gecko-dev/layout/style/nsCSSParser.h

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/* parsing of CSS stylesheets, based on a token stream from the CSS scanner */

#ifndef nsCSSParser_h___
#define nsCSSParser_h___

#include "nsAString.h"
#include "nsCSSProperty.h"
#include "nsColor.h"
#include "nsCOMArray.h"

class nsICSSRule;
class nsICSSStyleRule;
class nsICSSStyleSheet;
class nsIPrincipal;
class nsIURI;
class nsIUnicharInputStream;
class nsCSSDeclaration;
struct nsCSSSelectorList;
class nsMediaList;

namespace mozilla {
namespace css {
  class Loader;
}
}

// Interface to the css parser.

class NS_STACK_CLASS nsCSSParser {
public:
  nsCSSParser(mozilla::css::Loader* aLoader = nsnull,
              nsICSSStyleSheet* aSheet = nsnull);
  ~nsCSSParser();

  static void Shutdown();

private:
  // not to be implemented
  nsCSSParser(nsCSSParser const&);
  nsCSSParser& operator=(nsCSSParser const&);

public:
  // If this is false, memory allocation failed in the constructor
  // and all other methods will crash.
  operator bool() const
  { return !!mImpl; }

  // Set a style sheet for the parser to fill in. The style sheet must
  // implement the nsICSSStyleSheet interface.  Null can be passed in to clear
  // out an existing stylesheet reference.
  nsresult SetStyleSheet(nsICSSStyleSheet* aSheet);

  // Set whether or not to emulate Nav quirks
  nsresult SetQuirkMode(PRBool aQuirkMode);

#ifdef  MOZ_SVG
  // Set whether or not we are in an SVG element
  nsresult SetSVGMode(PRBool aSVGMode);
#endif

  // Set loader to use for child sheets
  nsresult SetChildLoader(mozilla::css::Loader* aChildLoader);

  /**
   * Parse aInput into the stylesheet that was previously set by calling
   * SetStyleSheet.  Calling this method without calling SetStyleSheet first is
   * an error.
   *
   * @param aInput the data to parse
   * @param aSheetURL the URI to use as the sheet URI (for error reporting).
   *                  This must match the URI of the sheet passed to
   *                  SetStyleSheet.
   * @param aBaseURI the URI to use for relative URI resolution
   * @param aSheetPrincipal the principal of the stylesheet.  This must match
   *                        the principal of the sheet passed to SetStyleSheet.
   * @param aLineNumber the line number of the first line of the sheet.
   * @param aAllowUnsafeRules see aEnableUnsafeRules in
   *                          mozilla::css::Loader::LoadSheetSync
   */
  nsresult Parse(nsIUnicharInputStream* aInput,
                 nsIURI*                aSheetURL,
                 nsIURI*                aBaseURI,
                 nsIPrincipal*          aSheetPrincipal,
                 PRUint32               aLineNumber,
                 PRBool                 aAllowUnsafeRules);

  // Parse HTML style attribute or its equivalent in other markup
  // languages.  aBaseURL is the base url to use for relative links in
  // the declaration.
  nsresult ParseStyleAttribute(const nsAString&  aAttributeValue,
                               nsIURI*           aDocURL,
                               nsIURI*           aBaseURL,
                               nsIPrincipal*     aNodePrincipal,
                               nsICSSStyleRule** aResult);

  nsresult ParseAndAppendDeclaration(const nsAString&  aBuffer,
                                     nsIURI*           aSheetURL,
                                     nsIURI*           aBaseURL,
                                     nsIPrincipal*     aSheetPrincipal,
                                     nsCSSDeclaration* aDeclaration,
                                     PRBool            aParseOnlyOneDecl,
                                     PRBool*           aChanged,
                                     PRBool            aClearOldDecl);

  nsresult ParseRule(const nsAString&        aRule,
                     nsIURI*                 aSheetURL,
                     nsIURI*                 aBaseURL,
                     nsIPrincipal*           aSheetPrincipal,
                     nsCOMArray<nsICSSRule>& aResult);

  nsresult ParseProperty(const nsCSSProperty aPropID,
                         const nsAString&    aPropValue,
                         nsIURI*             aSheetURL,
                         nsIURI*             aBaseURL,
                         nsIPrincipal*       aSheetPrincipal,
                         nsCSSDeclaration*   aDeclaration,
                         PRBool*             aChanged,
                         PRBool              aIsImportant);

  /**
   * Parse aBuffer into a media list |aMediaList|, which must be
   * non-null, replacing its current contents.  If aHTMLMode is true,
   * parse according to HTML rules, with commas as the most important
   * delimiter.  Otherwise, parse according to CSS rules, with
   * parentheses and strings more important than commas.  |aURL| and
   * |aLineNumber| are used for error reporting.
   */
  nsresult ParseMediaList(const nsSubstring& aBuffer,
                          nsIURI*            aURL,
                          PRUint32           aLineNumber,
                          nsMediaList*       aMediaList,
                          PRBool             aHTMLMode);

  /**
   * Parse aBuffer into a nscolor |aColor|.  The alpha component of the
   * resulting aColor may vary due to rgba()/hsla().  Will return
   * NS_ERROR_FAILURE if aBuffer is not a valid CSS color specification.
   *
   * Will also currently return NS_ERROR_FAILURE if it is not
   * self-contained (i.e.  doesn't reference any external style state,
   * such as "initial" or "inherit").
   */
  nsresult ParseColorString(const nsSubstring& aBuffer,
                            nsIURI*            aURL,
                            PRUint32           aLineNumber,
                            nscolor*           aColor);

  /**
   * Parse aBuffer into a selector list.  On success, caller must
   * delete *aSelectorList when done with it.
   */
  nsresult ParseSelectorString(const nsSubstring&  aSelectorString,
                               nsIURI*             aURL,
                               PRUint32            aLineNumber,
                               nsCSSSelectorList** aSelectorList);

protected:
  // This is a CSSParserImpl*, but if we expose that type name in this
  // header, we can't put the type definition (in nsCSSParser.cpp) in
  // the anonymous namespace.
  void* mImpl;
};

#endif /* nsCSSParser_h___ */