dom/base/LinkStyle.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6 #ifndef mozilla_dom_LinkStyle_h
   7 #define mozilla_dom_LinkStyle_h
   8
   9 #include "nsINode.h"
  10 #include "mozilla/Attributes.h"
  11 #include "mozilla/StyleSheet.h"
  12 #include "mozilla/Result.h"
  13 #include "mozilla/Unused.h"
  14 #include "nsTArray.h"
  15
  16 class nsIContent;
  17 class nsICSSLoaderObserver;
  18 class nsIPrincipal;
  19 class nsIURI;
  20
  21 namespace mozilla::dom {
  22
  23 class Document;
  24 enum class FetchPriority : uint8_t;
  25 class ShadowRoot;
  26
  27 // https://drafts.csswg.org/cssom/#the-linkstyle-interface
  28 class LinkStyle {
  29  public:
  30   enum class ForceUpdate : uint8_t {
  31     No,
  32     Yes,
  33   };
  34
  35   enum class Completed : uint8_t {
  36     No,
  37     Yes,
  38   };
  39
  40   enum class HasAlternateRel : uint8_t {
  41     No,
  42     Yes,
  43   };
  44
  45   enum class IsAlternate : uint8_t {
  46     No,
  47     Yes,
  48   };
  49
  50   enum class IsInline : uint8_t {
  51     No,
  52     Yes,
  53   };
  54
  55   enum class IsExplicitlyEnabled : uint8_t {
  56     No,
  57     Yes,
  58   };
  59
  60   enum class MediaMatched : uint8_t {
  61     Yes,
  62     No,
  63   };
  64
  65   struct Update {
  66    private:
  67     bool mWillNotify;
  68     bool mIsAlternate;
  69     bool mMediaMatched;
  70
  71    public:
  72     Update() : mWillNotify(false), mIsAlternate(false), mMediaMatched(false) {}
  73
  74     Update(Completed aCompleted, IsAlternate aIsAlternate,
  75            MediaMatched aMediaMatched)
  76         : mWillNotify(aCompleted == Completed::No),
  77           mIsAlternate(aIsAlternate == IsAlternate::Yes),
  78           mMediaMatched(aMediaMatched == MediaMatched::Yes) {}
  79
  80     bool WillNotify() const { return mWillNotify; }
  81
  82     bool ShouldBlock() const {
  83       if (!mWillNotify) {
  84         return false;
  85       }
  86
  87       return !mIsAlternate && mMediaMatched;
  88     }
  89   };
  90
  91   static LinkStyle* FromNode(nsINode& aNode) { return aNode.AsLinkStyle(); }
  92   static const LinkStyle* FromNode(const nsINode& aNode) {
  93     return aNode.AsLinkStyle();
  94   }
  95
  96   static LinkStyle* FromNode(Element&);
  97   static const LinkStyle* FromNode(const Element& aElement) {
  98     return FromNode(const_cast<Element&>(aElement));
  99   }
 100
 101   template <typename T>
 102   static LinkStyle* FromNodeOrNull(T* aNode) {
 103     return aNode ? FromNode(*aNode) : nullptr;
 104   }
 105
 106   template <typename T>
 107   static const LinkStyle* FromNodeOrNull(const T* aNode) {
 108     return aNode ? FromNode(*aNode) : nullptr;
 109   }
 110
 111   enum RelValue {
 112     ePREFETCH = 0x00000001,
 113     eDNS_PREFETCH = 0x00000002,
 114     eSTYLESHEET = 0x00000004,
 115     eNEXT = 0x00000008,
 116     eALTERNATE = 0x00000010,
 117     ePRECONNECT = 0x00000020,
 118     // NOTE: 0x40 is unused
 119     ePRELOAD = 0x00000080,
 120     eMODULE_PRELOAD = 0x00000100
 121   };
 122
 123   // The return value is a bitwise or of 0 or more RelValues.
 124   static uint32_t ParseLinkTypes(const nsAString& aTypes);
 125
 126   void UpdateStyleSheetInternal() {
 127     Unused << UpdateStyleSheetInternal(nullptr, nullptr);
 128   }
 129
 130   struct MOZ_STACK_CLASS SheetInfo {
 131     nsIContent* mContent;
 132     // FIXME(emilio): do these really need to be strong refs?
 133     nsCOMPtr<nsIURI> mURI;
 134
 135     // The principal of the scripted caller that initiated the load, if
 136     // available. Otherwise null.
 137     nsCOMPtr<nsIPrincipal> mTriggeringPrincipal;
 138     nsCOMPtr<nsIReferrerInfo> mReferrerInfo;
 139     mozilla::CORSMode mCORSMode;
 140     nsString mTitle;
 141     nsString mMedia;
 142     nsString mIntegrity;
 143     nsString mNonce;
 144     const FetchPriority mFetchPriority;
 145
 146     bool mHasAlternateRel;
 147     bool mIsInline;
 148     IsExplicitlyEnabled mIsExplicitlyEnabled;
 149
 150     SheetInfo(const mozilla::dom::Document&, nsIContent*,
 151               already_AddRefed<nsIURI> aURI,
 152               already_AddRefed<nsIPrincipal> aTriggeringPrincipal,
 153               already_AddRefed<nsIReferrerInfo> aReferrerInfo,
 154               mozilla::CORSMode, const nsAString& aTitle,
 155               const nsAString& aMedia, const nsAString& aIntegrity,
 156               const nsAString& aNonce, HasAlternateRel, IsInline,
 157               IsExplicitlyEnabled, FetchPriority aFetchPriority);
 158
 159     ~SheetInfo();
 160   };
 161
 162   virtual nsIContent& AsContent() = 0;
 163   virtual Maybe<SheetInfo> GetStyleSheetInfo() = 0;
 164
 165   /**
 166    * Used to make the association between a style sheet and
 167    * the element that linked it to the document.
 168    *
 169    * @param aStyleSheet the style sheet associated with this
 170    *                    element.
 171    */
 172   void SetStyleSheet(StyleSheet* aStyleSheet);
 173
 174   /**
 175    * Tells this element whether to update the stylesheet when the element's
 176    * properties change. This is used by the parser until it has all content etc,
 177    * and to guarantee that the right observer is used.
 178    */
 179   void DisableUpdates() { mUpdatesEnabled = false; }
 180   Result<Update, nsresult> EnableUpdatesAndUpdateStyleSheet(
 181       nsICSSLoaderObserver* aObserver) {
 182     MOZ_ASSERT(!mUpdatesEnabled);
 183     mUpdatesEnabled = true;
 184     return DoUpdateStyleSheet(nullptr, nullptr, aObserver, ForceUpdate::No);
 185   }
 186
 187   /**
 188    * Gets the charset that the element claims the style sheet is in.
 189    * Can return empty string to indicate that we have no charset
 190    * information.
 191    *
 192    * @param aCharset the charset
 193    */
 194   virtual void GetCharset(nsAString& aCharset);
 195
 196   // This doesn't entirely belong here since they only make sense for
 197   // some types of linking elements, but it's a better place than
 198   // anywhere else.
 199   void SetLineNumber(uint32_t aLineNumber) { mLineNumber = aLineNumber; }
 200
 201   /**
 202    * Get the line number, as previously set by SetLineNumber.
 203    *
 204    * @return the line number of this element; or 1 if no line number
 205    *         was set
 206    */
 207   uint32_t GetLineNumber() const { return mLineNumber; }
 208
 209   // This doesn't entirely belong here since they only make sense for
 210   // some types of linking elements, but it's a better place than
 211   // anywhere else.
 212   void SetColumnNumber(uint32_t aColumnNumber) {
 213     mColumnNumber = aColumnNumber;
 214   }
 215
 216   /**
 217    * Get the column number, as previously set by SetColumnNumber.
 218    *
 219    * @return the column number of this element; or 1 if no column number
 220    *         was set
 221    */
 222   uint32_t GetColumnNumber() const { return mColumnNumber; }
 223
 224   StyleSheet* GetSheet() const { return mStyleSheet; }
 225
 226   /** JS can only observe the sheet once fully loaded */
 227   StyleSheet* GetSheetForBindings() const;
 228
 229  protected:
 230   LinkStyle();
 231   virtual ~LinkStyle();
 232
 233   // Gets a suitable title and media for SheetInfo out of an element, which
 234   // needs to be `this`.
 235   //
 236   // NOTE(emilio): Needs nsString instead of nsAString because of
 237   // CompressWhitespace.
 238   static void GetTitleAndMediaForElement(const mozilla::dom::Element&,
 239                                          nsString& aTitle, nsString& aMedia);
 240
 241   // Returns whether the type attribute specifies the text/css type for style
 242   // elements.
 243   static bool IsCSSMimeTypeAttributeForStyleElement(const Element&);
 244
 245   // CC methods
 246   void Unlink();
 247   void Traverse(nsCycleCollectionTraversalCallback& cb);
 248
 249   /**
 250    * @param aOldDocument   should be non-null only if we're updating because we
 251    *                       removed the node from the document.
 252    * @param aOldShadowRoot should be non-null only if we're updating because we
 253    *                       removed the node from a shadow tree.
 254    * @param aForceUpdate true will force the update even if the URI has not
 255    *                     changed.  This should be used in cases when something
 256    *                     about the content that affects the resulting sheet
 257    *                     changed but the URI may not have changed.
 258    *
 259    * TODO(emilio): Should probably pass a single DocumentOrShadowRoot.
 260    */
 261   Result<Update, nsresult> UpdateStyleSheetInternal(
 262       Document* aOldDocument, ShadowRoot* aOldShadowRoot,
 263       ForceUpdate = ForceUpdate::No);
 264
 265   /**
 266    * @param aOldDocument should be non-null only if we're updating because we
 267    *                     removed the node from the document.
 268    * @param aOldShadowRoot The ShadowRoot that used to contain the style.
 269    *                     Passed as a parameter because on an update, the node
 270    *                     is removed from the tree before the sheet is removed
 271    *                     from the ShadowRoot.
 272    * @param aForceUpdate true will force the update even if the URI has not
 273    *                     changed.  This should be used in cases when something
 274    *                     about the content that affects the resulting sheet
 275    *                     changed but the URI may not have changed.
 276    */
 277   Result<Update, nsresult> DoUpdateStyleSheet(Document* aOldDocument,
 278                                               ShadowRoot* aOldShadowRoot,
 279                                               nsICSSLoaderObserver*,
 280                                               ForceUpdate);
 281
 282   void BindToTree();
 283
 284   RefPtr<mozilla::StyleSheet> mStyleSheet;
 285   nsCOMPtr<nsIPrincipal> mTriggeringPrincipal;
 286   bool mUpdatesEnabled = true;
 287   uint32_t mLineNumber = 1;
 288   uint32_t mColumnNumber = 1;
 289 };
 290
 291 }  // namespace mozilla::dom
 292
 293 #endif  // mozilla_dom_LinkStyle_h