Use designated initialisers for ShadowViewMutation

Summary:
changelog: [internal]

In this diff, we delete default initialised for ShadowViewMutation to prevent accidentally creating empty ShadowViewMutation.
The other initialiser is made private and all of its uses are migrated to designated initialisers. This makes for safer API.

Reviewed By: RSNara

Differential Revision: D30774900

fbshipit-source-id: d2064bf08409850e75e13ad06558b7980a7f5d8d

ReactCommon/react/renderer/animations/LayoutAnimationKeyFrameManager.cpp

@@ -12,6 +12,7 @@
 #include <react/debug/flags.h>
 #include <react/debug/react_native_assert.h>
 
+#include <logger/react_native_log.h>
 #include <react/renderer/animations/conversions.h>
 #include <react/renderer/animations/utils.h>
 #include <react/renderer/componentregistry/ComponentDescriptorFactory.h>
@@ -432,12 +433,11 @@ LayoutAnimationKeyFrameManager::pullTransaction(
                 // that is being referenced by the REMOVE mutation.
                 if (keyframe.type == AnimationConfigurationType::Update &&
                     mutation.oldChildShadowView.tag > 0) {
-                  executeMutationImmediately = ShadowViewMutation{
-                      /* .type = */ mutation.type,
-                      /* .parentShadowView = */ mutation.parentShadowView,
-                      /* .oldChildShadowView = */ keyframe.viewPrev,
-                      /* .newChildShadowView = */ {},
-                      /* .index = */ mutation.index};
+                  executeMutationImmediately =
+                      ShadowViewMutation::RemoveMutation(
+                          mutation.parentShadowView,
+                          keyframe.viewPrev,
+                          mutation.index);
                 }
               }
             }
@@ -1274,18 +1274,31 @@ void LayoutAnimationKeyFrameManager::queueFinalMutationsForCompletedKeyFrame(
           logPrefix + ": Queuing up Final Mutation:", finalMutation);
       // Copy so that if something else mutates the inflight animations,
       // it won't change this mutation after this point.
-      auto mutation = ShadowViewMutation{
-          /* .type = */ finalMutation.type,
-          /* .parentShadowView = */ finalMutation.parentShadowView,
-          /* .oldChildShadowView = */ prev,
-          /* .newChildShadowView = */ finalMutation.newChildShadowView,
-          /* .index = */ finalMutation.index};
-      react_native_assert(mutation.oldChildShadowView.tag > 0);
-      react_native_assert(
-          mutation.newChildShadowView.tag > 0 ||
-          finalMutation.type == ShadowViewMutation::Remove ||
-          finalMutation.type == ShadowViewMutation::Delete);
-      mutationsList.push_back(mutation);
+      switch (finalMutation.type) {
+          // For CREATE/INSERT this will contain CREATE, INSERT in that order.
+          // For REMOVE/DELETE, same.
+        case ShadowViewMutation::Type::Create:
+          mutationsList.push_back(ShadowViewMutation::CreateMutation(
+              finalMutation.newChildShadowView));
+          break;
+        case ShadowViewMutation::Type::Delete:
+          mutationsList.push_back(ShadowViewMutation::DeleteMutation(prev));
+          break;
+        case ShadowViewMutation::Type::Insert:
+          mutationsList.push_back(ShadowViewMutation::InsertMutation(
+              finalMutation.parentShadowView,
+              finalMutation.newChildShadowView,
+              finalMutation.index));
+          break;
+        case ShadowViewMutation::Type::Remove:
+          mutationsList.push_back(ShadowViewMutation::RemoveMutation(
+              finalMutation.parentShadowView, prev, finalMutation.index));
+          break;
+        case ShadowViewMutation::Type::Update:
+          mutationsList.push_back(ShadowViewMutation::UpdateMutation(
+              prev, finalMutation.newChildShadowView));
+          break;
+      }
       if (finalMutation.newChildShadowView.tag > 0) {
         prev = finalMutation.newChildShadowView;
       }
@@ -1327,19 +1340,15 @@ void LayoutAnimationKeyFrameManager::queueFinalMutationsForCompletedKeyFrame(
           generatedMutation);
       mutationsList.push_back(generatedMutation);
     } else {
-      auto mutation = ShadowViewMutation{
-          /* .type = */ ShadowViewMutation::Type::Update,
-          /* .parentShadowView = */ keyframe.parentView,
-          /* .oldChildShadowView = */ keyframe.viewPrev,
-          /* .newChildShadowView = */ keyframe.viewEnd,
-          /* .index = */ -1};
+      auto mutation = ShadowViewMutation::UpdateMutation(
+          keyframe.viewPrev, keyframe.viewEnd);
       PrintMutationInstruction(
           logPrefix +
               "Animation Complete: Queuing up Final Synthetic Mutation:",
           mutation);
       react_native_assert(mutation.oldChildShadowView.tag > 0);
       react_native_assert(mutation.newChildShadowView.tag > 0);
-      mutationsList.push_back(mutation);
+      mutationsList.push_back(std::move(mutation));
     }
   }
 }

ReactCommon/react/renderer/mounting/ShadowViewMutation.cpp

@@ -84,6 +84,18 @@ bool ShadowViewMutation::mutatedViewIsVirtual() const {
   return viewIsVirtual;
 }
 
+ShadowViewMutation::ShadowViewMutation(
+    Type type,
+    ShadowView parentShadowView,
+    ShadowView oldChildShadowView,
+    ShadowView newChildShadowView,
+    int index)
+    : type(type),
+      parentShadowView(parentShadowView),
+      oldChildShadowView(oldChildShadowView),
+      newChildShadowView(newChildShadowView),
+      index(index) {}
+
 #if RN_DEBUG_STRING_CONVERTIBLE
 
 std::string getDebugName(ShadowViewMutation const &mutation) {

ReactCommon/react/renderer/mounting/ShadowViewMutation.h

@@ -23,6 +23,8 @@ namespace react {
 struct ShadowViewMutation final {
   using List = std::vector<ShadowViewMutation>;
 
+  ShadowViewMutation() = delete;
+
 #pragma mark - Designated Initializers
 
   /*
@@ -70,13 +72,20 @@ struct ShadowViewMutation final {
   ShadowView newChildShadowView = {};
   int index = -1;
 
- public:
   // Some platforms can have the notion of virtual views - views that are in the
   // ShadowTree hierarchy but never are on the platform. Generally this is used
   // so notify the platform that a view exists so that we can keep EventEmitters
   // around, to notify JS of something. This mechanism is DEPRECATED and it is
   // highly recommended that you NOT make use of this in your platform!
   bool mutatedViewIsVirtual() const;
+
+ private:
+  ShadowViewMutation(
+      Type type,
+      ShadowView parentShadowView,
+      ShadowView oldChildShadowView,
+      ShadowView newChildShadowView,
+      int index);
 };
 
 using ShadowViewMutationList = std::vector<ShadowViewMutation>;