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