From 3a97503b361b0b5ff1b5d8948a74497710f2a095 Mon Sep 17 00:00:00 2001
From: Gaming4JC <g4jc@hyperbola.info>
Date: Thu, 2 Jan 2020 22:04:11 -0500
Subject: Bug 1309184 - Implement upgrade reaction for custom element
 reactions.

Tag UXP Issue #1344
---
 dom/base/CustomElementRegistry.h | 110 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 110 insertions(+)

(limited to 'dom/base/CustomElementRegistry.h')

diff --git a/dom/base/CustomElementRegistry.h b/dom/base/CustomElementRegistry.h
index 8ef0785af..b3b4d7c0f 100644
--- a/dom/base/CustomElementRegistry.h
+++ b/dom/base/CustomElementRegistry.h
@@ -134,6 +134,37 @@ struct CustomElementDefinition
   }
 };
 
+class CustomElementReaction
+{
+public:
+  explicit CustomElementReaction(CustomElementRegistry* aRegistry,
+                                 CustomElementDefinition* aDefinition)
+    : mRegistry(aRegistry)
+    , mDefinition(aDefinition)
+  {
+  };
+
+  virtual ~CustomElementReaction() = default;
+  virtual void Invoke(Element* aElement) = 0;
+
+protected:
+  CustomElementRegistry* mRegistry;
+  CustomElementDefinition* mDefinition;
+};
+
+class CustomElementUpgradeReaction final : public CustomElementReaction
+{
+public:
+  explicit CustomElementUpgradeReaction(CustomElementRegistry* aRegistry,
+                                        CustomElementDefinition* aDefinition)
+    : CustomElementReaction(aRegistry, aDefinition)
+  {
+  }
+
+private:
+   virtual void Invoke(Element* aElement) override;
+};
+
 class CustomElementRegistry final : public nsISupports,
                                     public nsWrapperCache
 {
@@ -177,6 +208,24 @@ public:
   void GetCustomPrototype(nsIAtom* aAtom,
                           JS::MutableHandle<JSObject*> aPrototype);
 
+  /**
+   * Enqueue a custom element upgrade reaction
+   * https://html.spec.whatwg.org/multipage/scripting.html#enqueue-a-custom-element-upgrade-reaction
+   */
+  void EnqueueUpgradeReaction(Element* aElement,
+                              CustomElementDefinition* aDefinition);
+
+  void Upgrade(Element* aElement, CustomElementDefinition* aDefinition);
+
+  // [CEReactions] Before executing the algorithm's steps
+  // Push a new element queue onto the custom element reactions stack.
+  void CreateAndPushElementQueue();
+
+  // [CEReactions] After executing the algorithm's steps
+  // Pop the element queue from the custom element reactions stack,
+  // and invoke custom element reactions in that queue.
+  void PopAndInvokeElementQueue();
+
 private:
   explicit CustomElementRegistry(nsPIDOMWindowInner* aWindow);
   ~CustomElementRegistry();
@@ -198,6 +247,21 @@ private:
                          nsIAtom* aKey,
                          CustomElementDefinition* aDefinition);
 
+  void InvokeBackupQueue();
+
+  void Enqueue(Element* aElement, CustomElementReaction* aReaction);
+
+  // nsWeakPtr is a weak pointer of Element
+  // The element reaction queues are stored in ElementReactionQueueMap.
+  // We need to lookup ElementReactionQueueMap again to get relevant reaction queue.
+  typedef nsTArray<nsWeakPtr> ElementQueue;
+
+  /**
+   * Invoke custom element reactions
+   * https://html.spec.whatwg.org/multipage/scripting.html#invoke-custom-element-reactions
+   */
+  void InvokeReactions(ElementQueue& aElementQueue);
+
   typedef nsClassHashtable<nsISupportsHashKey, CustomElementDefinition>
     DefinitionMap;
   typedef nsClassHashtable<nsISupportsHashKey, nsTArray<nsWeakPtr>>
@@ -238,6 +302,17 @@ private:
 
   // It is used to prevent reentrant invocations of element definition.
   bool mIsCustomDefinitionRunning;
+  // https://html.spec.whatwg.org/#enqueue-an-element-on-the-appropriate-element-queue
+  bool mIsBackupQueueProcessing;
+
+  typedef nsTArray<nsAutoPtr<CustomElementReaction>> ReactionQueue;
+  typedef nsClassHashtable<nsISupportsHashKey, ReactionQueue>
+    ElementReactionQueueMap;
+
+  ElementReactionQueueMap mElementReactionQueueMap;
+
+  nsTArray<ElementQueue> mReactionsStack;
+  ElementQueue mBackupQueue;
 
 private:
   class MOZ_RAII AutoSetRunningFlag final {
@@ -258,6 +333,28 @@ private:
       CustomElementRegistry* mRegistry;
   };
 
+private:
+  class ProcessBackupQueueRunnable : public mozilla::Runnable {
+    public:
+      explicit ProcessBackupQueueRunnable(CustomElementRegistry* aRegistry)
+        : mRegistry(aRegistry)
+      {
+        MOZ_ASSERT(!mRegistry->mIsBackupQueueProcessing,
+                   "mIsBackupQueueProcessing should be initially false");
+        mRegistry->mIsBackupQueueProcessing = true;
+      }
+
+      NS_IMETHOD Run() override
+      {
+        mRegistry->InvokeBackupQueue();
+        mRegistry->mIsBackupQueueProcessing = false;
+        return NS_OK;
+      }
+
+    private:
+      RefPtr<CustomElementRegistry> mRegistry;
+  };
+
 public:
   nsISupports* GetParentObject() const;
 
@@ -272,6 +369,19 @@ public:
   already_AddRefed<Promise> WhenDefined(const nsAString& aName, ErrorResult& aRv);
 };
 
+class MOZ_RAII AutoCEReaction final {
+  public:
+    explicit AutoCEReaction(CustomElementRegistry* aRegistry)
+      : mRegistry(aRegistry) {
+      mRegistry->CreateAndPushElementQueue();
+    }
+    ~AutoCEReaction() {
+      mRegistry->PopAndInvokeElementQueue();
+    }
+  private:
+    RefPtr<CustomElementRegistry> mRegistry;
+};
+
 } // namespace dom
 } // namespace mozilla
 
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