1 files changed, 293 insertions, 0 deletions
diff --git a/dom/base/LinkStyle.h b/dom/base/LinkStyle.h
new file mode 100644
index 0000000000..d62ab8f4e1
--- /dev/null
+++ b/dom/base/LinkStyle.h
@@ -0,0 +1,293 @@
+/* -*- 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/. */
+#ifndef mozilla_dom_LinkStyle_h
+#define mozilla_dom_LinkStyle_h
+
+#include "nsINode.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/StyleSheet.h"
+#include "mozilla/Result.h"
+#include "mozilla/Unused.h"
+#include "nsTArray.h"
+
+class nsIContent;
+class nsICSSLoaderObserver;
+class nsIPrincipal;
+class nsIURI;
+
+namespace mozilla::dom {
+
+class Document;
+enum class FetchPriority : uint8_t;
+class ShadowRoot;
+
+// https://drafts.csswg.org/cssom/#the-linkstyle-interface
+class LinkStyle {
+ public:
+  enum class ForceUpdate : uint8_t {
+    No,
+    Yes,
+  };
+
+  enum class Completed : uint8_t {
+    No,
+    Yes,
+  };
+
+  enum class HasAlternateRel : uint8_t {
+    No,
+    Yes,
+  };
+
+  enum class IsAlternate : uint8_t {
+    No,
+    Yes,
+  };
+
+  enum class IsInline : uint8_t {
+    No,
+    Yes,
+  };
+
+  enum class IsExplicitlyEnabled : uint8_t {
+    No,
+    Yes,
+  };
+
+  enum class MediaMatched : uint8_t {
+    Yes,
+    No,
+  };
+
+  struct Update {
+   private:
+    bool mWillNotify;
+    bool mIsAlternate;
+    bool mMediaMatched;
+
+   public:
+    Update() : mWillNotify(false), mIsAlternate(false), mMediaMatched(false) {}
+
+    Update(Completed aCompleted, IsAlternate aIsAlternate,
+           MediaMatched aMediaMatched)
+        : mWillNotify(aCompleted == Completed::No),
+          mIsAlternate(aIsAlternate == IsAlternate::Yes),
+          mMediaMatched(aMediaMatched == MediaMatched::Yes) {}
+
+    bool WillNotify() const { return mWillNotify; }
+
+    bool ShouldBlock() const {
+      if (!mWillNotify) {
+        return false;
+      }
+
+      return !mIsAlternate && mMediaMatched;
+    }
+  };
+
+  static LinkStyle* FromNode(nsINode& aNode) { return aNode.AsLinkStyle(); }
+  static const LinkStyle* FromNode(const nsINode& aNode) {
+    return aNode.AsLinkStyle();
+  }
+
+  static LinkStyle* FromNode(Element&);
+  static const LinkStyle* FromNode(const Element& aElement) {
+    return FromNode(const_cast<Element&>(aElement));
+  }
+
+  template <typename T>
+  static LinkStyle* FromNodeOrNull(T* aNode) {
+    return aNode ? FromNode(*aNode) : nullptr;
+  }
+
+  template <typename T>
+  static const LinkStyle* FromNodeOrNull(const T* aNode) {
+    return aNode ? FromNode(*aNode) : nullptr;
+  }
+
+  enum RelValue {
+    ePREFETCH = 0x00000001,
+    eDNS_PREFETCH = 0x00000002,
+    eSTYLESHEET = 0x00000004,
+    eNEXT = 0x00000008,
+    eALTERNATE = 0x00000010,
+    ePRECONNECT = 0x00000020,
+    // NOTE: 0x40 is unused
+    ePRELOAD = 0x00000080,
+    eMODULE_PRELOAD = 0x00000100
+  };
+
+  // The return value is a bitwise or of 0 or more RelValues.
+  static uint32_t ParseLinkTypes(const nsAString& aTypes);
+
+  void UpdateStyleSheetInternal() {
+    Unused << UpdateStyleSheetInternal(nullptr, nullptr);
+  }
+
+  struct MOZ_STACK_CLASS SheetInfo {
+    nsIContent* mContent;
+    // FIXME(emilio): do these really need to be strong refs?
+    nsCOMPtr<nsIURI> mURI;
+
+    // The principal of the scripted caller that initiated the load, if
+    // available. Otherwise null.
+    nsCOMPtr<nsIPrincipal> mTriggeringPrincipal;
+    nsCOMPtr<nsIReferrerInfo> mReferrerInfo;
+    mozilla::CORSMode mCORSMode;
+    nsString mTitle;
+    nsString mMedia;
+    nsString mIntegrity;
+    nsString mNonce;
+    const FetchPriority mFetchPriority;
+
+    bool mHasAlternateRel;
+    bool mIsInline;
+    IsExplicitlyEnabled mIsExplicitlyEnabled;
+
+    SheetInfo(const mozilla::dom::Document&, nsIContent*,
+              already_AddRefed<nsIURI> aURI,
+              already_AddRefed<nsIPrincipal> aTriggeringPrincipal,
+              already_AddRefed<nsIReferrerInfo> aReferrerInfo,
+              mozilla::CORSMode, const nsAString& aTitle,
+              const nsAString& aMedia, const nsAString& aIntegrity,
+              const nsAString& aNonce, HasAlternateRel, IsInline,
+              IsExplicitlyEnabled, FetchPriority aFetchPriority);
+
+    ~SheetInfo();
+  };
+
+  virtual nsIContent& AsContent() = 0;
+  virtual Maybe<SheetInfo> GetStyleSheetInfo() = 0;
+
+  /**
+   * Used to make the association between a style sheet and
+   * the element that linked it to the document.
+   *
+   * @param aStyleSheet the style sheet associated with this
+   *                    element.
+   */
+  void SetStyleSheet(StyleSheet* aStyleSheet);
+
+  /**
+   * Tells this element whether to update the stylesheet when the element's
+   * properties change. This is used by the parser until it has all content etc,
+   * and to guarantee that the right observer is used.
+   */
+  void DisableUpdates() { mUpdatesEnabled = false; }
+  Result<Update, nsresult> EnableUpdatesAndUpdateStyleSheet(
+      nsICSSLoaderObserver* aObserver) {
+    MOZ_ASSERT(!mUpdatesEnabled);
+    mUpdatesEnabled = true;
+    return DoUpdateStyleSheet(nullptr, nullptr, aObserver, ForceUpdate::No);
+  }
+
+  /**
+   * Gets the charset that the element claims the style sheet is in.
+   * Can return empty string to indicate that we have no charset
+   * information.
+   *
+   * @param aCharset the charset
+   */
+  virtual void GetCharset(nsAString& aCharset);
+
+  // This doesn't entirely belong here since they only make sense for
+  // some types of linking elements, but it's a better place than
+  // anywhere else.
+  void SetLineNumber(uint32_t aLineNumber) { mLineNumber = aLineNumber; }
+
+  /**
+   * Get the line number, as previously set by SetLineNumber.
+   *
+   * @return the line number of this element; or 1 if no line number
+   *         was set
+   */
+  uint32_t GetLineNumber() const { return mLineNumber; }
+
+  // This doesn't entirely belong here since they only make sense for
+  // some types of linking elements, but it's a better place than
+  // anywhere else.
+  void SetColumnNumber(uint32_t aColumnNumber) {
+    mColumnNumber = aColumnNumber;
+  }
+
+  /**
+   * Get the column number, as previously set by SetColumnNumber.
+   *
+   * @return the column number of this element; or 1 if no column number
+   *         was set
+   */
+  uint32_t GetColumnNumber() const { return mColumnNumber; }
+
+  StyleSheet* GetSheet() const { return mStyleSheet; }
+
+  /** JS can only observe the sheet once fully loaded */
+  StyleSheet* GetSheetForBindings() const;
+
+ protected:
+  LinkStyle();
+  virtual ~LinkStyle();
+
+  // Gets a suitable title and media for SheetInfo out of an element, which
+  // needs to be `this`.
+  //
+  // NOTE(emilio): Needs nsString instead of nsAString because of
+  // CompressWhitespace.
+  static void GetTitleAndMediaForElement(const mozilla::dom::Element&,
+                                         nsString& aTitle, nsString& aMedia);
+
+  // Returns whether the type attribute specifies the text/css type for style
+  // elements.
+  static bool IsCSSMimeTypeAttributeForStyleElement(const Element&);
+
+  // CC methods
+  void Unlink();
+  void Traverse(nsCycleCollectionTraversalCallback& cb);
+
+  /**
+   * @param aOldDocument   should be non-null only if we're updating because we
+   *                       removed the node from the document.
+   * @param aOldShadowRoot should be non-null only if we're updating because we
+   *                       removed the node from a shadow tree.
+   * @param aForceUpdate true will force the update even if the URI has not
+   *                     changed.  This should be used in cases when something
+   *                     about the content that affects the resulting sheet
+   *                     changed but the URI may not have changed.
+   *
+   * TODO(emilio): Should probably pass a single DocumentOrShadowRoot.
+   */
+  Result<Update, nsresult> UpdateStyleSheetInternal(
+      Document* aOldDocument, ShadowRoot* aOldShadowRoot,
+      ForceUpdate = ForceUpdate::No);
+
+  /**
+   * @param aOldDocument should be non-null only if we're updating because we
+   *                     removed the node from the document.
+   * @param aOldShadowRoot The ShadowRoot that used to contain the style.
+   *                     Passed as a parameter because on an update, the node
+   *                     is removed from the tree before the sheet is removed
+   *                     from the ShadowRoot.
+   * @param aForceUpdate true will force the update even if the URI has not
+   *                     changed.  This should be used in cases when something
+   *                     about the content that affects the resulting sheet
+   *                     changed but the URI may not have changed.
+   */
+  Result<Update, nsresult> DoUpdateStyleSheet(Document* aOldDocument,
+                                              ShadowRoot* aOldShadowRoot,
+                                              nsICSSLoaderObserver*,
+                                              ForceUpdate);
+
+  void BindToTree();
+
+  RefPtr<mozilla::StyleSheet> mStyleSheet;
+  nsCOMPtr<nsIPrincipal> mTriggeringPrincipal;
+  bool mUpdatesEnabled = true;
+  uint32_t mLineNumber = 1;
+  uint32_t mColumnNumber = 1;
+};
+
+}  // namespace mozilla::dom
+
+#endif  // mozilla_dom_LinkStyle_h