gecko-dev/layout/style/nsCSSValue.h

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/* -*- 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/. */
/* representation of simple property values within CSS declarations */
#ifndef nsCSSValue_h___
#define nsCSSValue_h___
#include "mozilla/Attributes.h"
#include "mozilla/CORSMode.h"
#include "mozilla/EnumTypeTraits.h"
#include "mozilla/FontPropertyTypes.h"
#include "mozilla/MemoryReporting.h"
#include "mozilla/ServoBindingTypes.h"
#include "mozilla/URLExtraData.h"
#include "mozilla/UniquePtr.h"
#include "nsCoord.h"
#include "nsTArray.h"
#include <type_traits>
// XXX Avoid including this here by moving function bodies to the cpp file
#include "mozilla/FloatingPoint.h"
class imgRequestProxy;
class nsAtom;
class nsIContent;
class nsIPrincipal;
class nsIURI;
class nsPresContext;
template <class T>
class nsPtrHashKey;
struct RawServoCssUrlData;
namespace mozilla {
class CSSStyleSheet;
} // namespace mozilla
// Forward declaration copied here since ServoBindings.h #includes nsCSSValue.h.
extern "C" {
mozilla::URLExtraData* Servo_CssUrlData_GetExtraData(const RawServoCssUrlData*);
bool Servo_CssUrlData_IsLocalRef(const RawServoCssUrlData* url);
}
enum nsCSSUnit : uint32_t {
eCSSUnit_Null = 0, // (n/a) null unit, value is not specified
eCSSUnit_Integer = 70, // (int) simple value
eCSSUnit_Enumerated = 71, // (int) value has enumerated meaning
eCSSUnit_Percent = 100, // (float) (1.0 == 100%) value is percentage of
// something
eCSSUnit_Number = 101, // (float) value is numeric (usually multiplier,
// different behavior than percent)
// Font relative measure
eCSSUnit_EM = 800, // (float) == current font size
eCSSUnit_XHeight = 801, // (float) distance from top of lower case x to
// baseline
eCSSUnit_Char = 802, // (float) number of characters, used for width with
// monospace font
eCSSUnit_RootEM = 803, // (float) == root element font size
// Screen relative measure
eCSSUnit_Point = 900, // (float) 4/3 of a CSS pixel
eCSSUnit_Inch = 901, // (float) 96 CSS pixels
eCSSUnit_Millimeter = 902, // (float) 96/25.4 CSS pixels
eCSSUnit_Centimeter = 903, // (float) 96/2.54 CSS pixels
eCSSUnit_Pica = 904, // (float) 12 points == 16 CSS pixls
eCSSUnit_Quarter = 905, // (float) 96/101.6 CSS pixels
eCSSUnit_Pixel = 906, // (float) CSS pixel unit
// Angular units
eCSSUnit_Degree = 1000, // (float) 360 per circle
// Frequency units
eCSSUnit_Hertz = 2000, // (float) 1/seconds
eCSSUnit_Kilohertz = 2001, // (float) 1000 Hertz
// Time units
eCSSUnit_Seconds = 3000, // (float) Standard time
eCSSUnit_Milliseconds = 3001, // (float) 1/1000 second
// Flexible fraction (CSS Grid)
eCSSUnit_FlexFraction = 4000, // (float) Fraction of free space
};
struct nsCSSValuePair;
struct nsCSSValuePair_heap;
struct nsCSSValueList;
struct nsCSSValueList_heap;
struct nsCSSValueSharedList;
struct nsCSSValuePairList;
struct nsCSSValuePairList_heap;
class nsCSSValue {
public:
explicit nsCSSValue() : mUnit(eCSSUnit_Null) {}
nsCSSValue(int32_t aValue, nsCSSUnit aUnit);
nsCSSValue(float aValue, nsCSSUnit aUnit);
nsCSSValue(const nsCSSValue& aCopy);
nsCSSValue(nsCSSValue&& aOther) : mUnit(aOther.mUnit), mValue(aOther.mValue) {
aOther.mUnit = eCSSUnit_Null;
}
template <typename T, typename = std::enable_if_t<std::is_enum<T>::value>>
explicit nsCSSValue(T aValue) : mUnit(eCSSUnit_Enumerated) {
static_assert(mozilla::EnumTypeFitsWithin<T, int32_t>::value,
"aValue must be an enum that fits within mValue.mInt");
mValue.mInt = static_cast<int32_t>(aValue);
}
nsCSSValue& operator=(const nsCSSValue& aCopy);
nsCSSValue& operator=(nsCSSValue&& aCopy);
bool operator==(const nsCSSValue& aOther) const;
bool operator!=(const nsCSSValue& aOther) const { return !(*this == aOther); }
nsCSSUnit GetUnit() const { return mUnit; }
bool IsLengthUnit() const {
return eCSSUnit_EM <= mUnit && mUnit <= eCSSUnit_Pixel;
}
bool IsLengthPercentUnit() const {
return IsLengthUnit() || mUnit == eCSSUnit_Percent;
}
/**
* What the spec calls relative length units is, for us, split
* between relative length units and pixel length units.
*
* A "relative" length unit is a multiple of some derived metric,
* such as a font em-size, which itself was controlled by an input CSS
* length. Relative length units should not be scaled by zooming, since
* the underlying CSS length would already have been scaled.
*/
bool IsRelativeLengthUnit() const {
return eCSSUnit_EM <= mUnit && mUnit <= eCSSUnit_RootEM;
}
/**
* A "pixel" length unit is a some multiple of CSS pixels.
*/
static bool IsPixelLengthUnit(nsCSSUnit aUnit) {
return eCSSUnit_Point <= aUnit && aUnit <= eCSSUnit_Pixel;
}
bool IsPixelLengthUnit() const { return IsPixelLengthUnit(mUnit); }
static bool IsPercentLengthUnit(nsCSSUnit aUnit) {
return aUnit == eCSSUnit_Percent;
}
bool IsPercentLengthUnit() { return IsPercentLengthUnit(mUnit); }
static bool IsFloatUnit(nsCSSUnit aUnit) { return eCSSUnit_Number <= aUnit; }
bool IsAngularUnit() const { return eCSSUnit_Degree == mUnit; }
bool IsFrequencyUnit() const {
return eCSSUnit_Hertz <= mUnit && mUnit <= eCSSUnit_Kilohertz;
}
bool IsTimeUnit() const {
return eCSSUnit_Seconds <= mUnit && mUnit <= eCSSUnit_Milliseconds;
}
int32_t GetIntValue() const {
MOZ_ASSERT(mUnit == eCSSUnit_Integer || mUnit == eCSSUnit_Enumerated,
"not an int value");
return mValue.mInt;
}
float GetPercentValue() const {
MOZ_ASSERT(mUnit == eCSSUnit_Percent, "not a percent value");
return mValue.mFloat;
}
float GetFloatValue() const {
MOZ_ASSERT(eCSSUnit_Number <= mUnit, "not a float value");
MOZ_ASSERT(!mozilla::IsNaN(mValue.mFloat));
return mValue.mFloat;
}
float GetAngleValue() const {
MOZ_ASSERT(eCSSUnit_Degree == mUnit, "not an angle value");
return mValue.mFloat;
}
// Converts any angle to radians.
double GetAngleValueInRadians() const;
// Converts any angle to degrees.
double GetAngleValueInDegrees() const;
nscoord GetPixelLength() const;
void Reset() { mUnit = eCSSUnit_Null; }
~nsCSSValue() { Reset(); }
public:
void SetIntValue(int32_t aValue, nsCSSUnit aUnit);
template <typename T, typename = std::enable_if_t<std::is_enum<T>::value>>
void SetEnumValue(T aValue) {
static_assert(mozilla::EnumTypeFitsWithin<T, int32_t>::value,
"aValue must be an enum that fits within mValue.mInt");
SetIntValue(static_cast<int32_t>(aValue), eCSSUnit_Enumerated);
}
void SetPercentValue(float aValue);
void SetFloatValue(float aValue, nsCSSUnit aUnit);
// converts the nscoord to pixels
void SetIntegerCoordValue(nscoord aCoord);
protected:
nsCSSUnit mUnit;
union {
int32_t mInt;
float mFloat;
} mValue;
};
#endif /* nsCSSValue_h___ */