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Diffstat (limited to '')
-rw-r--r-- | dom/svg/SVGLength.h | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/dom/svg/SVGLength.h b/dom/svg/SVGLength.h new file mode 100644 index 0000000000..34611ee86f --- /dev/null +++ b/dom/svg/SVGLength.h @@ -0,0 +1,137 @@ +/* -*- 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 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_ |