layout/style/nsDOMCSSDeclaration.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
   7 /* base class for DOM objects for element.style and cssStyleRule.style */
   8
   9 #ifndef nsDOMCSSDeclaration_h___
  10 #define nsDOMCSSDeclaration_h___
  11
  12 #include "nsICSSDeclaration.h"
  13
  14 #include "mozilla/Attributes.h"
  15 #include "mozilla/Maybe.h"
  16 #include "mozilla/URLExtraData.h"
  17 #include "nsAttrValue.h"
  18 #include "nsCOMPtr.h"
  19 #include "nsCompatibility.h"
  20
  21 class nsIPrincipal;
  22 struct JSContext;
  23 class JSObject;
  24
  25 namespace mozilla {
  26 enum class StyleCssRuleType : uint8_t;
  27 class DeclarationBlock;
  28 struct DeclarationBlockMutationClosure;
  29 namespace css {
  30 class Loader;
  31 class Rule;
  32 }  // namespace css
  33 namespace dom {
  34 class Document;
  35 class Element;
  36 }  // namespace dom
  37
  38 struct MutationClosureData {
  39   MutationClosureData() = default;
  40
  41   mozilla::dom::Element* mElement = nullptr;
  42   Maybe<nsAttrValue> mOldValue;
  43   uint8_t mModType = 0;
  44   bool mWasCalled = false;
  45   bool mShouldBeCalled = false;
  46 };
  47
  48 }  // namespace mozilla
  49
  50 class nsDOMCSSDeclaration : public nsICSSDeclaration {
  51  public:
  52   // Only implement QueryInterface; subclasses have the responsibility
  53   // of implementing AddRef/Release.
  54   NS_IMETHOD QueryInterface(REFNSIID aIID, void** aInstancePtr) override;
  55
  56   // Declare addref and release so they can be called on us, but don't
  57   // implement them.  Our subclasses must handle their own
  58   // refcounting.
  59   NS_IMETHOD_(MozExternalRefCountType) AddRef() override = 0;
  60   NS_IMETHOD_(MozExternalRefCountType) Release() override = 0;
  61
  62   /**
  63    * Method analogous to CSSStyleDeclaration::GetPropertyValue,
  64    * which obeys all the same restrictions.
  65    */
  66   virtual void GetPropertyValue(const nsCSSPropertyID aPropID,
  67                                 nsACString& aValue);
  68
  69   /**
  70    * Method analogous to CSSStyleDeclaration::SetProperty.  This
  71    * method does NOT allow setting a priority (the priority will
  72    * always be set to default priority).
  73    */
  74   virtual void SetPropertyValue(const nsCSSPropertyID aPropID,
  75                                 const nsACString& aValue,
  76                                 nsIPrincipal* aSubjectPrincipal,
  77                                 mozilla::ErrorResult& aRv);
  78
  79   // Require subclasses to implement |GetParentRule|.
  80   // NS_DECL_NSIDOMCSSSTYLEDECLARATION
  81   void GetCssText(nsACString& aCssText) override;
  82   void SetCssText(const nsACString& aCssText, nsIPrincipal* aSubjectPrincipal,
  83                   mozilla::ErrorResult& aRv) override;
  84   void GetPropertyValue(const nsACString& propertyName,
  85                         nsACString& _retval) override;
  86   void RemoveProperty(const nsACString& propertyName, nsACString& _retval,
  87                       mozilla::ErrorResult& aRv) override;
  88   void GetPropertyPriority(const nsACString& propertyName,
  89                            nsACString& aPriority) override;
  90   void SetProperty(const nsACString& propertyName, const nsACString& value,
  91                    const nsACString& priority, nsIPrincipal* aSubjectPrincipal,
  92                    mozilla::ErrorResult& aRv) override;
  93   uint32_t Length() override;
  94
  95   // WebIDL interface for CSS2Properties
  96   virtual void IndexedGetter(uint32_t aIndex, bool& aFound,
  97                              nsACString& aPropName) override;
  98
  99   JSObject* WrapObject(JSContext*, JS::Handle<JSObject*> aGivenProto) override;
 100
 101   // Information needed to parse a declaration for Servo side.
 102   // Put this in public so other Servo parsing functions can reuse this.
 103   struct MOZ_STACK_CLASS ParsingEnvironment {
 104     RefPtr<mozilla::URLExtraData> mUrlExtraData;
 105     nsCompatibility mCompatMode = eCompatibility_FullStandards;
 106     mozilla::css::Loader* mLoader = nullptr;
 107     mozilla::StyleCssRuleType mRuleType{1 /* Style */};
 108   };
 109
 110  protected:
 111   // The reason for calling GetOrCreateCSSDeclaration.
 112   enum class Operation {
 113     // We are calling GetOrCreateCSSDeclaration so that we can read from it.
 114     // Does not allocate a new declaration if we don't have one yet; returns
 115     // nullptr in this case.
 116     Read,
 117
 118     // We are calling GetOrCreateCSSDeclaration so that we can set a property on
 119     // it or re-parse the whole declaration.  Allocates a new declaration if we
 120     // don't have one yet. A nullptr return value indicates an error allocating
 121     // the declaration.
 122     Modify,
 123
 124     // We are calling GetOrCreateCSSDeclaration so that we can remove a property
 125     // from it. Does not allocate a new declaration if we don't have one yet;
 126     // returns nullptr in this case.
 127     RemoveProperty,
 128   };
 129
 130   // If aOperation is Modify, aCreated must be non-null and the call may set it
 131   // to point to the newly created object.
 132   virtual mozilla::DeclarationBlock* GetOrCreateCSSDeclaration(
 133       Operation aOperation, mozilla::DeclarationBlock** aCreated) = 0;
 134
 135   virtual nsresult SetCSSDeclaration(
 136       mozilla::DeclarationBlock* aDecl,
 137       mozilla::MutationClosureData* aClosureData) = 0;
 138   // Document that we must call BeginUpdate/EndUpdate on around the
 139   // calls to SetCSSDeclaration and the style rule mutation that leads
 140   // to it.
 141   virtual mozilla::dom::Document* DocToUpdate() = 0;
 142
 143   // mUrlExtraData returns URL data for parsing url values in
 144   // CSS. Returns nullptr on failure. If mUrlExtraData is nullptr,
 145   // mCompatMode may not be set to anything meaningful.
 146   // If aSubjectPrincipal is passed, it should be the subject principal of the
 147   // scripted caller that initiated the parser.
 148   virtual ParsingEnvironment GetParsingEnvironment(
 149       nsIPrincipal* aSubjectPrincipal = nullptr) const = 0;
 150
 151   // An implementation for GetParsingEnvironment for callers wrapping a
 152   // css::Rule.
 153   //
 154   // The RuleType argument is just to avoid a virtual call, since all callers
 155   // know it statically. Should be equal to aRule->Type().
 156   static ParsingEnvironment GetParsingEnvironmentForRule(
 157       const mozilla::css::Rule* aRule, mozilla::StyleCssRuleType);
 158
 159   nsresult ParsePropertyValue(const nsCSSPropertyID aPropID,
 160                               const nsACString& aPropValue, bool aIsImportant,
 161                               nsIPrincipal* aSubjectPrincipal);
 162
 163   nsresult ParseCustomPropertyValue(const nsACString& aPropertyName,
 164                                     const nsACString& aPropValue,
 165                                     bool aIsImportant,
 166                                     nsIPrincipal* aSubjectPrincipal);
 167
 168   void RemovePropertyInternal(nsCSSPropertyID aPropID,
 169                               mozilla::ErrorResult& aRv);
 170   void RemovePropertyInternal(const nsACString& aPropert,
 171                               mozilla::ErrorResult& aRv);
 172
 173   virtual void GetPropertyChangeClosure(
 174       mozilla::DeclarationBlockMutationClosure* aClosure,
 175       mozilla::MutationClosureData* aClosureData) {}
 176
 177  protected:
 178   virtual ~nsDOMCSSDeclaration();
 179
 180  private:
 181   template <typename ServoFunc>
 182   inline nsresult ModifyDeclaration(nsIPrincipal* aSubjectPrincipal,
 183                                     mozilla::MutationClosureData* aClosureData,
 184                                     ServoFunc aServoFunc);
 185 };
 186
 187 #endif  // nsDOMCSSDeclaration_h___