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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
#ifndef DOM_SVG_SVGLENGTH_H_
#define DOM_SVG_SVGLENGTH_H_
#include "nsDebug.h"
#include "nsMathUtils.h"
#include "mozilla/FloatingPoint.h"
#include "mozilla/dom/SVGAnimatedLength.h"
#include "mozilla/dom/SVGLengthBinding.h"
enum nsCSSUnit : uint32_t;
namespace mozilla {
namespace dom {
class SVGElement;
}
/**
* This SVGLength class is currently used for SVGLength *list* attributes only.
* The class that is currently used for <length> attributes is
* SVGAnimatedLength.
*
* The member mUnit should always be valid, but the member mValue may be
* numeric_limits<float>::quiet_NaN() under one circumstances (see the comment
* in SetValueAndUnit below). Even if mValue is valid, some methods may return
* numeric_limits<float>::quiet_NaN() if they involve a unit conversion that
* fails - see comments below.
*
* The DOM wrapper class for this class is DOMSVGLength.
*/
class SVGLength {
public:
SVGLength()
: mValue(0.0f), mUnit(dom::SVGLength_Binding::SVG_LENGTHTYPE_UNKNOWN) {}
SVGLength(float aValue, uint8_t aUnit) : mValue(aValue), mUnit(aUnit) {}
bool operator==(const SVGLength& rhs) const {
return mValue == rhs.mValue && mUnit == rhs.mUnit;
}
void GetValueAsString(nsAString& aValue) const;
/**
* This method returns true, unless there was a parse failure, in which
* case it returns false (and the length is left unchanged).
*/
bool SetValueFromString(const nsAString& aString);
/**
* This will usually return a valid, finite number. There is one exception
* though. If SVGLengthListSMILType has to convert between unit types and the
* unit conversion is undefined, it will end up passing in and setting
* numeric_limits<float>::quiet_NaN(). The painting code has to be
* able to handle NaN anyway, since conversion to user units may fail in
* general.
*/
float GetValueInCurrentUnits() const { return mValue; }
uint8_t GetUnit() const { return mUnit; }
void SetValueInCurrentUnits(float aValue) {
NS_ASSERTION(std::isfinite(aValue), "Set invalid SVGLength");
mValue = aValue;
}
void SetValueAndUnit(float aValue, uint8_t aUnit) {
mValue = aValue;
mUnit = aUnit;
}
/**
* If it's not possible to convert this length's value to pixels, then
* this method will return numeric_limits<float>::quiet_NaN().
*/
float GetValueInPixels(const dom::SVGElement* aElement, uint8_t aAxis) const {
return mValue * GetPixelsPerUnit(dom::SVGElementMetrics(aElement), aAxis);
}
/**
* Get this length's value in the units specified.
*
* This method returns numeric_limits<float>::quiet_NaN() if it is not
* possible to convert the value to the specified unit.
*/
float GetValueInSpecifiedUnit(uint8_t aUnit, const dom::SVGElement* aElement,
uint8_t aAxis) const;
bool IsPercentage() const { return IsPercentageUnit(mUnit); }
float GetPixelsPerUnit(const dom::UserSpaceMetrics& aMetrics,
uint8_t aAxis) const {
return GetPixelsPerUnit(aMetrics, mUnit, aAxis);
}
static bool IsValidUnitType(uint16_t aUnitType) {
return aUnitType > dom::SVGLength_Binding::SVG_LENGTHTYPE_UNKNOWN &&
aUnitType <= dom::SVGLength_Binding::SVG_LENGTHTYPE_PC;
}
static bool IsPercentageUnit(uint8_t aUnit) {
return aUnit == dom::SVGLength_Binding::SVG_LENGTHTYPE_PERCENTAGE;
}
static bool IsAbsoluteUnit(uint8_t aUnit);
static bool IsFontRelativeUnit(uint8_t aUnit);
static float GetAbsUnitsPerAbsUnit(uint8_t aUnits, uint8_t aPerUnit);
static nsCSSUnit SpecifiedUnitTypeToCSSUnit(uint8_t aSpecifiedUnit);
static void GetUnitString(nsAString& aUnit, uint16_t aUnitType);
static uint16_t GetUnitTypeForString(const nsAString& aUnit);
/**
* Returns the number of pixels per given unit.
*/
static float GetPixelsPerUnit(const dom::UserSpaceMetrics& aMetrics,
uint8_t aUnitType, uint8_t aAxis);
private:
float mValue;
uint8_t mUnit;
};
} // namespace mozilla
#endif // DOM_SVG_SVGLENGTH_H_