup<Ellipse.Keyframe> {
+    let combinedKeyframes = Keyframes.combinedIfPossible(
+      size, position,
+      makeCombinedResult: Ellipse.Keyframe.init)
+
+    if let combinedKeyframes = combinedKeyframes {
+      return combinedKeyframes
+    } else {
+      // If we weren't able to combine all of the keyframes, we have to take the timing values
+      // from one property and use a fixed value for the other properties.
+      return try size.map { sizeValue in
+        Keyframe(
+          size: sizeValue,
+          position: try position.exactlyOneKeyframe(context: context, description: "ellipse position"))
+      }
+    }
+  }
+}

Sources/Private/CoreAnimation/Animations/GradientAnimations.swift

@@ -104,10 +104,10 @@ extension GradientRenderLayer {
     // at any given time requires knowing the current `startPoint`,
     // we can't allow them to animate separately.
     let absoluteStartPoint = try gradient.startPoint
-      .exactlyOneKeyframe(context: context, description: "gradient startPoint").value.pointValue
+      .exactlyOneKeyframe(context: context, description: "gradient startPoint").pointValue
 
     let absoluteEndPoint = try gradient.endPoint
-      .exactlyOneKeyframe(context: context, description: "gradient endPoint").value.pointValue
+      .exactlyOneKeyframe(context: context, description: "gradient endPoint").pointValue
 
     startPoint = percentBasedPointInBounds(from: absoluteStartPoint)
 

Sources/Private/CoreAnimation/Animations/RectangleAnimation.swift

@@ -14,18 +14,45 @@ extension CAShapeLayer {
   {
     try addAnimation(
       for: .path,
-      keyframes: rectangle.size.keyframes,
-      value: { sizeKeyframe in
+      keyframes: try rectangle.combinedKeyframes(context: context).keyframes,
+      value: { keyframe in
         BezierPath.rectangle(
-          position: try rectangle.position
-            .exactlyOneKeyframe(context: context, description: "rectangle position").value.pointValue,
-          size: sizeKeyframe.sizeValue,
-          cornerRadius: try rectangle.cornerRadius
-            .exactlyOneKeyframe(context: context, description: "rectangle cornerRadius").value.cgFloatValue,
+          position: keyframe.position.pointValue,
+          size: keyframe.size.sizeValue,
+          cornerRadius: keyframe.cornerRadius.cgFloatValue,
           direction: rectangle.direction)
           .cgPath()
           .duplicated(times: pathMultiplier)
       },
       context: context)
   }
 }
+
+extension Rectangle {
+  /// Data that represents how to render a rectangle at a specific point in time
+  struct Keyframe {
+    let size: Vector3D
+    let position: Vector3D
+    let cornerRadius: Vector1D
+  }
+
+  /// Creates a single array of animatable keyframes from the separate arrays of keyframes in this Rectangle
+  func combinedKeyframes(context: LayerAnimationContext) throws-> KeyframeGroup<Rectangle.Keyframe> {
+    let combinedKeyframes = Keyframes.combinedIfPossible(
+      size, position, cornerRadius,
+      makeCombinedResult: Rectangle.Keyframe.init)
+
+    if let combinedKeyframes = combinedKeyframes {
+      return combinedKeyframes
+    } else {
+      // If we weren't able to combine all of the keyframes, we have to take the timing values
+      // from one property and use a fixed value for the other properties.
+      return try size.map { sizeValue in
+        Keyframe(
+          size: sizeValue,
+          position: try position.exactlyOneKeyframe(context: context, description: "rectangle position"),
+          cornerRadius: try cornerRadius.exactlyOneKeyframe(context: context, description: "rectangle cornerRadius"))
+      }
+    }
+  }
+}

Sources/Private/CoreAnimation/Animations/StarAnimation.swift

@@ -36,25 +36,16 @@ extension CAShapeLayer {
   {
     try addAnimation(
       for: .path,
-      keyframes: star.position.keyframes,
-      value: { position in
-        // We can only use one set of keyframes to animate a given CALayer keypath,
-        // so we currently animate `position` and ignore any other keyframes.
-        // TODO: Is there a way to support this properly?
+      keyframes: try star.combinedKeyframes(context: context).keyframes,
+      value: { keyframe in
         BezierPath.star(
-          position: position.pointValue,
-          outerRadius: try star.outerRadius
-            .exactlyOneKeyframe(context: context, description: "outerRadius").value.cgFloatValue,
-          innerRadius: try star.innerRadius?
-            .exactlyOneKeyframe(context: context, description: "innerRadius").value.cgFloatValue ?? 0,
-          outerRoundedness: try star.outerRoundness
-            .exactlyOneKeyframe(context: context, description: "outerRoundness").value.cgFloatValue,
-          innerRoundedness: try star.innerRoundness?
-            .exactlyOneKeyframe(context: context, description: "innerRoundness").value.cgFloatValue ?? 0,
-          numberOfPoints: try star.points
-            .exactlyOneKeyframe(context: context, description: "points").value.cgFloatValue,
-          rotation: try star.rotation
-            .exactlyOneKeyframe(context: context, description: "rotation").value.cgFloatValue,
+          position: keyframe.position.pointValue,
+          outerRadius: keyframe.outerRadius.cgFloatValue,
+          innerRadius: keyframe.innerRadius.cgFloatValue,
+          outerRoundedness: keyframe.outerRoundness.cgFloatValue,
+          innerRoundedness: keyframe.innerRoundness.cgFloatValue,
+          numberOfPoints: keyframe.points.cgFloatValue,
+          rotation: keyframe.rotation.cgFloatValue,
           direction: star.direction)
           .cgPath()
           .duplicated(times: pathMultiplier)
@@ -71,25 +62,63 @@ extension CAShapeLayer {
   {
     try addAnimation(
       for: .path,
-      keyframes: star.position.keyframes,
-      value: { position in
-        // We can only use one set of keyframes to animate a given CALayer keypath,
-        // so we currently animate `position` and ignore any other keyframes.
-        // TODO: Is there a way to support this properly?
+      keyframes: try star.combinedKeyframes(context: context).keyframes,
+      value: { keyframe in
         BezierPath.polygon(
-          position: position.pointValue,
-          numberOfPoints: try star.points
-            .exactlyOneKeyframe(context: context, description: "numberOfPoints").value.cgFloatValue,
-          outerRadius: try star.outerRadius
-            .exactlyOneKeyframe(context: context, description: "outerRadius").value.cgFloatValue,
-          outerRoundedness: try star.outerRoundness
-            .exactlyOneKeyframe(context: context, description: "outerRoundedness").value.cgFloatValue,
-          rotation: try star.rotation
-            .exactlyOneKeyframe(context: context, description: "rotation").value.cgFloatValue,
+          position: keyframe.position.pointValue,
+          numberOfPoints: keyframe.points.cgFloatValue,
+          outerRadius: keyframe.outerRadius.cgFloatValue,
+          outerRoundedness: keyframe.outerRoundness.cgFloatValue,
+          rotation: keyframe.rotation.cgFloatValue,
           direction: star.direction)
           .cgPath()
           .duplicated(times: pathMultiplier)
       },
       context: context)
   }
 }
+
+extension Star {
+  /// Data that represents how to render a star at a specific point in time
+  struct Keyframe {
+    let position: Vector3D
+    let outerRadius: Vector1D
+    let innerRadius: Vector1D
+    let outerRoundness: Vector1D
+    let innerRoundness: Vector1D
+    let points: Vector1D
+    let rotation: Vector1D
+  }
+
+  /// Creates a single array of animatable keyframes from the separate arrays of keyframes in this star/polygon
+  func combinedKeyframes(context: LayerAnimationContext) throws -> KeyframeGroup<Keyframe> {
+    let combinedKeyframes = Keyframes.combinedIfPossible(
+      position,
+      outerRadius,
+      innerRadius ?? KeyframeGroup(Vector1D(0)),
+      outerRoundness,
+      innerRoundness ?? KeyframeGroup(Vector1D(0)),
+      points,
+      rotation,
+      makeCombinedResult: Star.Keyframe.init)
+
+    if let combinedKeyframes = combinedKeyframes {
+      return combinedKeyframes
+    } else {
+      // If we weren't able to combine all of the keyframes, we have to take the timing values
+      // from one property and use a fixed value for the other properties.
+      return try position.map { positionValue in
+        Keyframe(
+          position: positionValue,
+          outerRadius: try outerRadius.exactlyOneKeyframe(context: context, description: "star outerRadius"),
+          innerRadius: try innerRadius?.exactlyOneKeyframe(context: context, description: "star innerRadius")
+            ?? Vector1D(0),
+          outerRoundness: try outerRoundness.exactlyOneKeyframe(context: context, description: "star outerRoundness"),
+          innerRoundness: try innerRoundness?.exactlyOneKeyframe(context: context, description: "star innerRoundness")
+            ?? Vector1D(0),
+          points: try points.exactlyOneKeyframe(context: context, description: "star points"),
+          rotation: try rotation.exactlyOneKeyframe(context: context, description: "star rotation"))
+      }
+    }
+  }
+}

Sources/Private/CoreAnimation/Animations/StrokeAnimation.swift

@@ -57,7 +57,7 @@ extension CAShapeLayer {
     if let (dashPattern, dashPhase) = stroke.dashPattern?.shapeLayerConfiguration {
       lineDashPattern = try dashPattern.map {
         try KeyframeGroup(keyframes: $0)
-          .exactlyOneKeyframe(context: context, description: "stroke dashPattern").value.cgFloatValue as NSNumber
+          .exactlyOneKeyframe(context: context, description: "stroke dashPattern").cgFloatValue as NSNumber
       }
 
       try addAnimation(

Sources/Private/CoreAnimation/Extensions/KeyframeGroup+exactlyOneKeyframe.swift

@@ -23,7 +23,7 @@ extension KeyframeGroup {
     fileID _: StaticString = #fileID,
     line _: UInt = #line)
     throws
-    -> Keyframe<T>
+    -> T
   {
     try context.compatibilityAssert(
       keyframes.count == 1,
@@ -32,6 +32,6 @@ extension KeyframeGroup {
       for \(description) values (due to limitations of Core Animation `CAKeyframeAnimation`s).
       """)
 
-    return keyframes[0]
+    return keyframes[0].value
   }
 }