Improve internal representation of default transition (#36)

Author: davdroman

Sources/NavigationTransition/AnyNavigationTransition.swift

@@ -20,17 +20,17 @@ public struct AnyNavigationTransition {
         case primitive(PrimitiveHandler)
     }
 
-    @_spi(package)public let type: Any.Type
+    @_spi(package)public let isDefault: Bool
     @_spi(package)public let handler: Handler
     @_spi(package)public var animation: Animation = .default
 
     public init<T: NavigationTransition>(_ transition: T) {
-        self.type = Swift.type(of: transition)
+        self.isDefault = false
         self.handler = .transient(transition.transition(from:to:for:in:))
     }
 
     public init<T: PrimitiveNavigationTransition>(_ transition: T) {
-        self.type = Swift.type(of: transition)
+        self.isDefault = transition is Default
         self.handler = .primitive(transition.transition(with:for:in:))
     }
 }

Sources/NavigationTransition/Default.swift

@@ -17,22 +17,10 @@ extension AnyNavigationTransition {
     }
 }
 
-@_spi(package)public struct Default: NavigationTransition {
+@_spi(package)public struct Default: PrimitiveNavigationTransition {
     init() {}
 
-    public func transition(
-        from fromView: TransientView,
-        to toView: TransientView,
-        for operation: TransitionOperation,
-        in container: Container
-    ) {
-        runtimeWarn(
-            """
-            'Default' transition was used in conjunction with another transition.
-            This won't produce the expected outcome, as 'Default' is a special-cased transition only used
-            as a reference to the system default navigation transition and doesn't actually contain information
-            about how the transition is performed.
-            """
-        )
+    public func transition(with animator: Animator, for operation: TransitionOperation, in context: Context) {
+        // NO-OP
     }
 }

Sources/NavigationTransitions/NavigationTransition+UIKit.swift

@@ -142,7 +142,7 @@ extension UINavigationController {
             defaultDelegate = delegate
         }
 
-        if transition.type == Default.self {
+        if transition.isDefault {
             delegate = defaultDelegate
         } else {
             customDelegate = NavigationTransitionDelegate(transition: transition, baseDelegate: defaultDelegate)
@@ -171,7 +171,7 @@ extension UINavigationController {
             view.addGestureRecognizer(panRecognizer)
         }
 
-        if transition.type == Default.self {
+        if transition.isDefault {
             switch interactivity {
             case .disabled:
                 exclusivelyEnableGestureRecognizer(.none)