dom/base/nsStyledElement.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 /**
   8  * nsStyledElement is the base for elements supporting styling via the
   9  * id/class/style attributes; it is a common base for their support in HTML,
  10  * SVG and MathML.
  11  */
  12
  13 #ifndef __NS_STYLEDELEMENT_H_
  14 #define __NS_STYLEDELEMENT_H_
  15
  16 #include "mozilla/Attributes.h"
  17 #include "mozilla/dom/Element.h"
  18 #include "nsString.h"
  19
  20 namespace mozilla {
  21 class DeclarationBlock;
  22 struct MutationClosureData;
  23 }  // namespace mozilla
  24
  25 // IID for nsStyledElement interface
  26 #define NS_STYLED_ELEMENT_IID                        \
  27   {                                                  \
  28     0xacbd9ea6, 0x15aa, 0x4f37, {                    \
  29       0x8c, 0xe0, 0x35, 0x1e, 0xd7, 0x21, 0xca, 0xe9 \
  30     }                                                \
  31   }
  32
  33 using nsStyledElementBase = mozilla::dom::Element;
  34
  35 class nsStyledElement : public nsStyledElementBase {
  36  protected:
  37   inline explicit nsStyledElement(
  38       already_AddRefed<mozilla::dom::NodeInfo>&& aNodeInfo)
  39       : nsStyledElementBase(std::move(aNodeInfo)) {}
  40
  41  public:
  42   // We don't want to implement AddRef/Release because that would add an extra
  43   // function call for those on pretty much all elements.  But we do need QI, so
  44   // we can QI to nsStyledElement.
  45   NS_IMETHOD QueryInterface(REFNSIID aIID, void** aInstancePtr) override;
  46
  47   // Element interface methods
  48   virtual void InlineStyleDeclarationWillChange(
  49       mozilla::MutationClosureData& aData) override;
  50   virtual nsresult SetInlineStyleDeclaration(
  51       mozilla::DeclarationBlock& aDeclaration,
  52       mozilla::MutationClosureData& aData) override;
  53   virtual nsresult BindToTree(BindContext& aContext, nsINode& aParent) override;
  54
  55   nsICSSDeclaration* Style();
  56
  57   NS_DECLARE_STATIC_IID_ACCESSOR(NS_STYLED_ELEMENT_IID)
  58   NS_IMPL_FROMNODE_HELPER(nsStyledElement, IsStyledElement());
  59
  60   bool IsStyledElement() const final { return true; }
  61
  62  protected:
  63   nsICSSDeclaration* GetExistingStyle();
  64
  65   /**
  66    * Parse a style attr value into a CSS rulestruct (or, if there is no
  67    * document, leave it as a string) and return as nsAttrValue.
  68    *
  69    * @param aValue the value to parse
  70    * @param aMaybeScriptedPrincipal if available, the scripted principal
  71    *        responsible for this attribute value, as passed to
  72    *        Element::ParseAttribute.
  73    * @param aResult the resulting HTMLValue [OUT]
  74    */
  75   void ParseStyleAttribute(const nsAString& aValue,
  76                            nsIPrincipal* aMaybeScriptedPrincipal,
  77                            nsAttrValue& aResult, bool aForceInDataDoc);
  78
  79   bool ParseAttribute(int32_t aNamespaceID, nsAtom* aAttribute,
  80                       const nsAString& aValue,
  81                       nsIPrincipal* aMaybeScriptedPrincipal,
  82                       nsAttrValue& aResult) override;
  83
  84   friend class mozilla::dom::Element;
  85
  86   /**
  87    * Create the style struct from the style attr.  Used when an element is
  88    * first put into a document.  Only has an effect if the old value is a
  89    * string.  If aForceInDataDoc is true, will reparse even if we're in a data
  90    * document.
  91    */
  92   nsresult ReparseStyleAttribute(bool aForceInDataDoc);
  93
  94   void BeforeSetAttr(int32_t aNamespaceID, nsAtom* aName,
  95                      const nsAttrValue* aValue, bool aNotify) override;
  96 };
  97
  98 NS_DEFINE_STATIC_IID_ACCESSOR(nsStyledElement, NS_STYLED_ELEMENT_IID)
  99 #endif  // __NS_STYLEDELEMENT_H_