/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

/* vim: set ts=8 sts=2 et sw=2 tw=80: */

/* This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef nsStyleUtil_h___

#define nsStyleUtil_h___

#include "nsCoord.h"

#include "nsCSSPropertyID.h"

#include "nsTArrayForwardDeclare.h"

#include "gfxFontFamilyList.h"

#include "nsStringFwd.h"

#include "nsStyleStruct.h"

#include "nsCRT.h"

class nsCSSValue;

class nsStyleCoord;

class nsIContent;

class nsIPrincipal;

class nsIURI;

struct gfxFontFeature;

struct gfxAlternateValue;

struct nsCSSKTableEntry;

struct nsCSSValueList;

namespace mozilla {

class FontSlantStyle;

namespace dom {

class Element;

}

}

// Style utility functions

class nsStyleUtil {

public:

 static bool DashMatchCompare(const nsAString& aAttributeValue,

                                const nsAString& aSelectorValue,

                                const nsStringComparator& aComparator);

 static bool ValueIncludes(const nsAString& aValueList,

                           const nsAString& aValue,

                           const nsStringComparator& aComparator);

  // Append a quoted (with 'quoteChar') and escaped version of aString

  // to aResult.  'quoteChar' must be ' or ".

  static void AppendEscapedCSSString(const nsAString& aString,

                                     nsAString& aResult,

                                     char16_t quoteChar = '"');

  // Append the identifier given by |aIdent| to |aResult|, with

  // appropriate escaping so that it can be reparsed to the same

  // identifier.  An exception is if aIdent contains U+0000, which

  // will be escaped as U+FFFD and then reparsed back to U+FFFD.

  static void AppendEscapedCSSIdent(const nsAString& aIdent,

                                    nsAString& aResult);

  static void

  AppendFontSlantStyle(const mozilla::FontSlantStyle&, nsAString& aResult);

public:

  // Append a bitmask-valued property's value(s) (space-separated) to aResult.

  static void AppendBitmaskCSSValue(const nsCSSKTableEntry aTable[],

                                    int32_t aMaskedValue,

                                    int32_t aFirstMask,

                                    int32_t aLastMask,

                                    nsAString& aResult);

  static void AppendAngleValue(const nsStyleCoord& aValue, nsAString& aResult);

  static void AppendPaintOrderValue(uint8_t aValue, nsAString& aResult);

  static void AppendCSSNumber(float aNumber, nsAString& aResult)

  {

    aResult.AppendFloat(aNumber);

  }

  static void AppendStepsTimingFunction(nsTimingFunction::Type aType,

                                        uint32_t aSteps,

                                        nsAString& aResult);

  static void AppendFramesTimingFunction(uint32_t aFrames,

                                         nsAString& aResult);

  static void AppendCubicBezierTimingFunction(float aX1, float aY1,

                                              float aX2, float aY2,

                                              nsAString& aResult);

  static void AppendCubicBezierKeywordTimingFunction(

      nsTimingFunction::Type aType,

      nsAString& aResult);

  /*

   * Convert an author-provided floating point number to an integer (0

   * ... 255) appropriate for use in the alpha component of a color.

   */

  static uint8_t FloatToColorComponent(float aAlpha)

  {

    NS_ASSERTION(0.0 <= aAlpha && aAlpha <= 1.0, "out of range");

    return NSToIntRound(aAlpha * 255);

  }

  /*

   * Convert the alpha component of an nscolor (0 ... 255) to the

   * floating point number with the least accurate *decimal*

   * representation that is converted to that color.

   *

   * Should be used only by serialization code.

   */

  static float ColorComponentToFloat(uint8_t aAlpha);

  /*

   * Does this child count as significant for selector matching?

   */

  static bool IsSignificantChild(nsIContent* aChild,

                                 bool aWhitespaceIsSignificant);

  /*

   * Thread-safe version of IsSignificantChild()

   */

  static bool ThreadSafeIsSignificantChild(const nsIContent* aChild,

                                           bool aWhitespaceIsSignificant);

  /**

   * Returns true if our object-fit & object-position properties might cause

   * a replaced element's contents to overflow its content-box (requiring

   * clipping), or false if we can be sure that this won't happen.

   *

   * This lets us optimize by skipping clipping when we can tell it's

   * unnecessary (particularly with the default values of these properties).

   *

   * @param aStylePos The nsStylePosition whose object-fit & object-position

   *                  properties should be checked for potential overflow.

   * @return false if we can be sure that the object-fit & object-position

   *         properties on 'aStylePos' cannot cause a replaced element's

   *         contents to overflow its content-box. Otherwise (if overflow is

   *         is possible), returns true.

   */

  static bool ObjectPropsMightCauseOverflow(const nsStylePosition* aStylePos);

  /*

   *  Does this principal have a CSP that blocks the application of

   *  inline styles? Returns false if application of the style should

   *  be blocked.

   *

   *  @param aContent

   *      The <style> element that the caller wants to know whether to honor.

   *      Included to check the nonce attribute if one is provided. Allowed to

   *      be null, if this is for something other than a <style> element (in

   *      which case nonces won't be checked).

   *  @param aPrincipal

   *      The principal of the of the document (*not* of the style sheet).

   *      The document's principal is where any Content Security Policy that

   *      should be used to block or allow inline styles will be located.

   *  @param aTriggeringPrincipal

   *      The principal of the scripted caller which added the inline

   *      stylesheet, or null if no scripted caller can be identified.

   *  @param aSourceURI

   *      URI of document containing inline style (for reporting violations)

   *  @param aLineNumber

   *      Line number of inline style element in the containing document (for

   *      reporting violations)

   *  @param aColumnNumber

   *      Column number of inline style element in the containing document (for

   *      reporting violations)

   *  @param aStyleText

   *      Contents of the inline style element (for reporting violations)

   *  @param aRv

   *      Return error code in case of failure

   *  @return

   *      Does CSP allow application of the specified inline style?

   */

  static bool CSPAllowsInlineStyle(mozilla::dom::Element* aContent,

                                   nsIPrincipal* aPrincipal,

                                   nsIPrincipal* aTriggeringPrincipal,

                                   nsIURI* aSourceURI,

                                   uint32_t aLineNumber,

                                   uint32_t aColumnNumber,

                                   const nsAString& aStyleText,

                                   nsresult* aRv);

  template<size_t N>

  static bool MatchesLanguagePrefix(const char16_t* aLang, size_t aLen,

                                    const char16_t (&aPrefix)[N])

  {

    return !NS_strncmp(aLang, aPrefix, N - 1) &&

           (aLen == N - 1 || aLang[N - 1] == '-');

  }

  template<size_t N>

  static bool MatchesLanguagePrefix(const nsAtom* aLang,

                                    const char16_t (&aPrefix)[N])

  {

    MOZ_ASSERT(aLang);

    return MatchesLanguagePrefix(aLang->GetUTF16String(),

                                 aLang->GetLength(), aPrefix);

  }

  template<size_t N>

  static bool MatchesLanguagePrefix(const nsAString& aLang,

                                    const char16_t (&aPrefix)[N])

  {

    return MatchesLanguagePrefix(aLang.Data(), aLang.Length(), aPrefix);

  }

};

#endif /* nsStyleUtil_h___ */