firefox-main/layout/svg/SVGImageContext.h (file symbol)

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/* 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 LAYOUT_SVG_SVGIMAGECONTEXT_H_
#define LAYOUT_SVG_SVGIMAGECONTEXT_H_
#include "Units.h"
#include "mozilla/Casting.h"
#include "mozilla/Maybe.h"
#include "mozilla/SVGContextPaint.h"
#include "mozilla/SVGPreserveAspectRatio.h"
class nsIFrame;
class nsISVGPaintContext;
namespace mozilla {
enum class ColorScheme : uint8_t;
class ComputedStyle;
// SVG image-specific rendering context. For imgIContainer::Draw.
// Used to pass information such as
// - viewport and color-scheme information from CSS, and
// - overridden attributes from an SVG <image> element
// to the image's internal SVG document when it's drawn.
class SVGImageContext {
public:
SVGImageContext() = default;
/**
* Currently it seems that the aViewportSize parameter ends up being used
* for different things by different pieces of code, and probably in some
* cases being used incorrectly (specifically in the case of pixel snapping
* under the nsLayoutUtils::Draw*Image() methods). An unfortunate result of
* the messy code is that aViewportSize is currently a Maybe<T> since it
* is difficult to create a utility function that consumers can use up
* front to get the "correct" viewport size (i.e. which for compatibility
* with the current code (bugs and all) would mean the size including all
* the snapping and resizing magic that happens in various places under the
* nsLayoutUtils::Draw*Image() methods on the way to DrawImageInternal
* creating |fallbackContext|). Using Maybe<T> allows code to pass Nothing()
* in order to get the size that's created for |fallbackContext|. At some
* point we need to clean this code up, make our abstractions clear, create
* that utility and stop using Maybe for this parameter.
*/
explicit SVGImageContext(
const Maybe<CSSSize>& aViewportSize,
const Maybe<SVGPreserveAspectRatio>& aPreserveAspectRatio = Nothing(),
const Maybe<ColorScheme>& aColorScheme = Nothing())
: mViewportSize(aViewportSize),
mPreserveAspectRatio(aPreserveAspectRatio),
mColorScheme(aColorScheme) {}
static void MaybeStoreContextPaint(SVGImageContext& aContext,
nsIFrame* aFromFrame,
imgIContainer* aImgContainer);
static void MaybeStoreContextPaint(SVGImageContext& aContext,
const nsPresContext&, const ComputedStyle&,
imgIContainer*);
static void MaybeStoreContextPaint(SVGImageContext& aContext,
nsISVGPaintContext* aPaintContext,
imgIContainer* aImgContainer);
const Maybe<CSSSize>& GetViewportSize() const { return mViewportSize; }
void SetViewportSize(const Maybe<CSSSize>& aSize) { mViewportSize = aSize; }
const Maybe<ColorScheme>& GetColorScheme() const { return mColorScheme; }
void SetColorScheme(const Maybe<ColorScheme>& aScheme) {
mColorScheme = aScheme;
}
const Maybe<SVGPreserveAspectRatio>& GetPreserveAspectRatio() const {
return mPreserveAspectRatio;
}
void SetPreserveAspectRatio(const Maybe<SVGPreserveAspectRatio>& aPAR) {
mPreserveAspectRatio = aPAR;
}
const StyleLinkParameters& GetLinkParameters() const {
return mLinkParameters;
}
void SetLinkParameters(const StyleLinkParameters& aLinkParameters) {
mLinkParameters = aLinkParameters;
}
const SVGContextPaint* GetContextPaint() const { return mContextPaint.get(); }
void SetContextPaint(Maybe<nscolor> aFill, Maybe<nscolor> aStroke) {
mContextPaint = MakeRefPtr<SVGContextPaint>(aFill, aStroke);
}
void ClearContextPaint() { mContextPaint = nullptr; }
bool operator==(const SVGImageContext& aOther) const {
bool contextPaintIsEqual =
// neither have context paint, or they have the same object:
(mContextPaint == aOther.mContextPaint) ||
// or both have context paint that are different but equivalent objects:
(mContextPaint && aOther.mContextPaint &&
*mContextPaint == *aOther.mContextPaint);
return contextPaintIsEqual && mViewportSize == aOther.mViewportSize &&
mPreserveAspectRatio == aOther.mPreserveAspectRatio &&
mColorScheme == aOther.mColorScheme &&
mLinkParameters == aOther.mLinkParameters;
}
PLDHashNumber Hash() const {
PLDHashNumber hash = 0;
if (mContextPaint) {
hash = AddToHash(hash, mContextPaint->Hash());
}
return AddToHash(hash, mViewportSize.map(HashSize).valueOr(0),
mPreserveAspectRatio.map(HashPAR).valueOr(0),
mColorScheme.map(HashColorScheme).valueOr(0),
HashLinkParameters(mLinkParameters));
}
private:
static PLDHashNumber HashSize(const CSSSize& aSize) {
return HashGeneric(BitwiseCast<uint32_t>(aSize.width),
BitwiseCast<uint32_t>(aSize.height));
}
static PLDHashNumber HashPAR(const SVGPreserveAspectRatio& aPAR) {
return aPAR.Hash();
}
static PLDHashNumber HashColorScheme(ColorScheme aScheme) {
return HashGeneric(uint8_t(aScheme));
}
static PLDHashNumber HashLinkParam(const StyleLinkParam& aLinkParam) {
return AddToHash(aLinkParam.name.AsAtom()->hash(),
HashString(aLinkParam.value.AsString()));
}
static PLDHashNumber HashLinkParameters(
const StyleLinkParameters& aLinkParameters) {
PLDHashNumber hash = 0;
for (const auto& p : aLinkParameters._0.AsSpan()) {
hash = AddToHash(hash, HashLinkParam(p));
}
return hash;
}
// NOTE: When adding new member-vars, remember to update Hash() & operator==.
RefPtr<SVGContextPaint> mContextPaint;
Maybe<CSSSize> mViewportSize;
Maybe<SVGPreserveAspectRatio> mPreserveAspectRatio;
Maybe<ColorScheme> mColorScheme;
StyleLinkParameters mLinkParameters;
};
} // namespace mozilla
#endif // LAYOUT_SVG_SVGIMAGECONTEXT_H_