1 files changed, 101 insertions, 0 deletions
diff --git a/dom/base/BindContext.h b/dom/base/BindContext.h
new file mode 100644
index 0000000000..4ad0d7d9eb
--- /dev/null
+++ b/dom/base/BindContext.h
@@ -0,0 +1,101 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/* State that is passed down to BindToTree. */
+
+#ifndef mozilla_dom_BindContext_h__
+#define mozilla_dom_BindContext_h__
+
+#include "mozilla/Attributes.h"
+#include "mozilla/dom/Element.h"
+#include "mozilla/dom/ShadowRoot.h"
+#include "nsINode.h"
+
+namespace mozilla::dom {
+
+class Document;
+
+struct MOZ_STACK_CLASS BindContext final {
+  // The document that owns the tree we're getting bound to.
+  //
+  // This is mostly an optimization to avoid silly pointer-chases to get the
+  // 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; }
+
+  // Autofocus is allowed only if the is in the same origin as the top level
+  // document.
+  // https://html.spec.whatwg.org/multipage/interaction.html#the-autofocus-attribute:same-origin
+  // In addition, the document should not be already loaded and the
+  // "browser.autofocus" preference should be 'true'.
+  bool AllowsAutoFocus() const;
+
+  // This constructor should be used for regular appends to content.
+  explicit BindContext(nsINode& aParent)
+      : mDoc(*aParent.OwnerDoc()),
+        mInComposedDoc(aParent.IsInComposedDoc()),
+        mInUncomposedDoc(aParent.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
+  // same subtree root.  So children should avoid doing silly things like adding
+  // themselves to the ShadowRoot's id table twice or what not.
+  //
+  // This constructor is only meant to be used in that situation.
+  explicit BindContext(ShadowRoot& aShadowRoot)
+      : mDoc(*aShadowRoot.OwnerDoc()),
+        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()),
+        mInComposedDoc(aParentElement.IsInComposedDoc()),
+        mInUncomposedDoc(aParentElement.IsInUncomposedDoc()),
+        mSubtreeRootChanges(true) {
+    MOZ_ASSERT(mInComposedDoc, "Binding NAC in a disconnected subtree?");
+  }
+
+ private:
+  // Returns true iff the document is in the same origin as the top level
+  // document.
+  bool IsSameOriginAsTop() const;
+
+  Document& mDoc;
+
+  const bool mInComposedDoc;
+  const bool mInUncomposedDoc;
+
+  // Whether the bind operation will change the subtree root of the content
+  // we're binding.
+  const bool mSubtreeRootChanges;
+};
+
+}  // namespace mozilla::dom
+
+#endif