gecko-dev/layout/svg/SVGContextPaint.h

262 lines
9.0 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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 MOZILLA_SVGCONTEXTPAINT_H_
#define MOZILLA_SVGCONTEXTPAINT_H_
#include "DrawMode.h"
#include "gfxMatrix.h"
#include "gfxPattern.h"
#include "gfxTypes.h"
#include "mozilla/AlreadyAddRefed.h"
#include "mozilla/Assertions.h"
#include "mozilla/gfx/2D.h"
#include "nsColor.h"
#include "nsStyleStruct.h"
#include "nsTArray.h"
class gfxContext;
class nsIDocument;
class nsSVGPaintServerFrame;
namespace mozilla {
/**
* This class is used to pass information about a context element through to
* SVG painting code in order to resolve the 'context-fill' and related
* keywords. See:
*
* https://www.w3.org/TR/SVG2/painting.html#context-paint
*
* This feature allows the color in an SVG-in-OpenType glyph to come from the
* computed style for the text that is being drawn, for example, or for color
* in an SVG embedded by an <img> element to come from the embedding <img>
* element.
*
* This class is reference counted so that it can be shared among many similar
* SVGImageContext objects. (SVGImageContext objects are frequently
* copy-constructed with small modifications, and we'd like for those copies to
* be able to share their context-paint data cheaply.) However, in most cases,
* SVGContextPaint instances are stored in a local RefPtr and only last for the
* duration of a function call.
* XXX Note: SVGImageContext doesn't actually have a SVGContextPaint member yet,
* but it will in a later patch in the patch series that added this comment.
*/
class SVGContextPaint : public RefCounted<SVGContextPaint>
{
protected:
typedef mozilla::gfx::DrawTarget DrawTarget;
SVGContextPaint() {}
public:
MOZ_DECLARE_REFCOUNTED_TYPENAME(SVGContextPaint)
virtual ~SVGContextPaint() {}
virtual already_AddRefed<gfxPattern> GetFillPattern(const DrawTarget* aDrawTarget,
float aOpacity,
const gfxMatrix& aCTM) = 0;
virtual already_AddRefed<gfxPattern> GetStrokePattern(const DrawTarget* aDrawTarget,
float aOpacity,
const gfxMatrix& aCTM) = 0;
virtual float GetFillOpacity() const = 0;
virtual float GetStrokeOpacity() const = 0;
already_AddRefed<gfxPattern> GetFillPattern(const DrawTarget* aDrawTarget,
const gfxMatrix& aCTM) {
return GetFillPattern(aDrawTarget, GetFillOpacity(), aCTM);
}
already_AddRefed<gfxPattern> GetStrokePattern(const DrawTarget* aDrawTarget,
const gfxMatrix& aCTM) {
return GetStrokePattern(aDrawTarget, GetStrokeOpacity(), aCTM);
}
static SVGContextPaint* GetContextPaint(nsIContent* aContent);
// XXX This gets the geometry params from the gfxContext. We should get that
// information from the actual paint context!
void InitStrokeGeometry(gfxContext *aContext,
float devUnitsPerSVGUnit);
FallibleTArray<gfxFloat>& GetStrokeDashArray() {
return mDashes;
}
gfxFloat GetStrokeDashOffset() {
return mDashOffset;
}
gfxFloat GetStrokeWidth() {
return mStrokeWidth;
}
virtual uint32_t Hash() const {
MOZ_ASSERT_UNREACHABLE("Only VectorImage needs to hash, and that should "
"only be operating on our SVGEmbeddingContextPaint "
"subclass");
return 0;
}
private:
// Member-vars are initialized in InitStrokeGeometry.
FallibleTArray<gfxFloat> mDashes;
MOZ_INIT_OUTSIDE_CTOR gfxFloat mDashOffset;
MOZ_INIT_OUTSIDE_CTOR gfxFloat mStrokeWidth;
};
/**
* RAII class used to temporarily set and remove an SVGContextPaint while a
* piece of SVG is being painted. The context paint is set on the SVG's owner
* document, as expected by SVGContextPaint::GetContextPaint. Any pre-existing
* context paint is restored after this class removes the context paint that it
* set.
*/
class MOZ_RAII AutoSetRestoreSVGContextPaint
{
public:
AutoSetRestoreSVGContextPaint(const SVGContextPaint* aContextPaint,
nsIDocument* aSVGDocument);
~AutoSetRestoreSVGContextPaint();
private:
nsIDocument* mSVGDocument;
// The context paint that needs to be restored by our dtor after it removes
// aContextPaint:
void* mOuterContextPaint;
};
/**
* This class should be flattened into SVGContextPaint once we get rid of the
* other sub-class (SimpleTextContextPaint).
*/
struct SVGContextPaintImpl : public SVGContextPaint
{
protected:
typedef mozilla::gfx::DrawTarget DrawTarget;
public:
DrawMode Init(const DrawTarget* aDrawTarget,
const gfxMatrix& aContextMatrix,
nsIFrame* aFrame,
SVGContextPaint* aOuterContextPaint);
already_AddRefed<gfxPattern> GetFillPattern(const DrawTarget* aDrawTarget,
float aOpacity,
const gfxMatrix& aCTM) override;
already_AddRefed<gfxPattern> GetStrokePattern(const DrawTarget* aDrawTarget,
float aOpacity,
const gfxMatrix& aCTM) override;
void SetFillOpacity(float aOpacity) { mFillOpacity = aOpacity; }
float GetFillOpacity() const override { return mFillOpacity; }
void SetStrokeOpacity(float aOpacity) { mStrokeOpacity = aOpacity; }
float GetStrokeOpacity() const override { return mStrokeOpacity; }
struct Paint {
Paint() : mPaintType(eStyleSVGPaintType_None) {}
void SetPaintServer(nsIFrame* aFrame,
const gfxMatrix& aContextMatrix,
nsSVGPaintServerFrame* aPaintServerFrame) {
mPaintType = eStyleSVGPaintType_Server;
mPaintDefinition.mPaintServerFrame = aPaintServerFrame;
mFrame = aFrame;
mContextMatrix = aContextMatrix;
}
void SetColor(const nscolor &aColor) {
mPaintType = eStyleSVGPaintType_Color;
mPaintDefinition.mColor = aColor;
}
void SetContextPaint(SVGContextPaint* aContextPaint,
nsStyleSVGPaintType aPaintType) {
NS_ASSERTION(aPaintType == eStyleSVGPaintType_ContextFill ||
aPaintType == eStyleSVGPaintType_ContextStroke,
"Invalid context paint type");
mPaintType = aPaintType;
mPaintDefinition.mContextPaint = aContextPaint;
}
union {
nsSVGPaintServerFrame* mPaintServerFrame;
SVGContextPaint* mContextPaint;
nscolor mColor;
} mPaintDefinition;
// Initialized (if needed) in SetPaintServer():
MOZ_INIT_OUTSIDE_CTOR nsIFrame* mFrame;
// CTM defining the user space for the pattern we will use.
gfxMatrix mContextMatrix;
nsStyleSVGPaintType mPaintType;
// Device-space-to-pattern-space
gfxMatrix mPatternMatrix;
nsRefPtrHashtable<nsFloatHashKey, gfxPattern> mPatternCache;
already_AddRefed<gfxPattern> GetPattern(const DrawTarget* aDrawTarget,
float aOpacity,
nsStyleSVGPaint nsStyleSVG::*aFillOrStroke,
const gfxMatrix& aCTM);
};
Paint mFillPaint;
Paint mStrokePaint;
float mFillOpacity;
float mStrokeOpacity;
};
/**
* This class is used to pass context paint to an SVG image when an element
* references that image (e.g. via HTML <img> or SVG <image>, or by referencing
* it from a CSS property such as 'background-image'). In this case we only
* support context colors and not paint servers.
*/
class SVGEmbeddingContextPaint : public SVGContextPaint
{
public:
SVGEmbeddingContextPaint() {}
void SetFill(nscolor aFill);
void SetStroke(nscolor aStroke);
already_AddRefed<gfxPattern> GetFillPattern(const DrawTarget* aDrawTarget,
float aOpacity,
const gfxMatrix& aCTM) override {
return do_AddRef(mFill);
}
already_AddRefed<gfxPattern> GetStrokePattern(const DrawTarget* aDrawTarget,
float aOpacity,
const gfxMatrix& aCTM) override {
return do_AddRef(mStroke);
}
float GetFillOpacity() const override {
// Always 1.0f since we don't currently allow 'context-fill-opacity'
return 1.0f;
};
float GetStrokeOpacity() const override {
// Always 1.0f since we don't currently allow 'context-stroke-opacity'
return 1.0f;
};
uint32_t Hash() const override;
private:
// Note: if these are set at all, they'll have type PatternType::COLOR.
RefPtr<gfxPattern> mFill;
RefPtr<gfxPattern> mStroke;
};
} // namespace mozilla
#endif // MOZILLA_SVGCONTEXTPAINT_H_