Update comment

Sources/TokamakCore/Animation/Animation.swift

@@ -0,0 +1,105 @@
+// Copyright 2020 Tokamak contributors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+let defaultDuration = 0.35
+
+public struct Animation: Equatable {
+  static let `default` = Animation()
+
+  public func delay(_ delay: Double) -> Animation {
+    .init()
+  }
+
+  public func speed(_ speed: Double) -> Animation {
+    .init()
+  }
+
+  public func repeatCount(
+    _ repeatCount: Int,
+    autoreverses: Bool = true
+  ) -> Animation {
+    .init()
+  }
+
+  public func repeatForever(autoreverses: Bool = true) -> Animation {
+    .init()
+  }
+
+  public static func spring(
+    response: Double = 0.55,
+    dampingFraction: Double = 0.825,
+    blendDuration: Double = 0
+  ) -> Animation {
+    .init()
+  }
+
+  public static func interactiveSpring(
+    response: Double = 0.15,
+    dampingFraction: Double = 0.86,
+    blendDuration: Double = 0.25
+  ) -> Animation {
+    .init()
+  }
+
+  public static func interpolatingSpring(
+    mass: Double = 1.0,
+    stiffness: Double,
+    damping: Double,
+    initialVelocity: Double = 0.0
+  ) -> Animation {
+    .init()
+  }
+
+  public static func easeInOut(duration: Double) -> Animation {
+    .init()
+  }
+
+  public static var easeInOut: Animation {
+    easeInOut(duration: defaultDuration)
+  }
+
+  public static func easeIn(duration: Double) -> Animation {
+    .init()
+  }
+
+  public static var easeIn: Animation {
+    easeIn(duration: defaultDuration)
+  }
+
+  public static func easeOut(duration: Double) -> Animation {
+    .init()
+  }
+
+  public static var easeOut: Animation {
+    easeOut(duration: defaultDuration)
+  }
+
+  public static func linear(duration: Double) -> Animation {
+    timingCurve(0, 0, 1, 1, duration: duration)
+  }
+
+  public static var linear: Animation {
+    timingCurve(0, 0, 1, 1)
+  }
+
+  public static func timingCurve(
+    _ c0x: Double,
+    _ c0y: Double,
+    _ c1x: Double,
+    _ c1y: Double,
+    duration: Double = defaultDuration
+  ) -> Animation {
+    .init()
+  }
+}

Sources/TokamakCore/Animation/Transaction.swift

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+// Copyright 2020 Tokamak contributors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+public struct Transaction {
+  public var animation: Animation?
+
+  /** `true` in the first part of the transition update, this avoids situations when `animation(_:)`
+   could add more animations to this transaction.
+   */
+  public var disablesAnimations: Bool
+
+  public init(animation: Animation?) {
+    self.animation = animation
+    disablesAnimations = true
+  }
+}