Bug 1556095 - Make BindContext carry a bit more information. r=bzbarsky

This makes some callers a bit less awkward by not having, for example, to read
from the parent node or not depending on whether Element::BindToTree has been
called already or not.

Differential Revision: https://phabricator.services.mozilla.com/D33368

--HG--
extra : moz-landing-system : lando

dom/base/BindContext.h

@@ -24,6 +24,22 @@ struct MOZ_STACK_CLASS BindContext final {
   // OwnerDoc().
   Document& OwnerDoc() const { return mDoc; }
 
+  // Whether we're getting connected.
+  //
+  // https://dom.spec.whatwg.org/#connected
+  bool InComposedDoc() const { return mInComposedDoc; }
+
+  // Whether we're getting bound to the document tree.
+  //
+  // https://dom.spec.whatwg.org/#in-a-document-tree
+  bool InUncomposedDoc() const { return mInUncomposedDoc; }
+
+  Document* GetComposedDoc() const { return mInComposedDoc ? &mDoc : nullptr; }
+
+  Document* GetUncomposedDoc() const {
+    return mInUncomposedDoc ? &mDoc : nullptr;
+  }
+
   // Whether our subtree root is changing as a result of this operation.
   bool SubtreeRootChanges() const { return mSubtreeRootChanges; }
 
@@ -35,10 +51,12 @@ struct MOZ_STACK_CLASS BindContext final {
   // This constructor should be used for regular appends to content.
   explicit BindContext(nsINode& aParentNode)
       : mDoc(*aParentNode.OwnerDoc()),
-        mSubtreeRootChanges(true),
         mBindingParent(aParentNode.IsContent()
                            ? aParentNode.AsContent()->GetBindingParent()
-                           : nullptr) {}
+                           : nullptr),
+        mInComposedDoc(aParentNode.IsInComposedDoc()),
+        mInUncomposedDoc(aParentNode.IsInUncomposedDoc()),
+        mSubtreeRootChanges(true) {}
 
   // When re-binding a shadow host into a tree, we re-bind all the shadow tree
   // from the root. In that case, the shadow tree contents remain within the
@@ -48,30 +66,42 @@ struct MOZ_STACK_CLASS BindContext final {
   // This constructor is only meant to be used in that situation.
   explicit BindContext(ShadowRoot& aShadowRoot)
       : mDoc(*aShadowRoot.OwnerDoc()),
-        mSubtreeRootChanges(false),
-        mBindingParent(aShadowRoot.Host()) {}
+        mBindingParent(aShadowRoot.Host()),
+        mInComposedDoc(aShadowRoot.IsInComposedDoc()),
+        mInUncomposedDoc(false),
+        mSubtreeRootChanges(false) {}
 
   // This constructor is meant to be used when inserting native-anonymous
   // children into a subtree.
   enum ForNativeAnonymous { ForNativeAnonymous };
   BindContext(Element& aParentElement, enum ForNativeAnonymous)
       : mDoc(*aParentElement.OwnerDoc()),
-        mSubtreeRootChanges(true),
-        mBindingParent(&aParentElement) {}
+        mBindingParent(&aParentElement),
+        mInComposedDoc(aParentElement.IsInComposedDoc()),
+        mInUncomposedDoc(aParentElement.IsInUncomposedDoc()),
+        mSubtreeRootChanges(true) {
+    MOZ_ASSERT(mInComposedDoc, "Binding NAC in a disconnected subtree?");
+  }
 
   // This is meant to be used to bind XBL anonymous content.
   BindContext(nsXBLBinding& aBinding, Element& aParentElement)
       : mDoc(*aParentElement.OwnerDoc()),
-        mSubtreeRootChanges(true),
-        mBindingParent(aBinding.GetBoundElement()) {}
+        mBindingParent(aBinding.GetBoundElement()),
+        mInComposedDoc(aParentElement.IsInComposedDoc()),
+        mInUncomposedDoc(aParentElement.IsInUncomposedDoc()),
+        mSubtreeRootChanges(true) {}
 
  private:
   Document& mDoc;
 
+  Element* const mBindingParent;
+
+  const bool mInComposedDoc;
+  const bool mInUncomposedDoc;
+
   // Whether the bind operation will change the subtree root of the content
   // we're binding.
   const bool mSubtreeRootChanges;
-  Element* const mBindingParent;
 };
 
 }  // namespace dom

dom/base/CharacterData.cpp

@@ -481,6 +481,8 @@ nsresult CharacterData::BindToTree(BindContext& aContext, nsINode& aParent) {
   UpdateEditableState(false);
 
   MOZ_ASSERT(OwnerDoc() == aParent.OwnerDoc(), "Bound to wrong document");
+  MOZ_ASSERT(IsInComposedDoc() == aContext.InComposedDoc());
+  MOZ_ASSERT(IsInUncomposedDoc() == aContext.InUncomposedDoc());
   MOZ_ASSERT(&aParent == GetParentNode(), "Bound to wrong parent node");
   MOZ_ASSERT(aContext.GetBindingParent() == GetBindingParent(),
              "Bound to wrong binding parent");

dom/base/Element.cpp

@@ -1758,6 +1758,8 @@ nsresult Element::BindToTree(BindContext& aContext, nsINode& aParent) {
   // postcondition asserts....  But we do want that, since things will
   // generally be quite broken when that happens.
   MOZ_ASSERT(OwnerDoc() == aParent.OwnerDoc(), "Bound to wrong document");
+  MOZ_ASSERT(IsInComposedDoc() == aContext.InComposedDoc());
+  MOZ_ASSERT(IsInUncomposedDoc() == aContext.InUncomposedDoc());
   MOZ_ASSERT(&aParent == GetParentNode(), "Bound to wrong parent node");
   MOZ_ASSERT(aContext.GetBindingParent() == GetBindingParent(),
              "Bound to wrong binding parent");

dom/base/nsImageLoadingContent.cpp

@@ -13,6 +13,7 @@
 #include "nsImageLoadingContent.h"
 #include "nsError.h"
 #include "nsIContent.h"
+#include "mozilla/dom/BindContext.h"
 #include "mozilla/dom/Document.h"
 #include "nsIScriptGlobalObject.h"
 #include "nsIDOMWindow.h"
@@ -1613,8 +1614,7 @@ void nsImageLoadingContent::NotifyOwnerDocumentActivityChanged() {
 void nsImageLoadingContent::BindToTree(BindContext& aContext,
                                        nsINode& aParent) {
   // We may be getting connected, if so our image should be tracked,
-  // NOTE(emilio): Using aParent to avoid silly virtual call.
-  if (aParent.IsInComposedDoc()) {
+  if (aContext.InComposedDoc()) {
     TrackImage(mCurrentRequest);
     TrackImage(mPendingRequest);
   }

dom/base/nsObjectLoadingContent.cpp

@@ -567,10 +567,9 @@ already_AddRefed<nsIDocShell> nsObjectLoadingContent::SetupDocShell(
 nsresult nsObjectLoadingContent::BindToTree(BindContext& aContext,
                                             nsINode& aParent) {
   nsImageLoadingContent::BindToTree(aContext, aParent);
-  // NOTE(emilio): Using aParent to avoid silly QI.
   // FIXME(emilio): Should probably use composed doc?
-  if (aParent.IsInUncomposedDoc()) {
-    aContext.OwnerDoc().AddPlugin(this);
+  if (Document* doc = aContext.GetUncomposedDoc()) {
+    doc->AddPlugin(this);
   }
   return NS_OK;
 }

dom/mathml/nsMathMLElement.cpp

@@ -82,13 +82,13 @@ nsresult nsMathMLElement::BindToTree(BindContext& aContext, nsINode& aParent) {
 
   // FIXME(emilio): Probably should be composed, this uses all the other link
   // infrastructure.
-  if (IsInUncomposedDoc()) {
-    aContext.OwnerDoc().RegisterPendingLinkUpdate(this);
+  if (Document* doc = aContext.GetUncomposedDoc()) {
+    doc->RegisterPendingLinkUpdate(this);
   }
 
   // Set the bit in the document for telemetry.
-  if (IsInComposedDoc()) {
-    aContext.OwnerDoc().SetMathMLEnabled();
+  if (Document* doc = aContext.GetComposedDoc()) {
+    doc->SetMathMLEnabled();
   }
 
   return rv;

dom/svg/SVGAElement.cpp

@@ -161,8 +161,8 @@ nsresult SVGAElement::BindToTree(BindContext& aContext, nsINode& aParent) {
   nsresult rv = SVGAElementBase::BindToTree(aContext, aParent);
   NS_ENSURE_SUCCESS(rv, rv);
 
-  if (IsInComposedDoc()) {
-    aContext.OwnerDoc().RegisterPendingLinkUpdate(this);
+  if (Document* doc = aContext.GetComposedDoc()) {
+    doc->RegisterPendingLinkUpdate(this);
   }
 
   return NS_OK;

dom/svg/SVGAnimationElement.cpp

@@ -140,9 +140,8 @@ nsresult SVGAnimationElement::BindToTree(BindContext& aContext,
   NS_ENSURE_SUCCESS(rv, rv);
 
   // Add myself to the animation controller's master set of animation elements.
-  if (IsInComposedDoc()) {
-    if (SMILAnimationController* controller =
-            aContext.OwnerDoc().GetAnimationController()) {
+  if (Document* doc = aContext.GetComposedDoc()) {
+    if (SMILAnimationController* controller = doc->GetAnimationController()) {
       controller->RegisterAnimationElement(this);
     }
     const nsAttrValue* href =

dom/svg/SVGSVGElement.cpp

@@ -370,10 +370,9 @@ SMILTimeContainer* SVGSVGElement::GetTimedDocumentRoot() {
 nsresult SVGSVGElement::BindToTree(BindContext& aContext, nsINode& aParent) {
   SMILAnimationController* smilController = nullptr;
 
-  // NOTE(emilio): Using aParent because we still haven't called our base class.
-  // FIXME(emilio, bug 1555948): Should probably use IsInComposedDoc()?
-  if (aParent.IsInUncomposedDoc()) {
-    if ((smilController = aContext.OwnerDoc().GetAnimationController())) {
+  // FIXME(emilio, bug 1555948): Should probably use composed doc.
+  if (Document* doc = aContext.GetUncomposedDoc()) {
+    if ((smilController = doc->GetAnimationController())) {
       // SMIL is enabled in this document
       if (WillBeOutermostSVG(aParent, aContext.GetBindingParent())) {
         // We'll be the outermost <svg> element.  We'll need a time container.